Climate Central - News

NOAA Satellite Malfunctions, May Affect Forecasts

2013-05-22T16:23:58+00:00

As the weather system that spawned the deadly Moore tornado moves eastward, the main weather satellite used for observing and forecasting conditions across eastern North America and the Atlantic Ocean has gone offline. It's the second malfunction since September 2012, when a technical glitch was fixed by engineers working from the ground.

According to the National Oceanic and Atmospheric Administration (NOAA), which operates the nation’s fleet of weather satellites, the satellite, known as GOES-13, initially malfunctioned at 11:40 p.m. eastern time on Tuesday. An initial recovery procedure was unsuccessful at restoring it to operation.

A NOAA rending of a GOES satellite.
Credit: NOAA.

According to a blog post from the University of Wisconsin’s Space Science and Engineering Center, the error centers around a mechanism that helps the satellite detects its orientation, or attitude, which is known as the “Star Tracker.” “The Star Tracker is not functioning, which means the satellite cannot find the Earth,” the blog post said.

The outage of this geostationary satellite — so named because the spacecraft stays in a fixed orbit above the equator — does not mean that forecasters have lost all of their weather imagery and data for the Atlantic Ocean and the East Coast. NOAA immediately put backup operations into place, and other satellites, including polar-orbiting satellites, can compensate for some of the lost data.

As occurred during the outage in September, NOAA first placed a satellite that covers the West Coast into “full disk scan” mode, which will allow it to take pictures of eastern areas once every half hour. NOAA is now maneuvering its backup GOES satellite into service to take over for the troubled GOES-13 as of Thursday morning.

Launched in 2006 but not put into service until 2010, GOES-13 should have several more years in service before it reaches the end of its design lifespan.

One of the biggest impacts from the brief degradation in satellite coverage could be felt in the area of computer modeling, since satellites are one of the main data sources for weather models. That could have an impact on the reliability of hurricane forecasts, in particular. Fortunately, there are no active tropical storms or hurricanes in the Atlantic, and the storm system moving from the Plains toward the East Coast is weakening.

NOAA accurately predicted Hurricane Sandy's path, in part because of weather satellite data.

The satellite outage, even if it only leads to a temporary interruption of routine weather data, offers another preview of what’s to come in a few years due to delays in the development of the next generation of polar-orbiting satellites. The delays mean that the polar satellite program won't have the redundancy that is present in the GOES program.

Polar-orbiting satellites continuously scan the planet from north to south, and instruments aboard these satellites are used for many applications in addition to weather forecasting, such as monitoring volcanic eruptions, gathering sea-surface temperature data, and locating emergency beacons from aviators or mariners in distress. NOAA has warned that a gap in polar satellite coverage could significantly degrade forecast accuracy, even retroactively forecasting Hurricane Sandy with and without the satellite data, to show how forecasts would have suffered.

NOAA has warned that starting in 2017 there will likely be at least a year-long gap between the newest polar orbiting satellite’s design lifetime and the scheduled launch date of its replacement.

That would mean the U.S. would be reliant on just one polar-orbiting satellite, rather than the two that have long been in service. NOAA ran up billions in cost overruns for the next generation of polar-orbiting weather satellites, and delays and congressional budget issues have put that program, known as the Joint Polar Satellite System (JPSS), years behind schedule.

“Gaps are opening in both our operational and research satellites,” J. Marshall Shepherd, director of the atmospheric sciences program at the University of Georgia a president of the American Meteorological Society, told Time.com. “If one of them goes out, it’s not like simply replacing a burned-out light bulb. These things take years to build and launch.”

When the GOES-13 satellite malfunctioned in September 2012, NOAA spokesman John Leslie downplayed the significance of the problem. "To put it into perspective, this is a technical anomaly, which is not unusual during the life of any satellite mission. NOAA continues to work with its partner, NASA, on the development and launch of the next-generation JPSS and GOES-R satellites," he said.

NOAA has not yet responded to requests for comment on the latest technical difficulties.

Limiting Methane Leaks Critical to Gas, Climate Benefits

2013-05-22T15:58:20+00:00

By Climate Central

Knowing how much methane is leaking from the natural gas system is essential to determining the potential climate benefits of natural gas use. Our extensive review of the publicly available studies finds that a pervasive lack of measurements makes it nearly impossible to know with confidence what the average methane leak rate is for the U.S. as a whole. More measurements, more reliable data, and better understanding of industry practices are needed.

It has been widely reported that shifting from coal to gas in electricity generation will provide a 50 percent reduction in greenhouse gas emissions. In reality, the extent of reduced global warming impact depends largely on three factors:

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The methane leak rate from the natural gas system;
How much time has passed after switching from coal to gas, because the potency of methane as a greenhouse gas is 102 times that of carbon dioxide (on a pound-for-pound basis) when first released into the atmosphere and decays to 72 times CO2 over 20 years and to 25 times CO2 over 100 years, and;
The rate at which coal electricity is replaced by gas electricity.

Our interactive graphic below incorporates all three factors, making it easy to visualize the greenhouse benefits of converting power generation from coal to natural gas for different assumptions of methane leak rates and coal-to-gas conversion rates while also considering methane’s greenhouse potency over time.

The Environmental Protection Agency (EPA) recently estimated methane leaks in the natural gas system at 1.5 percent. A 1.5 percent leak rate would achieve an immediate 50 percent reduction in greenhouse gas emissions, at the individual power plant level. However, EPA’s estimate contains significant uncertainty, and like all estimates available in the peer-reviewed literature, lacks sufficient real-world measurements to guide decision-making at the national level. We found that the ongoing shift from coal to gas in power generation in the U.S. is unlikely to provide the 50 percent reduction in greenhouse gas emissions typically attributed to it over the next three to four decades, unless gas leakage is maintained at the lowest estimated rates (1 to 1.5 percent) and the coal replacement rate is maintained at recent high levels (greater than 5 percent per year).

The climate benefits of natural gas are sensitive to small increases in leak rates. Assuming that natural gas replaces 2.5 percent of coal-fired power each year (the average over the past decade) even a relatively low overall leak rate of 2 percent would not achieve a 50 percent reduction in greenhouse gas emissions compared to the current fleet of coal-fired power plants, for over 100 years. If the leak rate were as high as 8 percent, there would be no climate benefit at all from switching to natural gas for more than 60 years.

To compute these estimates, we analyzed first the potential greenhouse gas benefits from replacing the electricity generated by a single coal power plant with electricity from natural gas instead. For an individual power plant, if the leak rate were 2 percent it would take 55 years to reach a 50 percent reduction in greenhouse impacts compared to continued coal use. If the leak rate is more than 6 percent of methane production, switching to natural gas provides zero global warming benefit for the first 5 years compared to continuing with coal. The switch achieves a modest 17 percent reduction in greenhouse gas emissions after 37 years (or by 2050, if the switch occurs in 2013). An 8 percent leak rate increases greenhouse gas emissions until 2050 compared with continued coal use, and produces only about 20 percent less climate pollution than continued coal use after 100 years of operation.

But unlike converting a single power plant from coal to natural gas, the U.S. cannot switch its entire fleet of coal-fired power plants to natural gas all at once. When substitution is analyzed across the entire fleet of coal-fired plants, the rate of adoption of natural gas is a critical factor in achieving greenhouse benefits. The rate of adoption is analyzed together with the powerful but declining potency of methane emissions over time. Each year, as a certain percentage of coal plants are converted to natural gas, a new wave of highly potent methane leaks into the atmosphere and then decreases in potency over time.

When the rate of adoption is included, the greenhouse gas benefits of switching to natural gas can be even more elusive. With a 2 percent methane leak rate, and an average annual conversion rate of electricity from coal to gas of 2.5 percent (a rate that would be supportable with new gas production projected by the U.S. Department of Energy) the reductions would be 29 percent by 2050 and 16 percent by 2030. If methane leakage is 5 percent of production, by 2050 the U.S. would reduce the global warming impact of its fleet of coal fired power plants by 12 percent. By 2030, the reductions would be just 5 percent. With an 8 percent leak rate, greenhouse gas emissions would be greater than with coal for more than 50 years before a benefit begins to be realized.

What is the natural gas leak rate in the U.S.? There are large differences among published estimates of leakage from the natural gas supply system, from less than 1 percent of methane production to as much as 8 percent. At the basin level, studies have reported methane leak rates as high as 17 percent. The EPA’s 2012 annual greenhouse gas emissions inventory estimate was 2.2 percent. Its 2013 inventory estimate made a large adjustment that reduced the estimate to 1.5 percent. The degree of methane leakage is uncertain, but it is likely to be reduced in the future since it also represents lost profits for gas companies. Nevertheless, our analysis indicates that the ongoing shift from coal to gas in power generation in the U.S. over the next three to four decades is unlikely to provide the 50 percent benefit that is typically attributed to such a shift.

Determining methane leakage is complicated by various uncertainties:

Large variability and uncertainty in industry practices at wellheads, including:

Whether methane that accompanies flowback of hydraulic fracking fluid during completion of shale gas wells is captured for sale, flared, or vented at the wellhead. Industry practices appear to vary widely.
Liquids unloading, which must be done multiple times per year at most conventional gas wells and at some shale gas wells. Gas entrained with the liquids may be vented to the atmosphere. There have been relatively few measurements of vented gas volumes, and estimating an average amount of methane emitted per unloading is difficult due to intrinsic variations from well to well.

Lack of sufficient production experience with shale gas wells:

There are orders of magnitude in variability of estimates of how much gas will ultimately be recovered from any given shale well. This makes it difficult to define an average lifetime production volume per well, which introduces uncertainty in estimating the percentage of gas leaked over the life of an average well.
The frequency with which a shale gas well must be re-fractured to maintain gas flow. This process, known as a well workover, can result in methane emissions. The quantity of emissions per workover is an additional uncertainty, as it depends on how workover gas flow is handled.

The leak integrity of the large and diverse gas distribution infrastructure:

Leakage measurements are challenging due to the large extent of the distribution system, including more than a million miles of distribution mains, more than 60 million service line connections, and thousands of metering and regulating stations operating under varying gas pressures and other conditions.
Recent measurements of elevated methane concentrations in the air above streets in Boston, San Francisco and Los Angeles strongly suggest distribution system leakages. Additional measurements are needed to estimate leak rates based on such measurements.

Making Sense of the Moore Tornado in a Climate Context

2013-05-21T19:14:00+00:00

The devastating tornado that ripped apart Moore, Okla., on Monday now joins the ranks of America’s strongest twisters on record, coming almost exactly two years after a similarly extreme and deadly tornado struck Joplin, Mo. In trying to make sense of the tragedy that unfolded in Moore, here are some of the things we know and don't know about tornadoes, and whether or how climate change may be influencing them now and into the future.

Tornadoes are no stranger to the U.S., which sees the majority of the world's tornadoes. The heart of "Tornado Alley" — where warm, moist air collides with cooler, drier air coming from the West — runs right through Moore, and the town was severely damaged by a tornado in 1999 as well as by less damaging twisters since.

Based on data from 1982-2011, Oklahoma City was the likeliest spot in the country for seeing severe thunderstorms on May 20. Tornado statistics show that the Oklahoma City metro area has had the most direct tornado hits of any American city, with at least 100 since 1890. That's according to the Storm Prediction Center in Norman, Okla., which is situated just down the road from Moore, and whose forecasters were forced to take shelter as the storm moved through.

Probability of severe thunderstorms within 25 miles of a location as averaged from 1982-2011. This shows the highest odds of severe weather on Monday were in Oklahoma.
Credit: Storm Prediction Center.

In recent years, tornado researchers and climate scientists have been trying to make advances in unlocking the secrets of what causes such monster storms, and how manmade global warming may already be affecting them now and in the future.

While the understanding of climate and tornadoes is progressing slowly, far more rapid gains have been made in the ability to forecast tornado outbreaks days in advance, and to detect and warn people when (or preferably before) tornadoes touch down. During the past two years, the National Weather Service upgraded its nationwide network of Doppler radars to take advantage of dual-polarization technology, which allowed forecasters in Oklahoma to provide an exceptional lead time of 16 minutes before the tornado struck Moore — far more than the average tornado warning lead time of 13 minutes.

Tornado data does not reveal any clear trends in tornado occurrence or deaths that would suggest a clear tie to global warming, at least not yet. A recent paper published in the Bulletin of the American Meteorological Society found that the occurrence of EF-1 and stronger tornadoes on the Enhanced Fujita Scale has shown no trend since 1954, which was the first year of near real-time data collection. Instead, an increase in tornado counts of EF-0 or stronger tornadoes has been attributed to an uptick in observations of very weak tornadoes. The Enhanced Fujita Scale measures tornado strength based on the extent and type of damage that they cause (no surface weather station has ever survived a direct tornado strike to take wind measurements from inside a twister).

Number of annual EF-3 or greater tornadoes from 1954 to 2012.
Credit: Storm Prediction Center.

It's difficult to tease out trends from historical tornado data, due to changing reporting practices, population growth, and the advent of advanced radar technology that has allowed meteorologists to spot more tornadoes now than ever before. It's thought that many tornadoes — particularly weaker ones — were missed in the early decades of recordkeeping, and construction methods have also changed with time. That's important since the strength of a tornado is determined by post-storm damage surveys.

“We have little confidence in the accuracy of trends in the meteorological occurrence of severe thunderstorms (including hail storms) and tornadoes,” according to a recent study published in the Bulletin of the American Meteorological Society.

Similarly, there is no evidence to indicate that EF-4 and EF-5 tornadoes — like the one that decimated a large swath of Moore — are becoming more frequent or severe. Such tornadoes are rare — they comprise less than 1 percent of the total number of tornadoes — yet they are the most reliable killers, accounting for 70 percent of tornado fatalities. The record annual number of EF-4 and EF-5 tornadoes occurred in 1974, when 36 such tornadoes scarred the landscape of the Midwest and Great Plains. Between 2000 and February of this year, there were 129 EF-4 and EF-5 tornadoes, according to a Storm Prediction Center database.

The number of tornadoes and tornado-related fatalities varies greatly from one year to the next, owing largely to natural climate and weather variability and where tornadoes happen to strike. (Given population growth, the chance that a tornado will strike a heavily populated area, such as Moore, is increasing.)

For example, the record 2011 tornado season, which featured a whopping 1,691 tornadoes — the second highest number on record — and 553 fatalities, was followed by one of the least active seasons on record the next year. According to the Storm Prediction Center, in 2012 there were just 939 tornadoes and 70 fatalities.

Large-scale climate patterns can influence tornado seasons. In 2011, there was a La Niña event in the tropical Pacific Ocean, which has been linked to active tornado seasons in the U.S. due to the way it influences the jet stream. In 2012, much of the country was hit with widespread drought, which dried up the severe thunderstorm season just as it dried up wheat fields across Tornado Alley. The drought continued into the first half of this year, before shrinking back to the west, and this tornado season got off to a very slow start. In fact, between 2012 and 2013, the U.S. had the longest-ever streak of days without a tornado fatality

Because historical tornado data is not considered very reliable or consistent, scientists have focused especially closely on how a warming climate is altering the balance of ingredients that go into producing a tornado.

The results of a computer-modeling study comparing the projected summer climate in 2072–2099 from 1962–1989. CAPE is predicted to rise enough to overwhelm a slight decrease in vertical wind shear, leading to an increase in severe thunderstorm days, particularly in the eastern states.
Credit: NASA Earth Observatory.

The predicted decrease in vertical wind shear from the same modeling study.
Credit: NASA Earth Observatory.

A key ingredient for producing tornadoes is a warm, moist, and unstable atmosphere. That means there needs to be high levels of humidity, and conditions in the middle to upper layers of the atmosphere need to encourage a rapidly rising motion of air. Such conditions were present on Monday, as demonstrated by the sky-high reading of one metric that meteorologists use to quantify atmospheric instability — known as “Convective Available Potential Energy,” or CAPE.

The CAPE reading in central Oklahoma was approaching 4,000 joules per kilogram on Monday. CAPE is a measure of the potential energy available for storms, and how much warm, moist and buoyant air is present in a given area. A CAPE value above 2,500 is considered to be an indication of extreme instability in the atmosphere, which means that if a trigger comes along for a storm, such as a cold front, storms could develop rapidly and quickly turn severe.

The high amount of instability on Monday helped thunderstorms explode along a slowly moving frontal boundary separating hot, humid air to the east from comparatively cooler and drier air to the west. This satellite loop shows the massive mushroom-like clouds, which reached heights of up to 60,000 feet above the surface, forming suddenly, as if lit by a fuse on Monday afternoon.

Satellite loop of the severe thunderstorms that spawned the Moore tornado. Credit: NOAA.

Climate studies show that atmospheric instability has already been increasing in some parts of the U.S., although not by a sufficient amount to make it distinguishable from natural variability, at least not yet. Computer-model projections of how instability may change in the future, though, show that this tornado ingredient is likely to increase because of warming surface temperatures and the addition of moisture in the air through evaporation. That increase in atmospheric instability could boost the number of days with severe thunderstorms in parts of the U.S.

One study, published in the Proceedings of the National Academy of Sciences in 2007, found that a doubling of greenhouse gases in the atmosphere would boost the number of severe thunderstorm days in parts of the U.S., particularly in the Southeast and along the East Coast. Some cities, including New York, could see twice as many potential severe thunderstorm days by the end of this century as they experience today.

Another necessary ingredient for tornadoes to form is atmospheric wind shear, which occurs when winds change in speed or direction with height. Wind shear was also present in abundance on Monday, which is why weather forecasters had highlighted that region as the most at risk for significant tornadoes.

In fact, some studies, including a paper published in the journal Atmospheric Research in April, have shown that wind shear is a more critical ingredient for strong tornadoes to occur than atmospheric instability, suggesting that a decrease in shear could limit the potential for the strongest tornadoes to occur in the future.

The author of that paper, Harold Brooks of the National Severe Storms Laboratory in Norman, Okla., gave a video interview at a tornado and climate research conference held at Columbia University earlier this year:

Credit: IRI.

While a warmer climate is likely to feature more opportunities for thunderstorms to form, studies also show a lessening of atmospheric wind shear, which would suggest a decrease in the potential for tornadoes to form. How these two trends play out — one increasing the odds of tornadoes, the other reducing them — is a subject of active scientific research.

A fact sheet from the National Oceanic and Atmospheric Administration on tornadoes and climate change describes the counteracting trends of decreasing shear and increasing instability in a warming world as a "tug of war."

One inference from the research to date is that given the likely abundance of instability in coming decades, when adequate wind shear to produce tornadoes is also present, tornado outbreaks could be even more extensive than they are today, although by how much is a question yet to be addressed. Advances in computer modeling will may soon enable scientists to better simulate small-scale events such as tornadoes, and the conditions that trigger them.

The bottom line? So far, there’s simply not enough information to say anything definitive about the future of tornadoes under climate change. But every thunderstorm, and every tornado, now takes place in a warmer, wetter atmosphere due to the increasing concentration of greenhouse gases in the atmosphere.

Widespread Greenland Melting A Sign of Things to Come

2013-05-21T16:45:12+00:00

When 97 percent of Greenland’s ice experienced at least some melting in July 2012, scientists wondered if it was a one-time phenomenon. Now a new study in Geophysical Research Letters indicates it is a sign of things to come and by 2025, there is a 50-50 chance of it happening annually.

It’s not clear what the effects of such melting will be: the majority of Greenland’s ice loss, which has accelerated significantly over the past decade, comes from glaciers shedding more ice into the sea, and moving faster toward the sea, not from melting snow and ice at higher elevations of the ice sheet.

Extent of surface melt over Greenland’s ice sheet on July 8, 2012 (left) and July 12, 2012. In just a few days, the melting had dramatically accelerated and an estimated 97 percent of the ice sheet surface had thawed.
Credit: Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory

Nevertheless, such widespread melting indicates an overall warming in the region that could threaten the ice more generally, adding significantly to the threat of sea level rise.

The 2025 projection is based on two factors, according to lead author Dan McGrath, a glaciologist at the University of Colorado, Boulder. The first is a series of temperature measurements going back to 1950 at the Summit research station, at the highest — and on average, the coldest — point on the Greenland ice sheet. The mercury has been rising more or less steadily there for that entire time, with the fastest increase, of about .22° F per year, coming since 1992. “That’s six times faster than the global average,” McGrath said in an interview.

The highest parts of the ice sheet still remain below the freezing mark virtually all the time, but when unusual weather conditions set in — an especially warm air mass, or as in the case of the 2012 melting, an influx of clouds just thin enough to let sunlight through but thick enough to block heat from escaping — the thermometer can sneak above 32°F. “Only an hour above freezing is enough to start the surface melting,” McGrath said.

Another factor that went into the analysis involved what’s known as the equilibrium line — the altitude where the snow is neither piling up year to year nor shrinking. Over the past 20 years or so, that transition zone has been gradually moving up the ice sheet by about 115 feet every year, on average— another indication that temperatures on the frozen island are warming.

Greenland cumulative melt days. Jan. 1 - May 20, 2013.
Credit: NSIDC

It was this second effect that led McGrath and his colleagues to launch their study. “When our research camp was established, it was put as close as possible to the equilibrium line,” McGrath said. “If they put it any lower, it would melt out every year, and if it was higher, it could get buried in snow.”

But when the team returned for the summer season in 2009, he said the surface had melted so much that “it was falling apart. It looked like someone had dropped a bomb on it.”

They relocated the camp, and things were fine in 2010, but the following summer it had melted out again. “That led us to look at things in more depth,” he said.

The findings broadly agree with earlier research by other groups. “This is clearly an interesting paper, although I think it’s dangerous to pinpoint such a specific date as 2025,” said Marco Tedesco, a glaciologist at City University of New York, who produced some of that research.

To Tedesco, there’s too little emphasis on how Greenland’s ice would respond to a variety of scenarios for emissions of greenhouse gases, the primary reason for the planet’s overall warming over the past half-century.

Tedesco also felt that the new paper didn’t look hard enough at some of the feedback mechanisms between the ice sheet and the atmosphere that could arise as melting ice gives rise to more clouds, for example.

Nevertheless, he agreed, the overall message is entirely consistent with what others have found: Greenland’s ice is under assault by rising temperatures, and whether or not 2025 will represent a milestone, the consequences over coming decades could be catastrophic.

Warming Causing Rockies, Everest to Lose Ice and Snow

2013-05-20T12:30:32+00:00

By Tim Radford, Climate News Network

LONDON – Around 20 percent of the snow cover in North America’s greatest mountain range has been lost – because of warmer springs in the last three decades.

Scientists from the American Geophysical Union and the U.S. Geological Survey report that they had established a pattern of snowfall in the northern and southern Rockies: when the snowpack was large in the northern Rockies, it might be correspondingly meager in the southern mountains and vice versa.

But since the 1980s, snowpack declines have occurred simultaneously along the entire length of the Rocky Mountains, with unusually severe declines in the north.

Researchers blame both natural variation like El Niño and La Niña and global warming from human activity for the loss of snow and ice.
Credit: Pavel Novak

Now research has begun to establish the cause. Researchers write in Geophysical Research Letters that, using monthly data collected from 1895 to 2011, they have been able to tease apart the different influences of winter temperatures, spring warming and overall precipitation on the April volume of the snowpack.

“Snow deficits were consistent throughout the Rockies due to lack of precipitation during the cool seasons during the 1930s – coinciding with the Dust Bowl era.”

“From 1980 on, warmer spring temperatures melted snowpack throughout the Rockies early, regardless of winter precipitation,” said Greg Pederson of the Northern Rocky Mountain Science Center in Bozeman, Montana.

“The model in turn shows temperature as the major driving factor in snowpack declines over the past 30 years.”

Runoff from the Rocky Mountain snows accounts for 60 to 80 percent of the annual water supply for more than 70 million people in the western U.S. The timing of snowmelt affects the levels of water available for crop irrigation and hydro-electric power. It can also influence the risk of regional floods and bush fires.

The researchers blame both natural variation – the influence of cyclic Pacific Ocean phenomena such as El Niño and La Niña, for example – and global warming from human activity for the change.

Snowline heads uphill

“Regardless of the ultimate causes, continuation of present snowpack trends in the Rocky Mountains will pose difficult challenges for watershed management and conventional water planning in the American West,” said co-author Julio Betancourt.

Meanwhile, at the American Geophysical Union’s meeting in Cancun, Mexico, researchers report that the world’s highest peak, Mt. Everest, is beginning to lose its snow and ice.

They report, after studies of satellite imagery of the mountain and the Sagarmatha National Park, that the Everest region in the Himalayas has been warming, and snow precipitation declining, for the last 20 years.

Everest glaciers have shrunk by 13 percent in the last 50 years and the snowline has moved 180 meters uphill. As the glaciers dwindle, the rocks and debris they carry are being exposed: the debris-covered sections of the glaciers have increased by 17 percent since the 1960s.

Once again, the researchers suspect that human-induced climate change may be responsible: this connection however is much harder to establish. But the majority of glaciers in the region are retreating at an ever-faster rate.

“The Himalayan glaciers and ice caps are considered a water tower for Asia, since they store and supply water downstream during the dry season,” said the scientist Sudeep Thakuri. “Downstream populations are dependent on melt water for agriculture, drinking and power production.

Tim Radford is a reporter for Climate News Network. Climate News Network is a news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.

Study Projects Steep Increase in NYC Heat-Related Deaths

2013-05-19T19:15:12+00:00

An increasing number of New Yorkers are likely to die from heat-related causes as global warming causes more extreme heat events, according to a new study released Sunday.

The study found that heat-related mortality may rise 20 percent by the 2020s, and in some worst-case scenarios, it could increase by 90 percent or more by the 2080s, and the net temperature-related mortality, which includes the drop in deaths related to cold weather, could jump by a third compared to current levels.

Leading causes of weather-related fatalities in the U.S.
Credit: NOAA.

The study, published in the journal Nature Climate Change, was produced by Tiantian Li of the Chinese Center for Disease Control and Prevention, and Radley Horton and Patrick Kinney of Columbia University. The study is the most thorough examination to date of how global warming is likely to alter monthly temperature-related mortality in a major metropolitan area, at a time when the world is becoming increasingly urbanized and mayors are pursuing climate adaptation projects in the U.S. and abroad.

With global-average surface temperatures increasing in response to manmade emissions of greenhouse gases, the world has already been seeing an uptick in the frequency and severity of deadly extreme heat events, and a decrease in cold-weather extremes.

Some other studies have claimed that as heat wave-related deaths increase, they will be offset by a reduction in cold weather-related deaths, keeping the net change in mortality low or possibly even resulting in fewer temperature-related deaths per year. This study, however, finds the opposite to be true.

Extreme heat is already the No. 1 weather-related killer in the U.S., killing an average of 117 people per year during the 2003-2012 period. Hot temperatures can contribute to cardiovascular disease, aggravate respiratory illness, and cause heat stroke, among other life-threatening conditions.

Even a small amount of global warming can have a large effect on weather extremes, as recent studies have shown.

In the study, each of the 32 projections from 16 different computer models all yielded an increase in net annual temperature-related deaths, mainly due to the increase in heat-related illnesses. The researchers found a net annual increase in mean temperature-related mortality in New York City of between 5.3 percent and 6.2 percent by the 2020s, depending on the emissions scenario used, and between a 15.5 and 31.0 percent increase by the 2080s.

Cities tend to be warmer than surrounding areas due to the urban heat island effect, since buildings and pavement absorb more incoming solar radiation during the day, and give off heat more slowly at night. Between 1901 and 2000, the average temperature at New York’s Central Park rose by about 3.6°F, which was faster than the national average. Last year was New York’s hottest on record, with summer temperatures that exceeded 100ºF on several occasions.

According to a study published in 2012 in the Proceedings of the National Academy of Sciences, during the period from 1951-1980, extremely hot summers covered just 1 percent of Earth’s land area. That had risen to 10 percent of the Earth’s land area by the period from 1981-2010, and even higher during the 2006-2010 period.

In other words, the study found that the odds of such extreme summers were about 1-in-300 during the 1951-1980 timeframe, but that had increased to nearly 1-in-10 by 1981-2010.

A heat wave in Chicago in 1995 killed hundreds, and the 2003 European heat wave, which studies have shown was made more likely by manmade global warming, killed an estimated 40,000 people. More recently, a 2010 heat wave in western Russia also killed thousands and set all-time record high temperatures for the region.

The larger increase in heat-related deaths compared to the drop in cold-related deaths foreseen by the new study makes sense when one considers that what are typically counted as cold weather-related deaths may not in fact be due to the cold.

According to Patrick Kinney, who directs Columbia’s Climate and Health Program at the Mailman School of Public Health and co-authored the new study, previous research mistakenly attributed spikes in cold season deaths to temperature, rather than illnesses such as influenza, which tend to reach their peak during the winter. These diseases will continue to take their toll during the winter.

“In reality, winter respiratory and related cardiovascular deaths won’t go away at warmer temperatures,” Kinney said in an email. “We see evidence of that when we look at cities that already have warmer temperatures — such as Honolulu — they still have just as big of a winter increase in deaths as much colder places, like Detroit.”

The study found the biggest percentage changes in heat-related mortality would occur during the months of May and September, as those months would begin to see extreme heat events that typically only occur in the June-through-August period.

The study assumes that the increase in temperatures on the hottest and coldest days will shift in lock step with the increase in typical summer or winter temperatures. However, other research has shown that this is not necessarily the case, with larger shifts in the most extreme temperatures taking place in response to a generally warming climate. That may mean that the study actually underestimates future temperature-related mortality.

On the other hand, the study does not take into account the impacts of adaptation measures, such as expanding the use of air conditioning, nor does it address possible changes in humidity and air quality, which would also influence mortality rates.

“One critical question is the extent to which as a society we may be able to better adapt to heat events in the future,” said co-author Radley Horton of Columbia. He cited New York’s efforts to plant trees, make rooftops more reflective to reduce the urban heat island effect, and increase access to air conditioned-cooling centers, as examples of steps that have already been taken to minimize heat-related illness.

“Around the U.S., will such adaptation strategies — which are already yielding benefits — be able to keep pace with rising temperatures?” Horton said in an email, “Or will potential non-linear surprises, such as small increases in summer temperature producing large impacts on public health and supporting infrastructure, predominate? Many Americans, of course, do not currently have easy access to air conditioning.”

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Rising Temperatures in Europe Leave Ducks Grounded

2013-05-19T12:30:05+00:00

By Kieran Cooke. Climate News Network

LONDON – Most birds are acutely sensitive to changes in temperature. Scientists now say that changes in climate and warmer temperatures in parts of Europe have resulted in the migration patterns of certain birds being radically altered.

A study looking at the migration patterns of three species of duck – the goldeneye, goosander and tufted duck – has found there has been a sharp decrease in the number of birds migrating south.

Birds like this female goosander are migrating much less than before due to rising temperature in parts of northern Europe.
Credit: Tony Hisgett

The study, published in Global Change Biology, examined the migration patterns of the three duck species over the 1980 to 2010 period. It found that mid-winter numbers of individual ducks at the southern edge of the species’ normal distribution range – in France, Ireland and Switzerland – had dropped by nearly 120,000.

Meanwhile mid-winter numbers of the species in Finland and Sweden – in areas where the ducks breed in summer – had increased by a similar amount.

Chas Holt of the British Trust for Ornithology, a co-author of the study, says ornithologists in Finland were the first to notice that numbers of ducks were no longer flying south in winter.

“It’s essentially a fairly gradual shift in behavior, but it’s clear that a rise in temperatures in regions of Finland and Sweden means the ducks no longer fly south but stay closer to their summer breeding grounds all year round,” Holt told Climate News Network.

Early winter temperatures in the ducks’ breeding grounds in Finland were found to have increased by 3.8°C over the 1980 to 2010 period.

Food under pressure

“There is a sharp correlation between these shifts in the range of migration and the rise in temperatures,” says Holt.

Scientists say that if increasing numbers of birds do not migrate, there’s a risk that habitats will come under increasing pressure as food supplies dwindle.
Credit: flickr/Tony Sutton

“Three decades ago there would have been no open water for the ducks in winter in these north-eastern areas of their normal range. Now there is – and the ducks don’t have to move so much from their breeding grounds.”

Scientists say that if increasing numbers of birds do not migrate, there’s a risk that habitats will come under increasing pressure as food supplies dwindle.

They also say that while many bird species have shown an ability to adapt to changes in temperature, many may not be able to alter their behavior fast enough if temperatures fluctuate rapidly.

“What happens if there is an exceptionally cold winter in the midst of a period of relatively mild ones?” asks Holt. “Can birds such as these ducks adapt fast enough and resume their old migration patterns?”

“The whole issue has to be placed in context. We are seeing declines everywhere in various bird species. These changes in migration patterns also mean we have to adapt our conservation strategies as new bird wintering areas are established.”

Kieran Cooke is a co-editor for Climate News Network. Climate News Network is a news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.

Clouds ‘Cool Earth Less Than Once Thought’

2013-05-18T14:01:21+00:00

By Paul Brown, Climate News Network

LONDON – Extra cloud cover caused by emissions of industrial pollutants is known to reduce the effects of global warming, but its impact in reducing temperatures has been over-estimated in the climate models, new research has found.

This is particularly significant for China and India, because it has been believed that these two giant countries would be partly shielded from the effects of climate change by their appalling industrial pollution. The Max Planck Institute for Chemistry in Germany believes this potential cooling effect has been exaggerated.

The Institute’s study looked at the behavior of sulphate particles in the air created by the reaction of oxygen with sulphur dioxide released from factory chimneys and other sources of pollution.

Extra cloud cover caused by emissions of industrial pollutants is known to reduce the effects of global warming, but its impact in reducing temperatures has been overestimated in the climate models.
Credit: Ave Maria Moistlik

In humid conditions the sulphates attract water droplets and form clouds. This increase in the cloud cover reflects more sunlight back into space and so cools the earth.

The Max Planck researchers went to study a cloud formed at the top of a mountain, taking samples at various times to see how the sulphates reacted progressively. What was crucial was how the sulphates were formed in the first place.

Current climate models assume that hydrogen peroxide and ozone have a large role in creating the sulphates, but the new research shows that the catalysts for the chemical reaction are more likely to be metal ions like iron, manganese, titanium or chromium.

The key factor is that all of these are heavier than hydrogen peroxide and ozone, and because of this are more likely to fall out of the cloud through the pull of gravity, thus considerably reducing the cooling effect of the original pollution.

Less time aloft

Eliza Harris and Bärbel Sinha, with a number of other scientists, captured the air samples and examined the isotopes in a mass spectrometer.

Harris, who was recently awarded the Dieter Rampacher Prize as the youngest doctoral candidate of the Max Planck Society, said: “The relative reaction rates of isotopes are like fingerprints, which tell us how the sulphate was formed from the sulphur dioxide.”

“As my colleagues and I compared the basic assumptions of climate models with my results we were very surprised, because only one of twelve models considers the role of transition metal ions in the formation of sulphate,” said Harris, who is now working at the Massachusetts Institute of Technology (MIT) in the U.S.

Because of the extra size of the sulphates and hence their greater weight, compared with the previous assumptions, she believes that climate models have over-estimated the cooling effect of the sulphate aerosols by assuming they would stay airborne longer.

So far the findings have not been factored into calculations on the regional effect of climate change. Harris says that in Europe, where pollution from industrial processes is already on the decline, the change in the calculations on warming would be relatively small.

However, in the growing industrial giants like India and China, where coal-fired power stations and other forms of industrial pollution are throwing out sulphur dioxide at an ever-greater rate, then the effect could be considerable. Further research on this is continuing.

Paul Brown is a joint editor at Climate News Network. Climate News Network is a news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.

Tornadoes Resume; Drought Divides; Fish on the Move

2013-05-18T12:30:17+00:00

Slideshow

Weather Service to Add Major Might to Computing Power

2013-05-17T15:44:47+00:00

After coming under fire for falling behind the capabilities of other nations, the National Weather Service (NWS) is setting out to make an unprecedented increase in its computing power over the next several years, the agency announced this week. The computing boost will triple a key measure of the agency's main weather model, and could yield major improvements to its weather forecasting and warnings capabilities.

The ECMWF model consistently forecast that Hurricane Sandy would make landfall in the Mid-Atlantic region, starting a week in advance.
Credit: Weatherbell.com.

The program is made possible by recent funding from Congress contained in the Hurricane Sandy relief legislation, which was signed into law in January. The NWS plans to use $25 million of the $48 million provided to it in the Sandy supplemental bill, along with funds that are called for in President Obama’s fiscal year 2014 budget proposal, to bring about "unprecedented" computing upgrades — going from an operational computing capacity of 213 peak teraflops at the end of the current fiscal year, to 1,950 peak teraflops by the end of fiscal year 2015, according to NWS Director Louis Uccellini. A teraflop is a measure of how many calculations a computer can make per second, and indicates that a computer can make one trillion “floating point calculations” in just one second. In other words, the agency doesn’t run weather models on your typical personal computer.

“To go from 213 to 1,950 terraflops is the largest increase in computing capacity that we’ve ever had,” Uccellini told Climate Central in an interview. The NWS expects the European Center for Medium Range Weather Forecasts (ECMWF), which currently has a forecast model that is considered to be the most reliable, especially in the 5- to 9-day timeframe, to have an operational capacity of just 554 teraflops by the end of Fiscal Year 2015.

Uccellini said the high-speed computing improvements will help the agency to improve the accuracy of its Global Forecast System (GFS) model by running it at a higher resolution, which will allow it to better capture small-scale weather features — such as thunderstorms — that can affect the accuracy of a forecast. He also said the upgrades, which will be akin to shifting a supercomputer from first gear into overdrive, will enable the agency to put into operation higher-resolution, short-range computer models and observation systems. Those models could provide more accurate predictions for severe thunderstorms and hurricane forecasts.

Uccellini said that the agency has high-resolution computer models that have been developed and tested already, but they have not been implemented because of current computing limits. “We just didn’t have the computing capacity to put them in,” Uccellini said.

The raw power of a computer model is by no means the only key to an accurate weather forecast, and the NWS still needs to improve the ways its models ingest the massive amounts of weather data coming from surface weather stations, weather balloons, aircraft observations, satellites, and other sources. However, faster computers do allow models to be run at higher resolution, meaning that instead of dividing the world into 55-kilometer grid boxes as the GFS model now does, the same model can be run with a horizontal spacing of 10 kilometers.

The GFS model is the main American forecasting model out to 16 days in advance.
Credit: NOAA.

That is important because many weather phenomena, such as thunderstorms, are small in diameter and aren't captured by coarse-resolution models.

The investments will also put the agency on a trajectory to eclipse other forecasting centers that currently have more technological resources at their disposal, and more accurate computer models.

The NWS had come under fire during the past year for the shortcomings of its GFS model compared to the ECMWF. The European model accurately forecast the path of Hurricane Sandy one week in advance, at a time when the GFS model was still showing that the storm would curve harmlessly out to sea away from the East Coast. Similarly, the European model also offered more accurate forecast guidance at longer lead times for some high-impact northeast snowstorms last winter.

Currently, the GFS model is run at a reduced resolution in the extended period beyond seven days, whereas the European model has a higher resolution out to 16 days in advance.

“They capture these storm systems further in advance with that high resolution model,” Uccellini said of the ECMWF. He said the boost in the NWS computing power “will significantly improve the reliability of our forecasts and bring us on par with the European Center.”

If the computing upgrades result in more accurate weather forecasts, as the NWS expects, it could reduce economic losses from weather events. A 2011 study found that routine weather variability alone affects the American economy to the tune of approximately $485 billion each year, not including the billions that are lost when major storms strike heavily populated areas.

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The U.S.: A Nation Divided By Drought

2013-05-17T12:42:00+00:00

What was once a coast-to-coast drought now divides the U.S. into two distinct pieces, pitting those that have water in the Midwest vs. the have-nots in the West. One of those regions is in for a long, hot, dry, and potentially smoky summer. (Hint: It's not the Midwest.)

This national drought picture comes from two new reports released on Thursday from the National Oceanic and Atmospheric and Atmospheric Administration (NOAA), which updated the weekly U.S. Drought Monitor that shows weekly drought conditions across the country, and the Seasonal Drought Outlook, which provides a three-month forecast that is based on current conditions and the expected precipitation and temperatures for June, July and August.

“Drought continues to plague large areas of the U.S.,” said Jake Crouch, climatologist at NOAA’s National Climatic Data Center, on a conference call with reporters. “There has been an expansion of drought westward, with those drought conditions in the Midwest all but disappearing.”

The nine-state area of the Midwest that stretches from Kentucky to Michigan and Missouri to Minnesota has seen a dramatic reduction in drought since early March, aided by an usual weather pattern that brought repeated rain and snowstorms during the spring.

Since March 5, the percentage of the Midwest in “moderate drought” or worse has declined from 45 percent to 10 percent, and the areas of extreme and severe drought have almost all been eliminated. Michigan and Wisconsin both saw their wettest January to April period on record. Duluth, Minn., picked up 50.8 inches of snow in April, breaking its all-time snowfall record for a single month, and shattering its record for the snowiest April.

Total precipitation across the West so far this year (left) along with the percent of average precipitation for the same period.
Click image to enlarge. Credit: NOAA.

The wet Midwest has contrasted sharply with the dryness in the West, where California saw its driest January-to-April period on record.

According to the drought outlook, the Midwest is expected to remain drought-free this summer. Much of the High Plains may also see some improvement, as those states typically receive the bulk of their precipitation during this time of year.

The U.S. as a whole has been drier than average this year to date. Most of the West, Southwest, and New England are all facing 90-day precipitation deficits, which have dragged down the national average.

The latest seasonal drought outlook.
Credit: NOAA.

The most recent Drought Monitor shows that nearly all of the land west of Iowa and south of Montana is still under some form of drought. More than 78 percent of Wyoming is still under severe drought or worse.

Things are worse in Nebraska, where 70 percent of the state is under at least extreme drought conditions. And in New Mexico, more than 81 percent of the state is under extreme drought or worse, with 44 percent of the state under exceptional drought.

Low snowpack in the Northern Rockies allowed parts of southern Montana to slide into “extreme” drought, and “exceptional” drought continued to expand in the areas that encompass the intersection of Colorado, New Mexico, Kansas and Texas.

The dry conditions across the West have elevated the risk for wildfires. NOAA has issued a hazard outlook for wildfires in eastern New Mexico for the period between May 18-22. Last year was one of the worst wildfire seasons on record. According to the National Interagency Fire Center, wildfires in 2012 burned more than 9 million acres of federal land, making it the third-largest burn year since 1960. As the world continues to warm from climate change, wildfires across the West are expected to become more frequent and severe.

The Midwest had a very wet April, which effectively ended the drought in some areas.
Credit: NOAA.

The seasonal drought outlook calls for the drought in the West to continue to expand and intensify. The three-month forecast calls for above-average temperatures and below-average precipitation over most of the existing drought area. The end-of-season snowpack in the West is spread unevenly — there is an average amount of snow in place over small parts of Colorado and Washington State, but most of the snow cover is much thinner than average, if it exists at all, in Arizona and New Mexico.

“This is the part of year when snowmelt becomes an important factor, and many of those locations have dismal snowpack,” said Crouch. “Arizona and New Mexico have below-average water in their reservoirs at this time, and snowmelt will not replenish those numbers.”

As the drought drags on, its impacts are being felt more acutely on water supplies. According to the Southern Plains Regional Drought Outlook, three of the four largest reservoirs in New Mexico are at less than 15 percent of storage capacity. The largest, Elephant Butte, is at only 11 percent of capacity. Across the state, streamflow forecasts are less than half of normal.

Texas is expected to enter the summer with its fewest amount of stored water in at least 25 years, with statewide reservoir capacity at just 66 percent, or 12 percent less than at the same time last year, NOAA reported.

In the Southwest, some relief might come from the summer monsoons that blow off the Pacific Ocean in mid-July, but experimental outlooks of monsoon-related precipitation show below-average precipitation likely in much of northern and eastern New Mexico, with more abundant rainfall possible beginning in mid-summer in the southwestern part of the state.

Study: 97 percent Agreement on Manmade Global Warming

2013-05-16T19:37:16+00:00

By Angela Fritz, Weather Underground

The scientific agreement that climate change is happening, and that it's caused by human activity, is significant and growing, according to a new study published Thursday.

The research, which is the most comprehensive analysis of climate research to date, finds that 97.1 percent of the studies published between 1991 to 2011 that expressed a position on manmade climate change agreed that it was happening, and that it was due to human activity.

Click image to enlarge.

The study looked at peer reviewed research that mentioned climate change or global warming. Peer review is the way that scientific journals approve research papers that are submitted. In peer review, group of scientists that weren't involved in the study, but who are experts in the field, look at the research being submitted and have approved that it meets scientific process standards, and the standards of that journal.

In 2011, 521 of those peer reviewed papers agreed that climate change is real, and that human activity is the cause. Nine papers in 2011 disagreed.

John Cook, founder of skepticalscience.com and the lead author on the study, said the motivation for the analysis was the importance of scientific consensus in shaping public opinion, and therefore policy. "When people understand that climate scientists agree on human-caused global warming, they're more likely to support climate policy," Cook said. "But when the public are asked how many climate scientists agree that humans are causing global warming, the average answer is around 50 percent."

This "consensus gap" is what Cook and the research team is trying to close. "Raising awareness of the scientific consensus is a key step towards meaningful climate action," Cook said.

This study is not the first to examine the overwhelming agreement among climate scientists. Surveys of actively publishing climate scientists as well as analyses of climate change papers have shown similar results.

In 2004 Naomi Oreskes, Professor of History and Science Studies at the University of California San Diego, published what many scientists consider the seminal study on climate change consensus. She also co-authored the book Merchants of Doubt, which identifies and examines the similarities between today's climate change conversation and previous controversies over tobacco smoking, acid rain, and the hole in the ozone layer.

Oreskes believes that the public isn't aware of the consensus because of deliberate efforts to cause confusion. "There has been a systematic attempt to create the impression that scientists did not have a consensus, as part of a broader strategy to prevent federal government action," Oreskes said. "The public have been confused because people have been trying to confuse us."

The study published Thursday is the first to take so many papers and authors into account. Doing a search on the popular science article website Web of Science for "climate change" or "global warming" produces over 12,000 results. Of these, 4,014 papers were identified to state a position on climate change. Among those, 3,896, or 97.1 percent endorsed the consensus that climate change was happening and that it was caused by human activity.

In an interesting result, Cook and his team found that over time, scientists tend to express a position on climate change less and less in their research papers. This is likely a result of consensus — that if a scientific conclusion has been reached, there's no need to continue to state that conclusion in new research. "Scientists tend to take the consensus for granted," says Cook, "perhaps not realizing that the public still think it's a 50:50 debate."

Reprinted with permission from Weather Underground.

Smaller Glaciers Boost Sea Level as Much as the Giants

2013-05-16T18:05:23+00:00

As the planet warms under the influence of rising greenhouse gases, and melting ice drives sea level higher, scientists have focused mostly on changes in the vast ice sheets that cover Greenland and Antarctica. If either one melts substantially or slides into the ocean, the results would be catastrophic.

But there’s another ice reserve to worry about: the many thousands of smaller glaciers unconnected to continental-scale ice sheets. They’re melting, too, and a new report in Science shows that between 2003 and 2009, they dumped about 260 billion tons of meltwater into the ocean annually, contributing about 0.7 millimeters per year to sea level rise, just as much as the Greenland and Antarctic ice sheets.

Tongue of a glacier on the northeast coast of Baffin Island, Nunavut, Canada.
Credit: Ansgar Walk via Wikimedia Commons

“These glaciers are typically ignored because they’re so small in comparison,” said lead author Alex Gardner, of Clark University, in an interview,

The new number doesn’t change scientists’ estimates of where sea level is headed by the end of this century — or at least, not yet. “Our study has implications for future projections, but we will not entirely know what those implications are until our new estimates are ingested into the models,” Gardner said.

Most projections currently show an increase of about 3 feet, on average, by 2100, compared with the 8 inches of sea level rise planet has seen since 1900. Given the damage wrought by storm surges from Hurricane Isaac and Hurricane Sandy in 2012 — surges that higher seas made worse than they would have been a century ago — another 3 feet of ocean height could prove nothing short of catastrophic.

There’s still a fair amount of uncertainty in these projections, however. Part of that is because glaciologists don’t fully understand the dynamics of how glaciers that are tied to the great ice sheets will speed up in their flow to the sea as the planet warms. But part of the uncertainty is also due to conflicting estimates of ice loss in smaller glaciers.

Measurements taken by satellites, including GRACE and IceSat, show about half as much ice loss as glaciologists had come up with by going out into the field and taking measurements on the ground. “So we decided to embark on a study that brought together GRACE people, IceSat people, and field people to try and reconcile those differences,” Gardner said.

Among those differences were that various studies covered different areas, over different time periods, and with very different resolution (GRACE, for example, can see average changes in ice mass over large areas; IceSat had much better resolution but poorer global coverage).

By focusing on places where all three sets of observations overlapped in space and time, the 16 scientists who co-authored the study managed to calibrate them all to each other, and in the end, J. Graham Cogley, of Trent University in Canada, told Science, “I think there really was a consensus.”

That consensus, perhaps unsurprisingly, came in between the high estimates of ice loss from ground-based studies and the lowball numbers from the satellites. “We can finally say with strong confidence what the contribution of glaciers to sea level rise actually was between 2003 and 2009,” Gardner said.

And that in turn will help refine future projections.

“If we can’t understand the processes that determine what’s going on today, we can’t say anything meaningful about what lies ahead,” Gardner said. “Now that we’ve been able to bean-count the contributions of glaciers; we’re getting closer to balancing the sea level budget.”

Editor's Note: This article has been updated to indicate that the amount of sea level rise contributed by small glaciers was 0.7 mm/yr, not 7 mm/yr as originally indicated.

As Oceans Warm, Fish Are Finding New ZIP Codes

2013-05-15T19:00:57+00:00

Fish species are shifting their ranges around the world in response to warming oceans, a trend that could have significant economic ramifications globally, a new study found.

The study, published Wednesday in the journal Nature, employs a novel index that creates a fish thermometer of sorts, teasing out evidence of population shifts from fishery catch records during the past four decades. The study is the first to detect climate change-related shifts in the range of fish species on a global scale. In doing so, it provides another line of evidence showing the far-reaching impacts of global warming.

The 2012 sea-surface temperature anomaly in the North Atlantic compared to the mean of the past 100 years across the North Atlantic basin.
Click image to enlarge. Credit: Northeast Fisheries Science Center.

“We knew that oceans have warmed up in the last four decades, but we didn’t know how it’s affecting fisheries catch globally,” said study co-author William W.L. Cheung of the University of British Columbia in Vancouver in an interview.

Each cold-blooded fish species has a particular temperature range in which it thrives. If water temperatures depart from that range, they may experience reduced growth and reproduction, ultimately reducing their numbers in a particular area and changing the species' distribution.

Climate change-driven shifts in fisheries pose the biggest threat to livelihoods in developing countries, especially in the tropics, where adaptation capacity of both people and fish themselves are more limited, Cheung said. One adaptation measure that may need to be looked at is for fishery managers, such as the National Marine Fisheries Service in the U.S., to adjust fishing seasons and allowable catches based on observed population shifts.

With climate change predicted to accelerate in coming decades due to the rising amount of greenhouse gases in the atmosphere, even faster shifts in fish populations are possible, which could even lead to disputes between countries if commercially valuable fish shift out of one country’s waters and into another's, according to Boris Worm, a marine biologist at Dalhousie Univeristy in Nova Scotia who was not involved in the Nature study.

“This is an independent indication that climate change is real and has been real for a long time,” he said of the study. Worm cited recent shifts in cod, hake, lobster, and sardine populations off of Nova Scotia, with the southern end of species’ range dropping off as they move north.

“Things are changing very rapidly,” Worm said. “It’s warming fast and the fish are moving fast.”

By examining records of fisheries catches in 52 large marine ecosystems — from the hake caught off New England and northeastern Canada to the halibut haul off Alaska — researchers in Canada and at the University of Tasmania in Australia developed an index relating the annual fish catch of a species to its typical temperature preference. The index, known as the “mean temperature of the catch,” increased worldwide during the past four decades.

The Atlantic Cod is a species that has shifted its range northward during the past several decades.
Credit: Wikimedia Commons.

After accounting for the effects of fishing practices and large-scale oceanographic variability, Cheung and his colleagues found a statistically significant link between changes in the fisheries temperature index and increasing sea surface temperatures.

During the period from 1970 to 2006, the study found that the global mean temperature of the catch increased by a rate of 0.19°C, or 0.34°F per decade, and in non-tropical areas, the rate of increase was even higher, at 0.23°C, or 0.41°F per decade.

In tropical areas, there was an initial increase as subtropical species moved to cooler waters, but that increase leveled off since what were left are species that can only thrive in very warm water. Tropical fisheries are especially vulnerable to global warming, the study found, since species there tend to have a relatively narrow band of temperature tolerance and there is a limited supply of species that can move in to take their place and tolerate higher temperatures.

The study follows recent observations of an increase in warm-water species in several fisheries. During 2012, for example, water temperatures off the New England coast hit an all-time high, and shifts were observed in the distribution of Atlantic cod. A 2009 study found that about half of 36 fish stocks in the Northwest Atlantic Ocean were shifting northward over the past four decades, with some stocks exiting U.S. waters entirely.

“In high latitude regions we find, as expected, fisheries catch being increasingly dominated by warm-water species,” Cheung said.

On average, sea-surface temperatures are increasing by more than 1.8°F per decade, although there are regional variations, with some regions cooling due to changing ocean currents, and some warming four times faster than the global average, Cheung said.

Panel Finds Flaws with NWS Guidance on Sandy’s Surge

2013-05-15T17:31:41+00:00

The National Oceanic and Atmospheric Administration (NOAA) released its final review of the agency’s performance during Hurricane Sandy, finding that while the agency provided accurate forecasts of the storm’s path and strength well ahead of time, there were many shortcomings, including confusing and poorly timed guidance on the expected storm surge.

Pieces of the boardwalk float in sections through the flooded streets of Atlantic City.
Click image to enlarge. Credit: billmckibben/twitter

It was that record storm surge that caused most of the damage along the New Jersey coast and into New York City, where it inundated every subway tunnel between Manhattan, Queens, and Brooklyn, and helped cut power to lower Manhattan for days. The surge was also the dominant cause of storm deaths, with 41 victims, the report said.

In total, the storm was responsible for 147 direct deaths, the destruction of at least 650,000 homes, and it caused at least $50 billion in damage and left about 8.5 million customers without power.

The assessment team, which included meteorologists, emergency management officials, and social scientists from NOAA, FEMA, and the Centers for Disease Control and Prevention (CDC), focused especially closely on the National Weather Service’s (NWS) forecasts and warnings, including the policies underlying the warnings and watches that were issued; the efficacy of NWS websites as portals for storm information; and the production and issuance of storm surge-related forecasts.

The assessment praised the NWS for its advanced notice of the storm’s threat, and for emphasizing its potential to cause significant damage. The agency first highlighted the potential for the storm to bring major coastal impacts with nine days’ lead-time. The forecasts the agency issued, including the surge forecasts, were remarkably accurate, the report found, but it found fault with the ways the forecasts were communicated.

In particular, the assessment found that the storm-surge guidance provided by the agency’s various offices were often confusing and lacked any graphical presentation. The storm surge caused coastal flooding to exceed 8 feet above ground level in some areas, including in portions of New York City, and water rise was noted from Florida to Maine, the report said.

Ocean City, New Jersey.
Click image to enlarge. Credit: kenshane/twitter.

The report identified the urgent need for high-resolution storm-surge forecasting and communication as the “highest priority need” to emerge from the Sandy review process. “In particular, there is a crucial need for storm-surge graphical inundation guidance,” the report said.

In addition, the report said that the issuance of non-tropical watches and warnings did confuse some emergency managers, including the New York City Office of Emergency Management. That finding lends credence to the possibility that the lack of a hurricane warning, along with confusion over Sandy’s storm-surge potential, played a role in the actions of New York Mayor Michael Bloomberg, who initially downplayed the storm’s potential impacts in a press conference two days before the storm made landfall, only to reverse course and order the evacuation of low-lying areas the next day.

“(The) NYC Office of Emergency Management (OEM) was confused about the storm-surge forecast, what and where the impacts would be, and how high the water would rise,” the report said.

After a press conference on Oct. 27, at which Bloomberg had downplayed the storm’s threat, in part because it was not predicted to be a hurricane at the time of landfall, staff at the National Hurricane Center (NHC) called the OEM directly. According to the report, the city’s emergency managers considered the call to be “an eye-opener” about the potential storm-surge impacts in the city.

“This apparent communication breakdown may have delayed critical decision making about evacuations and led to potentially confusing messaging to the public,” the report said

"It is not expected to be a tropical storm or hurricane-type surge," Bloomberg said on Oct. 27. "With this storm we're likely to see a slow pileup of water rather than a sudden surge which is what you would expect from a hurricane and which we saw with Irene 14 months ago, so it will be less dangerous but make no mistake about it there will be a lot of water and low-lying areas will experience flooding."

In response to the NOAA report, the OEM said the storm surge forecast for New York changed between Oct. 27 and 28, which is why the evacuation was ordered on the 28th.

"NOAA's characterization of OEM and other Emergency Managers as 'confused' in its review of the surge data provided by NWS fails to address a key fact: The NWS surge forecast provided to OEM changed significantly between October 27 and 28 — from 4-8 feet to 6-11 feet. This was the key driver of the city's decision to order an evacuation on October 28," an OEM spokesperson told Climate Central.

The report found that even NWS personnel were confused by the ways in which NOAA measures storm surge, such as the height of water above the often-cited Mean Lower Low Water level.

Perhaps most importantly, the report found that the NWS and media were unable to translate the storm-surge forecasts from mere numbers to effective graphics and impact information.

“The public and NOAA/NWS partners did not clearly understand what storm surge was or how dangerous it could be,” the report said. “Most of the media representatives the Service Assessment Team interviewed believe NWS is not giving them any means to communicate predicted surge impacts to the public.”

One anonymous media representative quoted in the report said, “There were forecasts, but there were no details about what the predicted surges would cause . . . There was no wording in the warning like, 'Most of lower Manhattan will be underwater at a certain point' or, 'Staten Island will flood up to Beach Street.' ”

NWS Director Louis Uccellini said he intends to implement the report's 23 major recommendations for service improvements. “I was very impressed with the thoroughness of the job that they did,” Uccellini said in an interview regarding the assessment team's work. “We’re going to appraise the report, work with it, and implement it," he said.

A GOES-13 satellite image taken on Oct. 29, 2012 shows Hurricane Sandy centered off of Maryland and Virginia.
Credit: NOAA

The report also cited a March 2013 poll that found that 79 percent of coastal residents surveyed said the storm-surge impacts in their area was “more than they expected.”

In response to Hurricane Sandy as well as other recent storms, such as Hurricane Isaac in 2012, the National Hurricane Center (NHC) is currently developing storm-surge warnings and plans to roll out new inundation maps on a trial basis as soon as the upcoming 2013 hurricane season, which kicks off on June 1. The storm-surge warnings, however, will take at least another year to test and roll out.

The report found the NWS is impeded by a staffing shortfall in its storm-surge unit. Currently, the agency has just one full-time federal storm-surge forecaster at the NHC in Miami, along with two private sector storm-surge model developers.

The assessment found that the NWS made the decision not to issue hurricane warnings north of North Carolina due to the strong preference from the emergency management community, and at least one governor, that the warning type not change even if the storm were to transition from a tropical storm or hurricane into a post-tropical cyclone, as computer models predicted it would do.

Under policies in place at the time — which have since been changed — if a hurricane were to transition into a post-tropical cyclone prior to landfall, then local Weather Service forecast offices would be given responsibility for issuing non-tropical watches and warnings, rather than continuing to have hurricane warnings in place and coordinated from the National Hurricane Center in Miami.

In Sandy’s wake, NOAA has revised this policy, and has given the NHC the option to continue to keep hurricane watches and warnings in place even after a storm has transitioned into a post-tropical stage.

This new policy will enable NOAA to be consistent in the way it names tropical storms and hurricanes and issues warnings for them, and will prevent situations like Sandy in which forecasters are presented with an array of less-than-ideal options, each with the potential to confuse the public about how serious a storm really is.

Critics of the NWS’ decision not to issue hurricane warnings have contended that perhaps more people would have evacuated ahead of the storm, had those warnings been issued.

However, the assessment report rebuts that line of criticism by citing social science research showing that the lack of hurricane warnings did not cause people to react with reduced concern. Based on post-storm surveys, the report said that many people actually thought they were under hurricane watches or warnings when the storm struck, and that their level of concern “did not differ substantially” from respondents who thought a different type of warning was in effect.

“Many vulnerable residents ignore evacuation orders, even when they are accompanied by hurricane watches/warnings,” the report said.

While singling out the NWS New York and New Jersey offices for praise, the assessment faulted the NWS for the difficulty users had in finding critical information easily on the agency’s myriad different websites and social media platforms, noting that NOAA websites received close to 1.3 billion hits during the storm.

The team found that the heavily trafficked Hurricane Center homepage, for example, did not contain the flood and high wind warnings and storm bulletins from local forecast offices, as well as storm-surge information, issued by each office. The lack of a one-stop-shop for online information about the storm was problematic, and the New York OEM told the assessment team that they relied on a non-NOAA website for storm-surge guidance, which they found easier to use.

The report found that the NWS is ill-positioned to take social science insight about how people process and respond to storm-related information into account when wording its warnings and designing its graphics and websites, which can lead to ineffective products.

The NWS, the report said, has only one employee with doctoral-level training in a social science field, and the underrepresentation of social science expertise within the agency has hindered the effectiveness of the agency’s risk communications, especially during major events such as Sandy.

Good News, Bad News from New EIA Emissions Analysis

2013-05-15T13:56:23+00:00

There was good news and bad to be mined from a state-by-state analysis of carbon emissions over a decade, which was released this week by the U.S. Energy Information Administration (EIA).

Overall, the EIA reported that between 2000 and 2010, 38 states saw an overall drop in their annual energy-related carbon emissions, but between 2009 and 2010, as the economy began to rebound, most states’ overall fuel consumption increased and their carbon emissions rose.

How each state ranks depends on several factors. Texas, for example, has been the nation’s biggest carbon emitter for years, but it also has the country’s largest overall drop in carbon emissions since 2000. In contrast, Delaware had the biggest percentage decrease in emissions during the past decade (30 percent), but it is also the third-smallest emitter in the U.S. overall, so that decrease isn’t particularly important on the national level.

The amount of carbon dioxide each state emits from its energy use depends on many things, including the population, the climate (very cold and very warm states use a lot of energy for heating and air conditioning, respectively), and manufacturing and other economic activities. What fossil fuels are used in the state also matter. Burning coal produces more carbon emissions per unit of energy than oil, which in turn produces more than natural gas. And states with many people driving long distances end up with lots of carbon emissions from burning gasoline.

The EIA analysis looked at carbon emissions that came from gas-powered cars and coal and gas-fired electricity generation, but it also included emissions from any fossil fuel burned in homes, businesses and industry.

Here’s a look at what the new EIA data show about the top five biggest emitters.

Texas

the bad news: Texas has long been the biggest CO2 emitting state in the country, producing more than 650 million tons of CO2 each year. That’s nearly double the next biggest-emitting state, California.

the good news: Texas’ energy-related carbon dioxide emissions have shrunk by about 8 percent since 2000 and during that time, it’s been relying on less carbon-intensive forms of energy. On a per capita basis, Texans produce only slightly more emissions than the national average.

California

the bad news: As the nation’s most populous state, California emits the second-largest amount of carbon dioxide from its energy use. In 2010, California produced nearly 370 million tons of CO2 and more than half of that came from the transportation sector.

the good news: California’s per capita emissions are the third lowest in the country -- behind Rhode Island and Idaho -- and over the past decade, these per capita emissions have dropped by more than 10 percent.

Pennsylvania

the bad news: With nearly half of its electricity generated from burning coal, Pennsylvania is among the worst states in terms of how much carbon emissions come from its electricity sector.

the good news: Since 2000, Pennsylvania has seen the fourth-largest drop in overall energy-related carbon emissions, which have dropped by more than 7 percent.

Ohio

the bad news: Ohio has the nation’s second largest carbon-emitting electricity sector, with nearly 80 percent of its electricity coming from burning coal.

the good news: Over the past decade, Ohio has decreased its overall carbon emissions by more than 5 percent, slightly more than the national average.

Florida

the bad news: Florida’s energy-related carbon emissions topped 240 million tons in 2010, which is nearly 3 percent larger than it was 10 years ago (most states have decreased their energy-related emissions over that same time).

the good news: Florida has the ninth-lowest per capita emissions and, like most other states, Florida has seen an overall decarbonization of its energy supply over the past decade.

Amid Rapid Arctic Warming, U.S. Releases New Strategy

2013-05-14T17:12:38+00:00

With ministers from the eight Arctic states meeting Wednesday in Kiruna, Sweden, for the 2013 ministerial meeting of the Arctic Council, the Obama administration has laid out a broad new U.S. Arctic policy that sets strategic goals for how the U.S. will cope with the rapidly changing region. The “National Strategy for the Arctic Region” features the conflicting goals of accessing some of the Arctic’s potentially abundant natural resources — such as oil, gas, and minerals — and the need to protect the once pristine environment of a region that is only becoming more accessible because of global warming.

A fjord in Southeast Greenland, seen from a NASA aircraft in 2013.
Credit: NASA/Flickr.

The Arctic is one of the most rapidly warming areas on the planet, and the region’s once impenetrable sea ice cover is shrinking in area and thinning at a pace that has exceeded scientists’ most pessimistic predictions. Sea ice extent and volume reached record lows in 2012, continuing a long-term trend seen since the beginning of satellite monitoring in 1979. Studies show that most of the modern sea ice melt is most likely largely due to manmade global warming.

“The current Arctic warming trend is unlike anything previously recorded,” said a senior White House official during a press briefing on the new Arctic strategy on Friday.

The new strategy does not provide details on how policy makers intend to resolve what are starkly opposing interests.

On the one hand, the U.S., like other Arctic and even many non-Arctic states, is seeking to take advantage of new shipping routes and oil and gas reserves made accessible by the precipitous loss of sea ice. That is in line with the Obama administration’s “all of the above” energy approach. However, those activities would add more global warming pollution, which would do further harm to the Arctic environment, and they also pose the risk of oil spills and other accidents.

“We are looking to find ways to pursue these efforts in a way that looks to minimize damage to the environment,” the administration official said.

So far, attempts to drill for oil and gas in the harsh Arctic environment have proven problematic. Shell, for example, was forced to shut down their exploratory drilling operations north of Alaska after a series of widely publicized accidents that eventually drew the scrutiny of regulators.

The prospect of a seasonally ice-free Arctic — which scientists project could occur with steady regularity by the middle of the century, if not earlier — has sent countries scrambling for influence in the Far North. According to figures cited in the strategy document, the region is rich. It has approximately 13 percent of the world’s undiscovered oil and 30 percent of the world’s undiscovered gas deposits, along with vast and valuable mineral resources.

The new national strategy builds off of a brief policy directive issued by the Bush administration in 2009, and identifies three “lines of effort” on which the U.S. plans to focus. These include advancing U.S. security interests in the region, which would include adding Arctic infrastructure and capabilities, “including ice-capable platforms as needed.”

U.S. Secretary of State John Kerry is greeted by Swedish Ministry of Foreign Affairs' Chief of Protocol Caroline Vicini upon arriving in Kiruna, Sweden, for the Arctic Council’s Ministerial Meeting.
Credit: State Department.

The plan does not, however, detail how to go about implementing such infrastructure investments, such as adding to the currently limited U.S. icebreaker fleet. According to the administration, that fleet is down to one active ship, one ship that is soon to complete repairs, and another vessel that is being scavenged for parts. Other countries, including Canada as well as non-Arctic states such as China, are building icebreakers and ice-resistant ships that can operate in the region year-round.

The vagueness of the document was criticized by the Arctic Institute, a think tank based in Washington. “There is no mention of specific plans to upgrade the inadequate and outdated icebreaker fleet, to build physical infrastructure such as deep-water ports, or to invest in facilities and equipment for the Coast Guard’s operations in Alaska’s northern region,” wrote Mihaela David, a fellow at the institute, in an online analysis.

“Despite a good-faith effort at articulating policy priorities and formulating mutually reinforcing objectives, the U.S. Arctic strategy remains as elusive as a mirage on the Arctic ice sheet,” David wrote. “The strategy is toothless in the absence of a comprehensive implementation strategy and long-term budgetary plan.”

The Arctic strategy also calls for the U.S. to strengthen international cooperation in the Far North, through the Arctic Council, which is a non-binding cooperative body made up of the eight Arctic states and indigenous peoples, as well by working one-on-one with other countries and the private sector. The Council is the only diplomatic forum that is solely dedicated to the entire Arctic region.

“As an Arctic nation, the United States must be proactive and disciplined in addressing changing regional conditions and in developing adaptive strategies to protect its interests,” the national strategy document states.

At the meeting in Kiruna, which U.S. Secretary of State John Kerry will attend, Arctic nations will decide whether to admit 14 applicants for observer status in the Arctic Council, including China and the European Union. The large number of applicants reflects the growing interest in the Arctic among states that don’t have any territory in the region. Observers can contribute to Arctic Council activities, but only representatives of the eight Arctic states get a vote.

Ministers will approve the Council's work plan for the next two years, when Canada will head up the group, and are expected to sign an agreement on preparing for and responding to Arctic marine oil pollution. That would be only the second legally binding agreement forged among the Arctic states, after a search-and-rescue agreement that was signed in 2011.

Kerry will be only the second Secretary of State to attend one of the Council's ministerial-level meetings. His predecessor, Hillary Clinton, became the first to do so in 2011, reflecting the growing importance of Arctic issues in U.S. diplomacy. Previously, meetings were attended by lower-level officials from the State Department.

Tinderbox-Dry Western U.S. at High Risk of Major Wildfires

2013-05-13T19:39:51+00:00

Federal officials are preparing for another challenging fire season, driven by tinderbox dry conditions in much of the West, and complicated by budget cuts that will limit the number of firefighters agencies can put in the field.

“We are facing another dangerous wildfire season,” said Interior Secretary Sally Jewell, speaking to reporters from the National Interagency Fire Center (NIFC) in Boise, Idaho. Jewell noted that 12 of the hottest years in the West have occurred during the past 15 years. As temperatures have increased, due in part to manmade global warming, and spring snowpack has melted earlier, large wildfires have become more common across parts of the West.

A wildfire burns in the Gila National Forest in New Mexico in 2012. New Mexico is at risk of potentially large wildfires again in 2013 due to sharply reduced precipitation.
Credit: National Forest Service.

The anticipated escalation in U.S. wildfire activity comes after the slowest start to wildfires in at least 10 years, according to Jeremy Sullens, a forecaster at NIFC.

Due to a combination of drought and record heat, 2012 saw one of the most destructive wildfire seasons on record, with 9.3 million acres going up in flames, the third-highest since 1960, said Agriculture secretary Tom Vilsack on the conference call.

The below-average wildfire activity to date has mainly been due to recent rains in the Southeast, which has limited fire risk. So much rain fell in Georgia during March and April that a two-year, severe drought all but vanished, effectively canceling that state’s spring wildfire season. The below-average number of wildfires so far this year, Jewell said, “has no bearing on where we think this fire season is going to go.”

During the rest of May and June, the wildfire focus will shift West, where, according to Sullens, “It’s a very different story.” Drought conditions have encompassed nearly the entire Western half of the country, with the worst of it centered in the Southwest and into California, which received only about 25 percent of its average precipitation during the year-to-date. “We’re confident we’re going to see above-normal significant fire potential,” Sullens said.

California has gotten a head start on its wildfire season, with several large blazes occurring earlier in May, including the Springs Fire near Los Angeles.

Sullens said that there is above-average wildfire potential from the Southwest and into the Four Corners region during the first half of summer, until the Monsoon Season kicks in later in July. In New Mexico, the 30-month period ending in March 2013 was the driest on record, and reservoir and river levels are reflecting this shortfall. The Brantley Reservoir on the Pecos River in southeastern New Mexico is at just 1 percent of capacity; and the combined storage in the four reservoirs on the Pecos River is at 25 percent, according to the latest U.S. Drought Monitor.

Forecasters are also concerned about a high risk of large wildfires along the Pacific Coast from California northward to Washington, and inland into Idaho and Southwest Montana, where very dry conditions exist in areas that have an abundance of vegetation, or fuel, to support potential fires.

A satellite image showing the burn scar (area in red) from the Springs Fire in California.
Credit: NASA.

Large blazes are becoming more common in the West as average temperatures increase and spring snowmelt occurs earlier in the year. In addition, land-use changes have helped contribute to more wildfires as communities expand into previously unoccupied territory.

Compared to an average year in the 1970s, during the past decade there were seven times more fires greater than 10,000 acres each year, and nearly five times more fires larger than 25,000 acres each year, according to Climate Central research.

Vilsack said the combination of the drought, an abundance of dead or weakened trees from an epidemic of mountain bark beetles, and a likelihood of another unusually hot and dry summer is “a combination that doesn’t bode well."

Budget Cuts Force Agencies to Focus on Short-Term Priorities

Federal agencies, led by the USDA and Interior Department, will have to fight this season’s fires with fewer people and equipment than they are used to, due to mandatory budget cuts known as the “sequester,” as well as other budget cuts to a variety of programs. The sequester, which took effect on March 1, required across-the-board spending cuts to virtually all federal agencies and programs.

That means that the federal government will have a smaller arsenal of firefighters and equipment to devote to combating this summer’s blazes. Instead of the 10,500 firefighters the Agriculture Department typically fields, Vilsack said this year there will be only 10,000, along with 50 fewer fire trucks than normal. In total, the federal government will have more than 13,000 fire personnel at its disposal, including permanent and seasonal federal employees; up to 26 multi-engine air tankers and two water scooper aircraft; along with about 27 single-engine air tankers, and hundreds of helicopters.

Jewell, who is just beginning her fifth week on the job, said the Interior Department is putting an emphasis on protecting lives and property from wildfires, which means that fewer resources are being devoted to other agency programs.

Ironically, both the Agriculture and Interior Departments have been forced to cut programs that are aimed in part at reducing wildfire risk over the long-term, in order to ensure that enough firefighting resources are available this year.

For example, Vilsack said the U.S. Forest Service’s forest-thinning projects are being scaled back, which could increase wildfire risk in the future. “We’re going to do the best we can to maximize the utilization of the resources that we have to safeguard life and property,” Vilsack said.

Warming Could Slash Species’ Habitat Ranges in Half

2013-05-13T15:20:55+00:00

Vast numbers of plant and animal species could see their ranges slashed in half later this century as a result of climate change, according to a study in Nature Climate Change. The result, say the authors, could be serious ecosystem disruptions along with the loss of so-called “ecosystem services,” such as the purification of air and water; erosion and flood control; and the recycling of nutrients that natural systems provide.

Earlier studies have focused on the complete extinction of species; this one, by contrast, deliberately steered clear of those at unusually high risk. “We wanted to focus on common, widespread species,” said lead author Rachel Warren, of the University of East Anglia, in the United Kingdom, in an interview.

Sunrise at Chincoteague National Wildlife Refuge, Virginia.
Credit: U. S. Fish and Wildlife Service - Northeast Region/flickr.

In the end, Warren and her colleagues looked at about 50,000 species drawn from an international database, and compared how fast climate zones are likely to shift with how fast individual species can move in order to keep up with that shift.

What they found was that about 57 percent of plants and 37 percent of animals are likely to see their habitats slashed by 50 percent or more by 2080, if greenhouse gas emissions grow unabated.

"The terrifying loss of biodiversity predicted by this study shows that climate chaos will fundamentally transform our planet," said Shaye Wolf, climate science director for the Center for Biological Diversity, in San Francisco, in a statement.

While some may think that ranges would simply shift — and not shrink — as the planet warms, that’s not the case. If a given species lives at high altitude, for example, its range will shift even higher — but when it gets to the top of a mountain, there’s no place higher to go.

Warming temperatures also drive habitat ranges away from the tropics and toward the poles, but, said Warren, “in some places, like southern Africa or southern South America, you can’t go any further south.” And even if a species lives on a flat plain far from any coast, she said, and the new climate zone has the same area as the old, “a species has to be able to get there.”

If a species can’t keep up with the moving climate zone, its range will be constricted in any case. “Mammals and birds have an easier time. Amphibians, reptiles, and especially, plants, have more trouble,” Warren said. A plant that reproduces by dropping seeds a few meters from the parent, she said, “can only move a short distance with every generation.”

This shows yet another problem with shifting ranges: if different plants and animals within an ecosystem move at different rates, the ecosystem itself might be disrupted — if, say, animals moved faster than the plants they’ve evolved to prefer, they could suffer. “That’s something we didn’t include in this study, which is one reason our projections are actually somewhat conservative,” Warren said.

The only good news is that these disruptions aren’t inevitable: they could be partially forestalled by cutbacks in greenhouse-gas emissions. “With mitigation . . . losses are reduced by 60 percent if emissions peak in 2016 or 40 percent if emissions peak in 2030,” Warren and her colleagues wrote.

Whether that’s likely to happen is another story. “Obviously, I’m aware that the political machine is working very slowly,” Warren said. Still, several countries have at least made pledges to reduce their emissions. “There’s still a large gap between what these commitments would deliver and what we call for. But at least those are steps in the right direction,” Warren said.

Amazon May Lose 65 Percent of Land Biomass by 2060

2013-05-13T13:16:21+00:00

By Alex Kirby, Climate News Network

LONDON — There will be no winners if agriculture made possible by widespread felling in the Amazon continues to expand, say researchers from Brazil and the U.S.

They calculate that the large-scale expansion of agriculture at the expense of the forest could entail the loss of almost two-thirds of the Amazon’s terrestrial biomass by later this century.

Making more land in the Amazon available for farming and ranching means felling more trees to make space – and researchers say that risks meaning that more agricultural expansion will simply mean less production, because of deforestation’s effect on the climate.
Credit: Dams999/flickr.

Their study, published in the journal Environmental Research Letters, shows that deforestation will not only reduce the capacity of the Amazon’s natural carbon sink.

It will also cause climate feedbacks that will decrease the productivity of pasture and soybeans — the reason advanced for felling the trees in the first place.

Brazil is under intense pressure to convert the Amazon forests to produce crops and provide pasture for cattle. But the forests’ natural ecosystems sustain wild food production, maintain water and other resources, regulate climate and air quality and ameliorate the impact of infectious diseases.

The researchers are from the Brazilian federal universities of Viçosa, Pampa, Minas Gerais and the Woods Hole Research Center in the U.S.

They used model simulations to assess how the agricultural yield of the Amazon would be affected under two different land-use scenarios: one, business-as-usual, where recent deforestation trends continue and new protected areas are not created; and the other a governance scenario, which assumes Brazilian environmental legislation is implemented.

They predict that by 2050 a decrease in precipitation caused by deforestation will reduce pasture productivity by 30 percent in the governance scenario and by 34 percent in the business-as-usual scenario.

They say increasing temperatures could cause a reduction in soybean yield by 24 percent in the governance scenario and by 28 percent under the business-as-usual scenario.

It is significant that the study finds relatively little difference between the outcomes of the two scenarios, perhaps suggesting that Brazil needs to tighten its environmental legislation drastically and to enforce it more effectively.

Slash and burn agriculture in The Amazon.
Credit: Threat to Democracy/flickr.

“…it was a surprise to us that high levels of deforestation could be a no-win scenario — the loss of environmental services from the deforestation may not be offset by an increase in agricultural production”

Perhaps the authors’ starkest conclusion is that a combination of the forest biomass removal itself, and the resulting climate change, which feeds back on ecosystem productivity, could result in biomass on the ground declining by up to 65% for the period 2041-2060.

And all this would achieve little or nothing in terms of food production. The researchers write: “…total agricultural output may either increase much less than expected proportional to the potential expansion in agricultural area, or even decrease, as a consequence of climate feedbacks from changes in land use.

“These climate feedbacks, usually ignored in previous studies, impose a reduction in precipitation that would lead agricultural expansion in Amazonia to become self-defeating: the more agriculture expands, the less productive it becomes.”

The lead author of the study, Dr. Leydimere Oliveira, said: “We were initially interested in quantifying the environmental services provided by the Amazon and their replacement by agricultural output.

“We expected to see some kind of compensation or off-put, but it was a surprise to us that high levels of deforestation could be a no-win scenario — the loss of environmental services from the deforestation may not be offset by an increase in agricultural production.”

The study shows that the effects of deforestation will be felt most in the eastern Pará and northern Maranhão regions. Here the local precipitation appears to depend strongly on the forests, and changes in land cover would drastically affect the local climate, possibly to the point where agriculture became unviable.

“There may be a limit to the expansion of agriculture in Amazonia. Below this limit, there are not important economic consequences”, said Dr Oliveira.

“Beyond this limit, the feedbacks that we demonstrated start to introduce significant losses in agricultural production.”

Alex Kirby is editor of Climate News Network. Climate News Network is a journalism news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.

China ‘Moving to Lead on Climate Change,’ Says Report

2013-05-12T14:01:22+00:00

By Alex Kirby, Climate News Network

Both China and the U.S., the world’s two principal emitters of greenhouse gases, have been making significant recent progress on tackling climate change, a report by an influential Australian advisory group says.

Its report, The Critical Decade: Global Action Building on Climate Change, has particular praise for China, saying its efforts “demonstrate accelerating global leadership.”

The other “energy giant,” the U.S., is also commended for showing “a new commitment to lead.” The report says the U.S. “appears to be gaining momentum with President Barack Obama outlining his strong intent to address climate change…”

That was then ... despite being one of the biggest emitters of greenhouse gases, China is earning high praise for its efforts to tackle climate change.
Credit: High Contrast

The report is the work of the Australian Climate Commission, an independent body set up in 2011 to provide authoritative and trustworthy information on climate change science and solutions.

Its authors are Professor Tim Flannery, chair of the Commission, Gerry Hueston, former CEO of BP Australasia, and Roger Beale, an economist and former Secretary of the Australian Department of Environment.

The report says China and the U.S., the world’s two largest economies which together produce about 37 percent of world emissions, are both on track to meet their international commitments on climate change, something they said in this month’s “historic agreement” they would tackle together. “Today the energy giants are undoubtedly on the move, which will fuel global momentum.”

Halving electricity demand

China earns praise for several reasons. It is reducing its emissions growth, and in 2012 cut the carbon intensity of its economy more than expected. After years of strong growth in coal use, the rate of growth has declined substantially. It is also “the world’s renewable energy powerhouse.”

Professor Flannery says: “China has halved its growth in electricity demand… [and] is quickly moving to the top of the leader board on climate change.”

Emissions have also been declining in the U.S., which is on track to meet its goal of cutting them by 17 percent on 2005 levels by 2020. The authors note that the economic downturn and a shift away from coal to gas have helped here.

Global progress on renewable energy graphic.
Credit: Climate Commission

The report says every major economy is tackling climate change, introducing policies to drive down emissions and encouraging renewable energy.

But in a section headed “This is the critical decade for action,” it says the significant progress made so far is not enough. “Globally emissions are continuing to rise strongly, posing serious risks for our society. This decade must set the foundations to reduce emissions rapidly to nearly zero by 2050.”

The scale and the pace of the changes needed to reduce emissions as drastically as that – something which many scientists insist is vital – is a huge challenge, and many countries appear on present trends very unlikely to meet it.

A report in the Sydney Morning Herald on April 26, headlined “Japan turns back to coal-fired power plants,” included this observation on the country’s post-Fukushima prospects: “…with the government considering the closure of much of the installed nuclear capacity over the medium term, the spotlight is back on coal as the cheapest energy source, notwithstanding plans to cut carbon emissions.

“A commitment to slice 2020 carbon emissions by 25 percent from their 1990 level will be revised by October, according to Japanese newspaper reports.”

Action needed now

The Australian report’s praise for China and the U.S. commends their recent performance – or at least their stated intentions – in comparison with their past records. But they will need to do far more than show the relative improvement the Commission recognizes.

If the Earth is still to have any chance of staying below the 2°C global average temperature rise, which most governments say is essential to prevent dangerous climate change, the energy giants (and the rest of the world) will have to make vastly greater absolute progress.

Alex Kirby, a former BBC environment correspondent, is a founding journalist of Climate News Network. Climate News Network is a news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.

Warming Temps Cause Trees to Limit Warming—a Little

2013-05-12T12:30:14+00:00

By Tim Radford, Climate News Network

Trees may provide the Earth with a little shade from global warming – indirectly. European and Canadian researchers report that they have found what engineers like to call a negative feedback loop above the forests of Europe and North America.

It works like this. Trees – those natural chemical factories that routinely deliver complex aromatic compounds such as rubber, coffee, chocolate, resins, pungent fruits, oils and natural drugs such as quinines – are a permanent source of volatile organic compounds released into the atmosphere.

The Smoky Mountains of Tennessee and North Carolina take their name from the pall of isoprenes discharged from the oaks that cover the hills: the mountains actually look smoky.
Credit: John Phelan

On a hot day, trees release even more conspicuous quantities of terpenes, isoprenes and other compounds into the air. These are wafted higher in the atmosphere and begin to mix, oxidize, or chemically react with other atmospheric gases, aerosols and car and factory exhausts to form increasingly larger particles on which water vapor might condense.

This is not a new observation. The Smoky Mountains of Tennessee and North Carolina take their name from the pall of isoprenes discharged from the oaks that cover the hills: the mountains actually look smoky.

The aerosols from trees float in the atmosphere and reflect and scatter sunlight and even form cloud droplets. So far, so familiar.

But Pauli Paasonen, of the University of Helsinki and the International Institute for Applied Systems Analysis in Laxenburg, Austria, writes in Nature Climate Change that he and 23 colleagues in Finland, Sweden, Germany, Canada and the U.S. decided to assess the overall effect of these aerosols and their contribution to, or impact upon, global warming.

Every little helps

They analyzed data from eleven measuring stations spread across the northern hemisphere, from semi-Arctic wilderness to polluted agricultural lands, and worked out how the quantities of cloud condensation nuclei might be linked to air temperatures.

They found a clear connection. The warmer the weather, the greater the likelihood that gas emissions from plants would create conditions for the formation of clouds, which in turn would reflect more sunlight back into space, and thus help damp down global warming.

The warmer the weather, the more likely gas emissions from plants would create conditions for the formation of clouds, which would reflect more sunlight back into space, thus help damp down global warming.
Credit: flickr/Grant MacDonald

That is the good news. The not-so-good news is that these plant gas emissions won’t make a great deal of difference – on a global scale they might counter about 1 percent of global warming.

On a regional scale, however, the effect might be much greater: in heavily forested areas – Finland, Siberia and Canada, for instance – where human emissions of aerosols are anyway relatively slight, plant gas releases might counter as much as 30 percent of warming.

The effect however was not easy to predict, and may not be easy to confirm. The key variable is the boundary layer of the atmosphere at which gases and particles mix and form the nuclei around which cloud droplets might condense, and the height of this boundary changes with weather conditions.

“Plants, by reacting to changes in temperature, also moderate these changes”, says Dr Paasonen. “One of the reasons that this phenomenon was not discovered earlier was because these estimates for boundary layer height are very difficult to do.”

Six to See: Slideshow of This Week’s Top Climate News

2013-05-11T14:19:05+00:00

Slideshow

Warmer Climate Threatens Africa’s Vital Cassava Crop

2013-05-11T12:30:31+00:00

By Alex Kirby, Climate News Network

A plant which is a staple food crop for millions of people across Africa is at risk from disease as regional temperatures rise, scientists say.

The plant, cassava, is a significant source of food and income, and is an important industrial crop, and there is concern that serious food shortages may result and poverty worsen.

Experts say the spread of the disease could halve cassava production and threaten the diets of 300 million people.

Experts say the spread of the disease could halve cassava production and threaten the diets of 300 million people.
Credit: Tom Rulkens

The disease responsible, Cassava Brown Streak Disease (CBSD) is transmitted by insects whose numbers are surging, with rising temperatures thought to be one of the factors causing the increase.

CBSD was first identified in East Africa in the 1930s. It is deceptive, because an infected plant’s leaves may continue to look healthy while the roots beneath are being destroyed.

It is only when the roots are dug up and found to be streaked with brown that farmers know their crop is infected. The roots are rich in carbohydrates and are used both for food and to make starch, flour, biofuel and beer.

New outbreaks of CBSD have been reported recently in the Democratic Republic of Congo — the world’s third largest cassava producer — and Angola.

Rambo crop

If it spreads to West Africa that will be especially serious. Nigeria alone now produces 50 million tons of cassava annually and plans to use the crop widely in its agricultural and industrial development.

“Cassava is already incredibly important for Africa and is poised to play an even bigger role in the future, which is why we need to move quickly to contain and eliminate this plague,” says Claude Fauquet, a scientist at the International Center for Tropical Agriculture who heads the Global Cassava Partnership for the 21st Century (GCP21).

“We are particularly concerned that the disease could spread to West Africa and particularly Nigeria — the world’s largest producer and consumer of cassava — because Nigeria would provide a gateway for an invasion of West Africa where about 150 million people depend on the crop.”

To counter another viral scourge, Cassava Mosaic Disease (CMD), scientists developed varieties of the plant which are resistant to it. Unfortunately, though, the CMD-resistant varieties are not proof against Brown Streak Disease.

Cassava has a reputation as a tough and resilient performer in conditions where many other crops cannot flourish, and so has been seen as a good way for farmers in sub-Saharan Africa to guard against the effects of climate change.

Research published in the journal Tropical Plant Biology found it could cope with the temperature rises of up to 2°C expected in West Africa by 2030, and would generally outperform six other crops — potato, maize, bean, banana, millet, and sorghum.

The report’s lead author, Andy Jarvis, said: “Cassava is a survivor; it’s like the Rambo of the food crops. It deals with almost anything the climate throws at it.”

Out-competed

“It thrives in high temperatures, and if drought hits it simply shuts down until the rains come again. There’s no other staple out there with this level of toughness.”

“The ideal situation is for farmers to have a diversity of crops, with cassava acting as a failsafe. This would enhance nutrition and reduce climate risk.”

But, in another twist of fate, it is rising temperatures which now threaten cassava because they appear to be one of several factors which are causing an explosion in whiteflies, the insects which carry the viruses that cause CMD and CBSD.

This, coupled with what scientists think are genetic changes leading to the emergence of “super” whiteflies, now means that large swathes of Africa face the prospect of intensified food insecurity.

“We used to see only three or four whiteflies per plant; now we’re seeing thousands,” said James Legg, a leading cassava expert at the International Institute of Tropical Agriculture. “You have a situation where human beings are competing for food – with whiteflies.”

Claude Fauquet says: “It’s time for the world to recalibrate its scientific priorities. More than any other crop, cassava has the greatest potential to reduce hunger and poverty in Africa, but CBSD and other viruses are crippling yields.

“We need to treat CBSD and other destructive viruses like the smallpox of cassava – formidable diseases, but threats we can eradicate if everyone pulls together.”

Alex Kirby, a former BBC environment correspondent, is a founding journalist of Climate News Network. Climate News Network is a news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.

Carbon Dioxide Passes 400 PPM Milestone, NOAA Finds

2013-05-10T16:50:59+00:00

On May 9, the amount of carbon dioxide in the air exceeded 400 parts per million (ppm) for the first time in the observational record since 1958, and very likely for the first time in at least 800,000 years, the National Oceanic and Atmospheric Administration (NOAA) announced on Friday. This marks the first time the daily average CO2 concentration has risen past 400 ppm in the iconic record kept by the Mauna Loa Observatory in Hawaii, where daily observations go back to 1958,

Climate scientists recognize this 400 ppm mark as a symbolic milestone, illustrating the rapid increase of human-caused CO2 emissions over the past century. Numerous other climate data, gleaned from ice cores, ocean sediment, and other sources show that this is the highest CO2 concentration in the air in all of modern human history, possibly as far back as 15 million years ago.

Record of atmospheric carbon dioxide concentrations dating back 800,000 years (left) and during the course of the Mauna Loa record (right inset).
Click on the image to enlarge.

Carbon dioxide is the most important long-lived global warming gas. Once CO2 is emitted by burning fossil fuels such as coal and oil, a single CO2 molecule can remain in the atmosphere for hundreds of years. Global CO2 emissions reached a record high of 35.6 billion tons in 2012, up 2.6 percent from 2011. Carbon dioxide and other greenhouse gases warm the planet by absorbing the sun’s energy and preventing heat from escaping back into space.

Mauna Loa, as the oldest continuous carbon dioxide (CO2) measurement station in the world, is the primary global benchmark site for monitoring the increase of this potent heat-trapping gas. Carbon dioxide concentrations have steadily increased since scientists started making measurements on the slopes of the Hawaiian volcano more than five decades ago.

Reflecting the increase in manmade emissions of the gas, the rate of increase in CO2 levels has accelerated since the measurements began, from about 0.7 ppm per year in the late 1950s to 2.1 ppm per year during the last 10 years, NOAA said in a press release. Today’s rate of increase is more than 100 times faster than the increase that occurred when the last ice age ended, and this is driving a rapid increase in global average surface temperatures.

Before the start of the Industrial Revolution, global average CO2 was about 280 ppm, and it fluctuated between about 180 ppm and 280 ppm during the past 800,000 years, NOAA reported.

“The evidence is conclusive that the strong growth of global CO2 emissions from the burning of coal, oil, and natural gas is driving the acceleration,” said Pieter Tans, with the Global Monitoring Division of NOAA’s Earth System Research Laboratory in Boulder, Colo., in a press release.

As Climate Central reported on May 3, there is no single, agreed-upon answer to when CO2 concentrations were last at this level, as studies show a wide date range from between 800,000 to 15 million years ago. The most direct evidence comes from tiny bubbles of ancient air that act as time capsules, sealing ancient air in the vast ice sheets of Antarctica and Greenland. By drilling for ice cores and analyzing the air bubbles, scientists have found that, at no point during at least the past 800,000 years have atmospheric CO2 levels been as high as they are now.

A 2011 study in the journal Paleoceanography found that atmospheric CO2 levels may have been comparable to today’s as recently as sometime between 2 and 4.6 million years ago, during the Pliocene epoch, which saw the arrival of Homo habilis, a possible ancestor of modern homo sapiens, and when herds of giant, elephant-like Mastadons roamed North America. Modern human civilization didn’t arrive on the scene until the Holocene Epoch, which began 12,000 years ago.

For a 2009 study, published in the journal Science, scientists analyzed shells in deep sea sediments to estimate past CO2 levels, and found that CO2 levels have not been as high as they are now for at least the past 10 to 15 million years, during the Miocene epoch. At this time, megatoothed sharks prowled the seas, which were up to 100 feet higher than they are now.

Although the daily average CO2 benchmark has been established, it is unlikely that the monthly average or annual average CO2 level will surpass 400 ppm this year. Typically, CO2 levels in the Northern Hemisphere peak each year in May, after which they drop slightly as trees and plants around much of the world suck up more CO2 as they grow more each summer. But with global carbon emissions showing no signs of slowing, it may only take another one to three years before the annual average surpasses 400 ppm as well. By the middle of the century, CO2 levels are expected to climb to 450 ppm or higher, depending on emissions.

Editor's Note: After this story was published, NOAA revised their numbers for May 9 to 399.89 ppm, and the Scripps Institution of Oceanography reported 399.73 ppm. The revision is due to additional analysis and differences in the methods used by these two institutions. As of May 14, NOAA data showed a reading of 400.07 ppm on May 13, indicating the 400 ppm threshold was still exceeded.

In Parched Southwest, Anxious Wait for Summer Rains

2013-05-10T11:59:28+00:00

On the thirsty rangelands of Arizona and New Mexico, which have been mired in an on-again, off-again drought since 1999, ranchers and water managers are hoping for an unusually wet summer monsoon season that will help make up for this winter’s lackluster snowpack. Reservoirs have been depleted to near-record lows, and the major rivers and tributaries are running at barely a trickle, making the summer rainfall season crucial to avert potentially severe water shortages, at least temporarily.

This cross-section of Douglas-fir from Arizona shows the tree's annual growth rings. Tree rings like this can be used as a proxy record for the climate.
Credit: Daniel Griffin/University of Arizona.

However, if the past two summer monsoon seasons are any guide to what’s ahead, meaningful drought relief may be wishful thinking.

“Another dry monsoon could be devastating,” said Victor Murphy, a climate services program manager with the National Weather Service.

Due in part to far below average river runoff from a thin mountain snowpack, which had all but vanished from the Southwest by mid-April, water rights and water allocation disputes have already begun to flare up along the Rio Grande and Pecos rivers.

In New Mexico, the 30-month period ending in March 2013 was the driest on record, and reservoir and river levels are reflecting this shortfall. The Brantley Reservoir on the Pecos River in southeastern New Mexico is at just 1 percent of capacity; and the combined storage in the four reservoirs on the Pecos River is at 25 percent, according to the latest U.S. Drought Monitor, released on May 9.

The Elephant Butte Reservoir in New Mexico’s “Chile Belt” is at 10 percent of capacity, with the lowest amount of water available for irrigation in the region in almost 100 years.

Water managers across the state are sharply reducing supplies for irrigating farms and other uses. About 40 percent of the state is currently mired in “exceptional drought” conditions, the most severe category listed on the U.S. Drought Monitor. The drought is likely to intensify and expand throughout May and June, which are typically dry and hot months in this region, before any appreciable mid-to-late summer rains arrive.

In recent years, the month of June has been trending progressively hotter, which is consistent with climate change projections, according to Jonathan Overpeck, co-director of the Institute of the Environment at the University of Arizona.

Scientists say there is no reliable way of predicting the summer monsoon, which typically brings showers and thunderstorms into Arizona and New Mexico beginning in mid-July and lasting until September. In a typical year, the months of July, August, and September are the three wettest consecutive months in New Mexico. However, the past two monsoon seasons have been below average, with the 2011 monsoon season coming in as the 14th-driest on record in New Mexico, and the 2012 season as the ninth-driest.

This year, with a thin spring snowpack already leading to scant summer runoff from the mountains, the stakes for the summer monsoon couldn’t be higher.

Southwest Monsoon Defies Predictability

Unlike other short-term climate cycles and the annual monsoon in South Asia, the Southwest Monsoon has defied most attempts to predict it accurately. “It is still not possible to predict with any confidence what the monsoon will do in any given year. The fact that it was a lousy snow year for the southern Rockies may allow earlier and greater heating of the land and atmosphere, which in turn, could drive a stronger monsoon, but this isn’t at all a sure bet,” Overpeck said in an email conversation.

The last two Southwest Monsoon seasons have featured below average rainfall in New Mexico, although not as low as other years, as this time-series shows.
Click on the image to enlarge. Credit: NOAA/NCDC.

The lack of El Niño or La Niña conditions in the tropical Pacific Ocean makes it even harder to predict the monsoon with much confidence, said Michael Crimmins, an associate professor at the University of Arizona. El Niño and La Niña events, which feature above and below average sea surface temperatures in the tropical Pacific Ocean, respectively, can influence the weather pattern that drives the monsoon, and enable forecasters to provide water managers with more useful information ahead of time, although even then the forecasts tend to be hit-or-miss.

Without either such event present, Crimmins said, “We don’t really have any signal to work with at all.”

“We’re all just kind of sitting tight and waiting,” he said.

Even an above average monsoon season won’t provide enough water to erase the long-term drought and restore the area’s rivers and reservoirs to near-normal levels. For that, the Southwest needs to see both higher than average spring snowpack and cooler-than-average conditions, a 1-2-punch that hasn’t happened consistently for several years.

However, a wet summer could still benefit ranchers, who have been forced to sell off many of their cattle due to the lack of food. Summer rains can quickly get grass growing in forage lands, which would be beneficial for ranchers. According to Crimmins, the drought has taken such a toll on many cattle herds during the past few years that ranchers might not be able to capitalize on a wet spell to the same degree that they have in the past.

Warmer, Drier Long-Term Outlook

The past few decades were the wettest period in the Southwest in about 1,000 years, said Crimmins, and this has effectively masked the region’s drought history for most of the region’s residents, many of whom moved there in just the past few decades from much wetter places in the Midwest and Northeast.

Arizona was the second-fastest growing state between 2000-2010, according to the U.S. Census Bureau, gaining 1.3 million new residents during this period. New Mexico gained about 240,000 residents during the same period.

Historical records show abundant evidence of multi-decadal droughts triggered by natural climate variability — droughts that were much more severe and long-lasting than what the region is experiencing today. A recent study using evidence found in tree rings concluded that the failure of both winter snow and summer monsoon seasons is a key characteristic of the region’s major, long-duration droughts.

“We know that drought can last decades down here,” Crimmins said.

Computer model projection showing the expected change in precipitation across North America, with a long-term drying trend in the Southwest U.S. and Mexico.
Credit: Lamont-Doherty Observatory.

Overpeck, of the University of Arizona, said the increase in average temperatures in the Southwest means that droughts are already having greater impacts than they used to. “This warming is a symptom of human-caused climate change, and droughts of the future will only get hotter and hotter on average,” he said.

Given the history of the region, along with climate research that shows that one very likely consequence of global warming will be hotter droughts and an overall, long-term drying trend in the Southwest, there is ample reason for scientists and water managers to be concerned that the population growth in places like Phoenix will put a tremendous strain on water resources.

“I don’t expect temperatures to return to 20th Century average conditions, and the effect of long-term warming on the water budget, added to all the other non-climate stresses on water resources here, is what makes 21st Century water management such a daunting challenge,” said David Gutzler, a professor at the University of New Mexico in Albuquerque.

Jet Stream Enhances Drought in West, Midwest Relief

2013-05-09T16:23:58+00:00

A week of wild and unusual weather brought a combination of record cold, snow flurries, heavy rains and 90-degree heat to different parts of the U.S. As a result of this weather pattern, which was characterized by a topsy turvy jet stream that caused storm systems to slowly inch across the country, drought shrank in some places and grew in others, but the changes followed the same pattern that has held for the past several weeks.

Heavy precipitation left most of the Midwest and Southeast nearly drought-free, while high temperatures and scant precipitation intensified drought and raised concerns across the West and Southwest.

According to the latest U.S. Drought Monitor, released Thursday, Florida saw the most drought improvement during the past week, while New Mexico saw the biggest deterioration. Modest to heavy rains fell all across the Southeast last week, and continued to eliminate patches of abnormal dryness that have lingered from the drought that afflicted the region for more than two years. In Georgia, drought came to a sudden end, as heavy rains erased a two-year drought in just two months.

U.S. Drought Monitor.
Credit: NOAA/USDA

Florida is now the only state in the Southeast with areas of moderate and severe drought, and both of those areas shrank significantly during the past week, where storms set rainfall records all across the state. South Florida set a record for the wettest 7-day period during this time of year, and Jacksonville saw more than 10 inches of rain during the past week.

The drought situation in the Southwest and West is a very different story. The region saw a few scattered showers during the past week, but they did little to combat the above average temperatures and months — and in some cases years — of below average precipitation that are creating a crisis in many Western states. This week, drought expanded slightly across California, Oregon, Nevada and Montana, but the worst impacts were being felt in the Southwest. In California, the drought contributed to early-season wildfires near Los Angeles, possibly heralding a severe wildfire season ahead.

In New Mexico, the past 30 months have been the driest on record. Much of the state has seen half of its average precipitation during the past six months, which has already impacted the state’s rivers and reservoirs, and is placing a severe strain on the many farmers and ranchers who rely on those sources of water throughout the year.

The total percentage of the lower 48 states under moderate drought or worse now stands at 48.06 percent, compared to 46.9 percent last week. The area of exceptional drought, the worst category, expanded to 4.38 percent this week, from 3.40 percent one week ago.

Prolonged drought in some areas is creating anxiety about the 2013 growing season. "We are starting out 2013 in by far the worst shape on record, with respect to U.S. pasture and rangeland conditions," said Brad Rippey, a Department of Agriculture meteorologist, in a press release. "This is on the strength of continuing drought from California to the Great Plains. This part of the country accounts for a disproportionately large percentage of the nation’s rangeland."

The heat and dryness across the Southwest this week contrasted sharply with the late-season snow, cold snap, and flooding that hit the Midwest. A storm system that hovered over the center of the country for several days brought cold temperatures and a blanket of snow to parts of Missouri, Iowa, Minnesota, Wisconsin, and as far south as Arkansas, shattering snowfall records in these states.

“The combination of wet and cool weather this year has definitely dented or eliminated the drought in much of the Midwest, and if these conditions continue, additional improvement is likely,” said David Miskus, lead author of this week’s Drought Monitor, in a statement accompanying the update.

Smoke blows out to sea from the Springs Fire in California, on May 2.
Click on the image to enlarge. Credit: NASA.

The biggest swings in weather this week affected the High Plains. “This week’s precipitation was a miss, hit, and miss in the northern, central and southern Plains, respectively,” said Miskus. Some single-category improvements were made in the eastern fringes of Kansas, and enough rain fell over northern Colorado and southeastern Wyoming to create six-month precipitation surpluses. However, much of that region still remains in “severe” drought or worse, thanks to the long-term drought that began last year. Overall, few changes were made to the drought areas in the Dakotas and northern Nebraska.

Although heavy rain fell in parts of the Northeast and Mid-Atlantic states this week, most of it fell after the Drought Monitor’s Tuesday cutoff, so the effects of that rain won’t be taken into account until next week. In the meantime, parts of the Northeast from West Virginia to Maine have been abnormally dry for the past several week. Parts of southern New England are suffering from 30-day and 60-day precipitation deficits, and patches of “moderate drought” developed in those regions last week. Fortunately, this is the time of year when streamflows can recover most quickly from a few soaking rains, so the effects of this long-term dryness may be eliminated with a few more storms in the coming weeks.

The latest Seasonal Drought Outlook, released on May 2, calls for the drought to continue to intensify in the West and Southwest, and improve in Florida and the Midwest.

Greenland’s Ice Loss May Slow, But Coasts Still At Risk

2013-05-08T17:00:35+00:00

The flow of Greenland’s glaciers toward the sea may have increased significantly in the past decade, but a new report in Nature finds that rate of increase is unlikely to continue. “The loss of ice has doubled in the past 10 years, but that doesn't mean it's going to double again in the next ten years,” said lead author Faezeh Nick, a glaciologist at the University Centre in Svalbard, in Longyearbyen, Norway, in an interview.

That conclusion, based on a new, sophisticated computer model, makes the worst-case scenario of sea level rise — an increase of 6 feet or so, on average, by 2100 — look less likely to play out.

Since the heat-trapping gas that has already put into the atmosphere will be there for hundreds of years to come, Greenland will continue to melt indefinitely. The fact that it may not happen quite as fast as the worst-case scenarios might forecast isn’t all that reassuring.
Credit: flickr/Howard Ignatius

That’s the good news. The bad news is that, in the model at least, the slowdown doesn’t necessarily bring glaciers back to their original, stately rate of flow. And since the heat-trapping gas that has already put into the atmosphere will be there for hundreds of years to come, Greenland will continue to melt indefinitely. The fact that it may not happen quite as fast as the worst-case scenarios might forecast isn’t all that reassuring.

Because even if sea level goes up by only half that much, the combination of rising seas and periodic storm surges could devastate coastal areas around the world. Scientists have concluded, based on earlier studies, that the lower figure of about 3 feet is most likely, and while that research didn’t explicitly calculate anticipated sea level rise, it appears consistent with those estimates.

Earlier studies, based on satellite observations, had also noted that Greenland’s ice flow has started to slow, which means the dumping of icebergs into the ocean should slow as well. Projecting what’s likely in the future, however, is the province not of observations but of models. In this case, Nick and a half-dozen colleagues used a new model that factors in the effects of climate change on both the air above Greenland and on the ocean below.

Those effects, Nick said, depend on the characteristics of individual glaciers. The Petermann glacier in northwest Greenland, for example — one of four the scientists modeled — “has a very long floating shelf, so it’s very sensitive to ocean warming.” As a result, the Petermann has loosed two massive “ice islands” into the sea, one in 2010 that was four times the size of Manhattan, and another, about half as big, in 2012.

But while those were major events, they didn’t affect the Petermann’s overall flow rate significantly. Other glaciers, such as the Jacobshavn, respond to warmer seas not just by letting loose big chunks of ice, but also by flowing more quickly. The reason: Jacobshavn’s ice was mostly grounded on the sea floor, not floating, creating tremendous friction that kept the upstream parts of the glacier in check. When that grounded ice is removed, it’s as though the brakes suddenly came off.

Even if sea level goes up by only half as much originally anticipated, the combination of rising seas and periodic storm surges could devastate coastal areas around the world.
Credit: flickr/Bruno Sanchez-Andrade Nuño

Warmer air temperatures, meanwhile, melt ice on top of the glaciers, and on the massive ice sheet they flow out of. In the summer of 2012, in fact, for the first time in more than a century, virtually the entire surface was at least partially melting for a few days in July (the reason, some scientists believe, was not just warmer-than-normal air temperatures overall, but also the heat-trapping effect of thin clouds).

Eventually, all of this water flows to the sea, but along the way it funnels down into crevasses in the ice, which can help lubricate the ice-rock interface at the bottom, letting glaciers flow faster. Downflowing water can also widen cracks in the ice, Nick said, which can enhance disintegration of the glacier’s leading edge already weakened by the warming ocean.

Feeding all of these effects into their model, the scientists found that speedup in the flow of glaciers into the sea is something to be expected in a generally warming climate, but that it won’t simply get more and more pronounced. “You see a big jump,” Nick said, “and then it slows down again.”

Editor's Note: The headline of this article has been changed to reflect the fact that the study concerns projections of future glacier melt rates, and not, as the previous study indicated, observations of a recent slowdown.

Hawaii at Growing Risk of Hurricanes, Studies Show

2013-05-08T12:29:34+00:00

Despite living in the middle of the tropical Pacific Ocean, Hawaiians haven’t had to worry much about hurricanes, thanks to prevailing ocean currents and weather patterns that typically deflect or weaken storms before they make landfall. But according to a new study, that may soon change in ways that could have far-reaching consequences for Hawaii’s military, transportation and energy infrastructure, as well as its tourism industry, the lifeblood of the islands. All would be extraordinarily vulnerable to sea level rise and storm surge-related flooding.

Damage to a structure in Kauai caused by Hurricane Iniki in 1992.
Credit: Wikimedia Commons via FEMA.

The new study, published in the journal Nature Climate Change, found that environmental conditions will become more favorable for tropical cyclones in and around the Hawaiian islands by 2075-2099. That’s due, in part, to a northwestward shift in the tropical cyclone track as well as increased ocean temperatures in the central tropical Pacific, which will help alter weather patterns.

Currently, tropical storms and hurricanes tend to curve out to sea well south and east of Hawaii after spinning up off the west coast of Mexico or in the Central Pacific. Hawaii has been affected by only eight named storms since 1979. The last big one was 1992’s Hurricane Iniki, which dealt a severe blow to the island of Kauai, but missed the more heavily populated and strategically important island of Oahu.

The possibility that future storms may threaten Hawaii has given pause not just to scientists, but policy makers as well.

Hypothetical scenarios of a hurricane reaching landfall near Honolulu have been presented to military officials and civilian policy makers in recent years, most recently at a 2012 workshop at the University of Hawaii. Those scenarios show potentially devastating consequences for Hawaii’s main port, military hub, energy facility, and tourism industry. Most of these facilities are located barely above sea level, making them vulnerable to storm surge as well as long-term sea level rise.

“Under direct-impact scenarios, there is the potential for much of Honolulu and most of Waikiki to be inundated,” said a 2012 study on potential storm-surge impacts on Hawaii, which was published in the journal Ocean Modeling. The study projected flooding up to several kilometers inland in the famous tourist destination of Waikiki Beach, much of which was built from drained marshlands.

Hawaii’s main oil refinery, located at Barbers Point, is situated in one of the lowest-lying areas on Oahu. “If you lose that, you essentially lose most of your energy,” said Chad Briggs, strategy director for Global Interconnections LLC, who helped lead the 2012 workshop while consulting for the U.S. Air Force, and has conducted scenario-planning exercises and research for the Department of Energy.

Briggs said a more diverse energy portfolio, which includes renewable energy sources, could improve Hawaii’s ability to withstand major storms without widespread energy disruptions.

The reef runway at Honolulu International Airport, on the island of Oahu.
Credit: Wikimedia Commons.

Another key at-risk facility is Honolulu International Airport, the island’s primary connection to the mainland and Asia. The airport features a 2-mile long runway built on an offshore reef, which a 2012 study predicted would be underwater if a strong hurricane made a direct hit on Honolulu.

Briggs said the main container port on Sand Island in Honolulu is also extremely vulnerable to flooding, which would disrupt food imports. “If you have a big storm surge you are going to lose that port,” Briggs said.

That could quickly cause food shortages, since Hawaii only has about a 3- to 5-day food stockpile, he said, relying as other areas do on “just-in-time delivery.”

The military, which could withstand a severe storm by sending its aircraft and ships away from the islands ahead of time, might be forced to aid island residents with food and gas deliveries as well as search and rescue operations while temporarily based on other islands due to damage at its normal bases, something they may not have trained for.

Briggs said a hurricane striking Honolulu head on isn’t really the worst-case scenario, either. Many more vulnerabilities can be brought to light by combining threats in unexpected ways, which more accurately represent real-world events. For example, he said scenario planning showed that Hawaii is especially susceptible to damage from a 1-2 punch of a tropical storm or hurricane followed in rapid succession by another storm, or by another very real threat to Hawaiians — a tsunami generated by a Pacific Rim earthquake.

While the new study, which was conducted by researchers based in Japan, Hawaii, and China using high-resolution computer models, projects a significant increase in the frequency of storms that may threaten Hawaii, the overall number of storms will still be lower than many other hurricane-prone regions of the U.S. For example, Florida was hit by four hurricanes during the 2004 hurricane season alone.

Scientists Develop New Way of Classifying Hurricanes

2013-05-07T12:30:27+00:00

For the past 40 years, the Saffir-Simpson Scale has been used to neatly classify all hurricanes into five categories. The scale, created by Herbert Saffir and Robert Simpson in the early 70s, is simple. It measures a storm’s maximum sustained wind speed — no more, no less. Its limitations – the biggest being that it does not account for the size of a storm’s wind field and its capacity to cause coastal inundation at landfall – have spurred scientists to develop a more comprehensive index.

Hurricane Sandy had a massive tropical storm force wind field that at one point spanned the entire East Coast from North Carolina to Massachusetts.
Credit: National Hurricane Center.

Saffir-Simpson’s limitations were brought to the forefront last October by Hurricane Sandy, which briefly reached a maximum intensity of Category 3, and weakened to a Category 1 storm closer to landfall. That minimal hurricane classification may have led some to downplay its destructive potential, a perception that proved dead wrong when the storm made landfall — technically as a post-tropical cyclone at that point — pushing a record-high storm surge onto the Jersey Shore and into New York Harbor, and flooding low-lying areas.

Had people known ahead of time that Sandy’s size and energy were far more powerful than even 2005’s Hurricane Katrina, they might have prepared for the storm differently.

Now, a new study, published in the journal Monthly Weather Review by scientists from Florida State University, proposes a new metric that aims to complement Saffir-Simpson and other recently developed scales by taking into account a storm’s intensity, duration, and size. The metric, known as “Track Integrated Kinetic Energy,” or TIKE, builds from an existing measure of storm integrated kinetic energy (IKE), which was developed in 2007.

This would help augment the Accumulated Cyclone Energy (ACE) index, for example, and the Power Dissipation Index (PDI), both of which seek to describe the amount of energy expended by a tropical storm or hurricane. The biggest benefit of the new TIKE index is that it could raise the alarm for storm surge risk at a time when sea levels are rising and coastal population is soaring. It may also help scientists detect trends in storm size, which may be related to warming sea and air temperatures.

The IKE metric incorporates the ability of a hurricane’s winds to set ocean water into motion, via waves and storm surge, while also measuring how the storm’s winds would affect structures in its path. The TIKE metric expands the IKE concept by adding IKE measurements over the lifespan of a tropical cyclone, as well as over all named tropical cyclones in the hurricane season.

The new study looked at the seasonal and year-to-year variations in Atlantic Ocean tropical cyclone activity during the period from 1990-2011, a period of reliable storm observations, and found that the storms with the highest TIKE values tend to form in the eastern tropical Atlantic. September, which tends to be the busiest month for tropical storms and hurricanes, is also the peak month on the TIKE index, the study found, with the greatest frequency of large storms.

Coastal homes in Texas' Bolivar Peninsula were wiped out by the storm surge from Hurricane Ike in 2008.
Credit: NOAA.

However, during the month of October — which is when Hurricane Sandy struck the U.S. — there tends to be an uptick in the number of particularly large, long-duration storms closer to the western Atlantic, the study found.

Vasu Misra, the lead author of the study and an associate professor of meteorology in the Department of Earth, Ocean and Atmospheric Science at FSU, said recent storms, such as Hurricane Ike in 2008 and Hurricane Sandy, have shown that damages from coastal flooding far exceed the wind damage caused by these storms, and that the size of a storm’s wind field helps determine the height of the storm surge.

“Existing metrics overemphasize the intensity part which is based solely on wind speeds,” Misra said in an interview.

Both Ike and Sandy were exceptionally large hurricanes. In fact, Sandy set a record for having the largest wind field of any hurricane on record, with a diameter of about 900 miles at one point.

“The swath of [Hurricane Sandy’s] very strong winds along the coastline was huge, and it produced a huge amount of inundation along the coast,” Misra said.

According to Misra, Hurricane Sandy had a higher TIKE value than any other tropical storm or hurricane in the North Atlantic Ocean Basin since 1990. Hurricane Lily, which occurred in 1996, was the runner-up, followed by 2010’s Igor, 1995’s Luis, 1997’s Erica, and Hurricane Olga, which occurred in 2001.

Consistent with other research, the study found that La Niña events, which feature cooler-than-average water temperatures in the tropical Pacific Ocean, tend to be associated with hurricane seasons with large TIKE values, as do warmer-than-average conditions in the central and northern Atlantic Ocean.

Misra and his colleagues hope to develop the capability of predicting TIKE values for an entire season, which could be useful for coastal residents and officials, and a welcome addition considering the lessons from Hurricane Sandy.

Editor's Note: This story has been revised to indicate that Hurricane Sandy briefly reached Category 3 intensity, not Category 2 intensity as originally indicated. This is according to a post-event analysis conducted by NOAA.