Climate Change

Welcome to the Climate Change Blog!

noreply@blogger.com (Allen) — Fri, 06 Dec 2013 17:39:00 +0000

Note: I have been collecting scientific articles about climate change, and, because of constraints on my time, I have decided to stop collecting articles. I have a lot of articles documented in this blog. Scientists are coming to the realization that natural caused are important as a cause of climate change. Persons favoring natural causes are coming to the realization that humans are an important cause of climate change. Time will tell which way the debate goes. If you have serious concerns about climate change, please leave your comments on appropriate pages, and I will respond to the comments, as appropriate. AWL 12/6/2013

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People have been arguing for decades about climate change. Some say changes in our climate are natural and are nothing for us to worry about. Others say changes are due to man-made emissions and that, to preserve our climate and possibly life on earth, we must reduce those emissions. Many of the arguments are based on emotional feelings with little basis in factual information.

In order to provide some degree of sanity in these discussions, I have created this blog in which results of scientific research are given. Links to new scientific reports are made via additions to existing posts, although new posts will be created if appropriate posts for the new information do not exist. At the top of each page are navigational links to various categories. All of the posts in this blog are in those categories, and by clicking a category-link, you will get a page that links to the posts that pertain to that category. The Site Map page has links to all of the pages in the site.

This blog does not take a position about climate change. I hope you will read the reports about scientific research and form reasonable conclusions about Climate Change. In addition, you are invited to share your viewpoints via comments to the posts!

Science Manipulation of Climate

noreply@blogger.com (Allen) — Thu, 20 Dec 2012 16:41:00 +0000

Many people are debating the causes of climate change. Some scientists who believe climate change is real suggest that our environment be manipulated to reduce the effects of climate change. This post is tracking suggestions by scientists for the geo-engineering of our climate.

Geoengineering, the use of human technologies to alter Earth's climate system -- such as injecting reflective particles into the upper atmosphere to scatter incoming sunlight back to space -- has emerged as a potentially promising way to mitigate the impacts of climate change. But such efforts could present unforeseen new risks. That inherent tension, argue two professors from UCLA and Harvard, has thwarted both scientific advances and the development of an international framework for regulating and guiding geoengineering research.

Numerous geo-engineering schemes have been suggested as possible ways to reduce levels of the greenhouse gas carbon dioxide in the atmosphere and so reduce the risk of global warming and climate change. One such technology involves dispersing large quantities of iron salts in the oceans to fertilize otherwise barren parts of the sea and trigger the growth of algal blooms and other photosynthesizing marine life. Photosynthesis requires carbon dioxide as its feedstock and when the algae die they will sink to the bottom of the sea taking the locked in carbon with them.

But a University of Iowa law professor believes the legal ramifications of this kind of geo-engineering need to be thought through in advance and a global governance structure put in place soon to oversee these efforts.

Natural Causes of Climate Change

noreply@blogger.com (Allen) — Thu, 18 Oct 2012 17:13:00 +0000

This page discusses natural causes of climate change.

The Greenland ice sheet is melting from below, caused by a high heat flow from the mantle into the lithosphere. This influence is very variable spatially and has its origin in an exceptionally thin lithosphere. Consequently, there is an increased heat flow from the mantle and a complex interplay between this geothermal heating and the Greenland ice sheet. The international research initiative IceGeoHeat led by the GFZ German Research Centre for Geosciences establishes in the current online issue of Nature Geoscience that this effect cannot be neglected when modeling the ice sheet as part of a climate study.

Natural swings in the climate have significantly intensified Northern Hemisphere monsoon rainfall, showing that these swings must be taken into account for climate predictions in the coming decades, a new study finds.

One important factor in climate change is natural causes, that is, aspects of our earth, other than effects of people, that affect our climate. Natural causes of climate change include the earth itself, winds, volcanoes, and ocean currents. Most of these factors are discussed in other posts. This post contains links to factors affecting climate changes that are not discussed in other places.
Ancient rises in sea levels and global warming are partially attributable to cyclical activity below Earth's surface, researchers from New York University and Ottawa's Carleton University have concluded in an analysis of geological studies.

However, the article's authors, NYU's Michael Rampino and Carleton University's Andreas Prokoph, note that changes spurred by Earth's interior are gradual, taking place in periods ranging from 60 million to 140 million years -- far less rapidly than those brought on by human activity.

A team led by the University of Colorado Boulder looking for clues about why Earth did not warm as much as scientists expected between 2000 and 2010 now thinks the culprits are hiding in plain sight -- dozens of volcanoes spewing sulfur dioxide.

"We have shown that adding polar storms into computer-generated models of the ocean results in significant changes in ocean circulation -- including an increase in heat traveling north in the Atlantic Ocean and more overturning in the Sub-polar seas.

Lead author, Dr Paul Holland of BAS says: "Until now these changes in ice drift were only speculated upon, using computer models of Antarctic winds. This study of direct satellite observations shows the complexity of climate change. The total Antarctic sea-ice cover is increasing slowly, but individual regions are actually experiencing much larger gains and losses that are almost offsetting each other overall. We now know that these regional changes are caused by changes in the winds, which in turn affect the ice cover through changes in both ice drift and air temperature. The changes in ice drift also suggest large changes in the ocean surrounding Antarctica, which is very sensitive to the cold and salty water produced by sea-ice growth.

"In the temperature curves from the ice cores we can see that there is no general global cooling as a result of the eruption. There is certainly a cooling and large fluctuations in temperature in the northern hemisphere, but it becomes warmer in the southern hemisphere, so the global cooling has been short," says Anders Svensson.

Reports of declining ice coverage and drowning polar bears in the Arctic illustrate dramatic ecosystem responses to global climate change in Earth's polar regions. But in this first-ever account of a long-term project in the southern Caribbean, a Stony Brook professor and his colleagues report in this week's Proceedings of the National Academy of Sciences that tropical ecosystems are also affected by global climatic trends -- and with accompanying economic impacts.

Lead author Dr Stewart Jamieson, a glaciologist at the Department of Geography, Durham University, said: "Our research shows that the physical shape of the channels is a more important factor in controlling ice stability than was previously realised. Channel width can have a major effect on ice flow, and determines how fast retreat, and therefore sea-level rise, can happen.

Site Map of Climate Change

noreply@blogger.com (Allen) — Thu, 04 Oct 2012 07:05:00 +0000

This page is a site map of the Climate Change web site. It gives the search engines a page that has all internal links, and it contributes to easy navigation of the site by serving as an index to the site.

Antarctica
Ice-Melt
Deep Water

Arctic
Ice-Melt
Northeast Passage

Debates
Climate Change
Denier's Lists

Emissions
CO2
Methane
Other Emissions

Geoengineering
Science Manipulation

Greenland
Climate Changes In Greenland

Models
Climate Models

Natural Causes
Natural Causes

Oceans
The Influence of Oceans

Sky
Climate Change and the Sky

Sun
The Influence of the Sun

Temperature
Animals and Vegetation
Glaciers and Sea-Ice
Other Effects

Weather
Climate Change and Weather

Climate Models

noreply@blogger.com (Allen) — Sat, 22 Sep 2012 18:34:00 +0000

An important aspect of climate scientists is the creation of models that give approximations of our climate. These models allow scientists to understand current climate conditions and to predict future climate conditions. This page gives links to scientific research about climate models.

They found a fairly high degree of consensus on the general character of the pace of climate change. In response to an instantaneous increase in greenhouse gas emissions, climate change is fast out of the starting gate but then slows down, and takes a long time to approach the finish line.
There is substantial quantitative disagreement among climate models, however. For example, one model reaches 38 percent of the maximum warming in the first decade after a step increase in CO2 concentration, while another model reaches 61 percent of the maximum warming in this time period. Similarly, one model reaches only 60 percent of maximum warming in the first century after the step increase, while another achieves 86 percent of maximum warming during this interval.

Scientists from UC Irvine and the National Center for Atmospheric Research have developed a new computer model to measure global warming's effect on soil worldwide that accounts for how bacteria and fungi in soil control carbon.

New research findings from the Centre for Permafrost (CENPERM) at the Department of Geosciences and Natural Resource Management, University of Copenhagen, document that permafrost during thawing may result in a substantial release of carbon dioxide into the atmosphere and that the future water content in the soil is crucial to predict the effect of permafrost thawing. The findings may lead to more accurate climate models in the future.

"The fact that we are experiencing more fires and that climate change may increase fire frequency underscores the need to include these specialized particles in the computer models, and our results show how this can be done," Dubey said.

Only a few climate models were able to reproduce the observed changes in extreme precipitation in China over the last 50 years. This is the finding of a doctoral thesis from the University of Gothenburg, Sweden.

It seems counterintuitive that clouds over the Southern Ocean, which circles Antarctica, would cause rain in Zambia or the tropical island of Java. But new research finds that one of the most persistent biases in global climate models -- a phantom band of rainfall just south of the equator that does not occur in reality -- is caused by poor simulation of the cloud cover thousands of miles farther to the south.

Researchers rely on models that use estimated ice thickness data and simulated atmospheric conditions to forecast how sea ice will change during the summer. For the first time, near real-time ice thickness data obtained by NASA's Operation IceBridge has been used to correct a forecast model's initial measurements, which could lead to improved seasonal predictions.

"We have shown that adding polar storms into computer-generated models of the ocean results in significant changes in ocean circulation -- including an increase in heat traveling north in the Atlantic Ocean and more overturning in the Sub-polar seas.

The researchers tested their approach on data originally taken in 1996 and 1997 in the Labrador Sea, an arm of the North Atlantic Ocean that lies between Greenland and Canada. They included satellite observations of ice cover, as well as local readings of wind speed, water and air temperature, and water salinity. The approach produced a tight fit between simulated and observed sea-ice and ocean conditions in the Labrador Sea -- a large improvement over existing models.

"New climate models will have to take these findings into account," says Professor Dr. Thorsten Hoffmann of the Institute of Inorganic Chemistry and Analytical Chemistry at Johannes Gutenberg University Mainz (JGU) in Germany. The Mainz researchers contributed primarily to the development of analytical techniques for studying the chemical composition of the aerosol particles in the Muchachas project. Thanks to their development of so-called 'soft ionization' techniques and the corresponding mass spectrometers, Hoffmann's work group was able to track the concentration of individual molecule species in the atmospheric simulation chamber and thus observe the chemical aging of the atmospheric aerosols at the molecular level. It was clearly demonstrated that oxidation occurred in the gaseous phase and not in the particle phase. "Now the goal is to integrate these underlying reactions in models of regional and global atmospheric chemistry and so reduce the discrepancy between the expected and the actually observed concentrations of organic aerosol particles," explains Hoffmann.

Climate-prediction models show skills in forecasting climate trends over time spans of greater than 30 years and at the geographical scale of continents, but they deteriorate when applied to shorter time frames and smaller geographical regions, a new study has found.

The findings do not change broader concerns about global warming. Temperatures are still projected to increase about four to 11 degrees by the end of this century, and the study actually confirms that some of the world’s most sophisticated climate models are accurate.

In the 1990s, observations did not show the troposphere, particularly in the tropics, to be warming, even though surface temperatures were rapidly warming. This lack of tropospheric warming was used by some to question both the reality of the surface warming trend and the reliability of climate models as tools. This new paper extensively reviews the relevant scientific analyses — 195 cited papers, model results and atmospheric data sets — and finds that there is no longer evidence for a fundamental discrepancy and that the troposphere is warming.

One popular climate record that shows a slower atmospheric warming trend than other studies contains a data calibration problem, and when the problem is corrected the results fall in line with other records and climate models, according to a new University of Washington study.

"One of the criticisms from climate-change skeptics is that different climate models give different results, so they argue that they don't know what to believe," he said. "We wanted to develop a way to determine the likelihood of different outcomes, and combine them into a consensus climate projection. We show that there are shared conclusions upon which scientists can agree with some certainty, and we are able to statistically quantify that certainty."

Climate Change and Weather

noreply@blogger.com (Allen) — Mon, 27 Aug 2012 18:20:00 +0000

Scientists are investigating various aspects of climate change. One aspect that is getting a lot of attention from scientists is our weather. It is important that we understand how and why weather changes occur, because we all are affected by weather.

Here are links to some of the research about weather.

A new survey commissioned by the Stanford Woods Institute for the Environment and the Center for Ocean Solutions finds that an overwhelming majority of Americans want to prepare in order to minimize the damage likely to be caused by global warming-induced sea-level rise and storms.

Molina emphasized that there is no "absolute certainty" that global warming is causing extreme weather events. But he said that scientific insights during the last year or so strengthen the link. Even if the scientific evidence continues to fall short of the absolute certainly measure, the heat, drought, severe storms and other weather extremes may prove beneficial in making the public more aware of global warming and the need for action, said Molina.

Other Factors

noreply@blogger.com (Allen) — Thu, 02 Aug 2012 14:40:00 +0000

The Antarctic is of special interest to scientists because it is a large area that affects the climate of the earth. Here are links to some of their research.

By carefully analyzing a 150-year-old moss bank on the Antarctic Peninsula, researchers reporting in Current Biology, a Cell Press publication, on August 29 describe an unprecedented rate of ecological change since the 1960s driven by warming temperatures.

The average area covered by the Antarctic ozone hole this year was the second smallest in the last 20 years, according to data from NASA and National Oceanic and Atmospheric Administration (NOAA) satellites. Scientists attribute the change to warmer temperatures in the Antarctic lower stratosphere.

Given the predicted rise in global temperatures in the coming decades, climate scientists are particularly interested in warm periods that occurred in the geological past. Knowledge of past episodes of global warmth can be used to better understand the relationship between climate change, variations in atmospheric carbon dioxide and the reaction of Earth’s biosphere. An international team led by scientists from the Goethe University and the Biodiversity and Climate Research Centre in Frankfurt, Germany, has discovered an intense warming phase around 52 million years ago in drill cores obtained from the seafloor near Antarctica — a region that is especially important in climate research.

The first comprehensive reconstruction of a 15,000 year climate history from an ice core collected from James Ross Island in the Antarctic Peninsula region is reported this week in the journal Nature. The scientists reveal that the rapid warming of this region over the last 100 years has been unprecedented and came on top of a slower natural climate warming that began around 600 years ago. These centuries of continual warming meant that by the time the unusual recent warming began, the Antarctic Peninsula ice shelves were already poised for the dramatic break-ups observed from the 1990's onwards.

Effects of Temperature on Climate Change

noreply@blogger.com (Allen) — Tue, 26 Jun 2012 19:18:00 +0000

Climate change means one thing: temperatures are changing. For centuries the climates of the earth have been relatively constant. After Spring comes Summer. After Summer comes Fall and then Winter. These changes of seasons occur at approximately the same dates each year. However, in recent years, the changes of season have occurred at different dates. Some areas of the earth are hotter while other areas are colder. Something is occurring that causes these changes in the seasons. Scientists and politicians are trying to understand what is causing our climate to change. One of the parameters that scientists use to recognize that our climate is changing is *temperature*.

This page gives links to pages that discuss temperature.

Animals and Vegetation

Glaciers and Sea-Ice

Other Effects

Effects of Climate Change on Glaciers and Sea-Ice

noreply@blogger.com (Allen) — Tue, 26 Jun 2012 19:10:00 +0000

One noticeable effect of increases in temperature is decreases in the ice content of glaciers and sea-ice. Increases in temperature might be due to climate change triggered by human intervention or triggered by natural events. This page gives links to scientific articles that discusses decreases in ice level.

Researchers taking a new look at the snow and ice covering Mount Everest and the national park that surrounds it are finding abundant evidence that the world's tallest peak is shedding its frozen cloak. The scientists have also been studying temperature and precipitation trends in the area and found that the Everest region has been warming while snowfall has been declining since the early 1990s.

Since their maximum extension, reached between 1650 and 1750, during the Little Ice Age*, the tropical Andean glaciers have gradually retreated. Over the last 30 years, however, their decline has taken dramatic proportions. This summary clearly shows the peculiarity of these last decades, with melting speeds that had never been reached before in 300 years: the surface areas of glaciers in Colombia, Ecuador, Peru and Bolivia were reduced from 30-50% since the end of the 1970s and up to 80-100% in extreme cases. This new study confirms the acceleration of climate change in this part of the world at the end of the 20th century.

The planet's two largest ice sheets have been losing ice faster during the past decade, causing widespread confusion and concern. A new international study provides a firmer read on the state of continental ice sheets and how much they are contributing to sea-level rise.

The forecast by Brigham Young University geology professor Summer Rupper comes after her research on Bhutan, a region in the bull's-eye of the monsoonal Himalayas. Published in Geophysical Research Letters, Rupper's most conservative findings indicate that even if climate remained steady, almost 10 percent of Bhutan's glaciers would vanish within the next few decades. What's more, the amount of melt water coming off these glaciers could drop by 30 percent.

Sea levels are rising faster than expected from global warming, and University of Colorado geologist Bill Hay has a good idea why. The last official IPCC report in 2007 projected a global sea level rise between 0.2 and 0.5 meters by the year 2100. But current sea-level rise measurements meet or exceed the high end of that range and suggest a rise of one meter or more by the end of the century.

Glaciers in the eastern and central regions of the Himalayas appear to be retreating at accelerating rates, similar to those in other areas of the world, while glaciers in the western Himalayas are more stable and could be growing, says a new report from the National Research Council.

"This continues the trend in accelerated ice loss during the past two and a half decades and brings the total loss since 1980 to more than 10.5 metres of water equivalent," said Professor Haberli. During 1980-1999, average loss rates had been 0.3 metres per year. Since the turn of the millennium, this rate had increased to about half a metre per year.

The Montana park has 26 named glaciers today, down from 150 in 1850. Those that remain are typically mere remnants of their former frozen selves, a new gallery of before and after images reveals.

Photographs taken by members of a WWF expedition to the Ruwenzoris last month show a massive reduction in glacier size when compared with similar images from the 1950s, probably from increased temperatures or humidity.

A revised outlook for the Arctic 2008 summer sea ice minimum shows ice extent will be below the 2005 level but not likely to beat the 2007 record. DAMOCLES will dispatch eleven research missions into the Arctic this autumn to better understand the future of the sea ice.

Project MARGO offers more exhaustive data than that available at present and will serve to represent more exact models of the past and predict the climate's evolution in the future. In addition, MARGO has enabled researchers to discover new aspects of the Last Glacial Maximum, such as the fact that the ice covering the Northern Atlantic Ocean and extending down to the British Isles was not permanent but actually melted in the warmer months to a much larger extent than it does now.

The new still tentative data of more than 80 glaciers confirm the global trend of fast ice loss since 1980. Glaciers with long-term observation series (30 glaciers in 9 mountain ranges) have experienced a reduction in total thickness of more than 11 m w.e. until 2007. The average annual ice loss during 1980-1999 was roughly 0.3 m w.e. per year. Since 2000, this rate has increased to about 0.7 m w.e. per year.

A three-year study, to be used by the China Geological Survey Institute, shows that glaciers in the Yangtze source area, central to the Qinghai-Tibet plateau in south-western China, have receded 196 square kilometres over the past 40 years.
Glaciers at the headwaters of the Yangtze, China’s longest river, now cover 1,051 square kilometres compared to 1,247 square kilometres in 1971, a loss of nearly a billion cubic metres of water, while the tongue of the Yuzhu glacier, the highest in the Kunlun Mountains fell by 1,500 metres over the same period.

Look at Washington State. The Nisqually Glacier on Mt. Rainier is growing. The Emmons Glacier on Mt. Rainier is growing. Glaciers on Glacier Peak in northern Washington are growing. And Crater Glacier on Mt. Saint Helens is now larger than it was before the 1980 eruption. (I don't think all of the glaciers in Washington or Alaska are being monitored either.)

Glaciation of Earth also occurs every 100,000 years. Lisiecki found that the timing of changes in climate and eccentricity coincided. "The clear correlation between the timing of the change in orbit and the change in the Earth's climate is strong evidence of a link between the two," said Lisiecki. "It is unlikely that these events would not be related to one another."

The Tibetan Plateau is the largest and highest mountain region on Earth with glaciers whose meltwater provides the water supply for more than 1.3 billion people through several of the largest rivers in Asia. In a thesis in Physical Geography from Stockholm University, Jakob Heyman shows that the glaciers in Tibet have remained relatively small and have not been much larger than today for tens of thousands to hundreds of thousands of years back in time.

The researchers proceeded to analyze a series of measurements based on many parameters related to climate, glaciers, and streamflow in order to compare this data with existing information. Although these studies have revealed a clear tendency toward a reduction in streamflow during the summer, the impact of melting glaciers on the annual flow remains unclear. "Many factors can have an influence on water quantity," explains Annina Sorg. "Precipitation level, evaporation, and even human interference on the hydrological cycle are all factors to consider."

Effects of Climate Change On Animals and Vegetation

noreply@blogger.com (Allen) — Tue, 26 Jun 2012 19:02:00 +0000

This page gives links to pages that discuss changes in the growth and behavior of plants and animals due to temperature.

Scientists expect climate change and warmer oceans to push the fish that people rely on for food and income into new territory. Predictions of where and when species will relocate, however, are based on broad expectations about how animals will move and have often not played out in nature. New research based at Princeton University shows that the trick to more precise forecasts is to follow local temperature changes.

Comparing plant communities today with a survey taken 50 years ago, a UA-led research team is providing the first on-the-ground evidence for Southwestern plants being pushed to higher elevations by an increasingly warmer and drier climate.

In a new study, Boston University researchers and collaborators have found that butterflies show signs of being affected by climate change in a way similar to plants and bees, but not birds, in the Northeast United States. The researchers focused on Massachusetts butterfly flight periods, comparing current flight periods with patterns going back more than 100 years using museum collections and the records of dedicated citizen scientists. Their findings indicate that butterflies are flying earlier in warmer years.

Using the meticulous phenological records of two iconic American naturalists, Henry David Thoreau and Aldo Leopold, scientists have demonstrated that native plants in the eastern United States are flowering as much as a month earlier in response to a warming climate.

Much biological research on climate change focuses on the impacts of warming and changes in precipitation over wide areas. Researchers are now increasingly recognizing that at the local scale they must understand the effects of climate change through the intertwined patterns of soils, vegetation, and water flowpaths -- not forgetting the uses humans have made of the landscape.

Some high mountain meadows in the Pacific Northwest are declining rapidly due to climate change, a study suggests, as reduced snowpacks, longer growing seasons and other factors allow trees to invade these unique ecosystems that once were carpeted with grasses, shrubs and wildflowers.

Malaria has been found in birds in parts of Alaska, and global climate change will drive it even farther north, according to a new study published September 19 in the journal PLoS ONE.

Coral reefs face severe challenges even if global warming is restricted to the 2 degrees Celsius commonly perceived as safe for many natural and human-made systems. Warmer sea surface temperatures are likely to trigger more frequent and more intense mass coral bleaching events. Only under a scenario with strong action on mitigating greenhouse-gas emissions and the assumption that corals can adapt at extremely rapid rates, could two thirds of them be safe, shows a study now published in Nature Climate Change. Otherwise all coral reefs are expected to be subject to severe degradation.

Scientists have detected signs that the planet's tropics may have expanded much farther north in the past 3 decades than climate models had predicted for the next century. If the findings are confirmed and the trend continues, it could place major strains on subtropical ecosystems, hasten the spread of tropical diseases, and generally make life less pleasant for populations living with the zones of change.

Earth’s tropical belt seems to have expanded a couple hundred miles over the past quarter century, which could mean more arid weather for some already dry subtropical regions, new climate research shows.

A huge “migration” of trees has begun across much of the West due to global warming, insect attack, diseases and fire, and many tree species are projected to decline or die out in regions where they have been present for centuries, while others move in and replace them.

Over the last century, the temperature has risen by more than one degree. The cooling trend over several thousand years is broken, and this has triggered changes in flora, fauna, and landscapes. In important respects, the present state is similar to what occurred directly after the latest ice age.

Many wild plant species thought to be "stable" in the face of climate change are actually responding to global warming, say researchers at UC Santa Barbara's National Center for Ecological Analysis and Synthesis (NCEAS). Their findings, in a study titled, "Divergent responses to spring and winter warming drive community level flowering trends," are published in the Proceedings of the National Academy of Sciences.

The researchers found that butterfly species which already tend to emerge later in the year or fly higher in the mountains have evolved to deal with a shorter window of opportunity to reproduce, and as a result may fare worse in a warming climate, compared to those that emerge over a longer time period.

The lily, a plant that grows best on subalpine slopes, is fast becoming a hothouse flower. In Earth's warming temperatures, its first blooms appear some 17 days earlier than they did in the 1970s, scientists David Inouye and Amy McKinney of the University of Maryland and colleagues have found.

Scientists from Finland and Oxford University investigated an area of 100,000 km2, known as the northwestern Eurasian tundra, stretching from western Siberia to Finland. Surveys of the vegetation, using data from satellite imaging, fieldwork, and expert observations from indigenous reindeer herders, showed that in 8-15% of the area willow (Salix) and alder (Alnus) plants have grown into trees over 2 metres in height in the last 30-40 years.

The study, which is the first of its kind in the world, highlights that plant species are already responding to changes in climate. The results are published online July 4 in the Royal Society journal Biology Letters.

Bauman and colleagues found that the decline in milk production due to climate change will vary across the U.S., since there are significant differences in humidity and how much the temperature swings between night and day across the country. For instance, the humidity and hot nights make the Southeast the most unfriendly place in the country for dairy cows.

The findings by University College Dublin scientists published in the journal Biology Letters suggest that rising soil temperatures due to climate change may be extending the geographical habitat range of the earthworm Prosellodrilus amplisetosus.

However, the mechanisms explaining species-specific responses to changes in temperature and water availability are most likely much more complex, according to researchers at Texas Tech University and the United States Geological Survey. After reexamining an upslope vegetation shift reported in a high-profile 2008 study published in Proceedings of the National Academy of Sciences, the pair refuted the findings that plants are moving upslope in California because of climate warming by studying one particular desert shrub.

Results from a decades-long research project show that mountain rodents called marmots are growing larger, healthier and more plentiful in response to climate change.

Climate change is causing a late wake-up call from hibernation for a species of Rocky Mountain ground squirrel and the effect is deadly.

Subtropical and warm-climate species such as the giant swallowtail and zabulon skipper -- many of which were rare or absent in Massachusetts as recently as the late 1980s -- show the sharpest increases. At the same time, more than three-quarters of northerly species (species with a range centered north of Boston) are now declining in Massachusetts, many of them rapidly. Most impacted are the species that overwinter as eggs or small larvae, indicating that these overwintering stages may be much more sensitive to drought or lack of snow cover.

Other Effects of Climate Change

noreply@blogger.com (Allen) — Tue, 26 Jun 2012 17:19:00 +0000

This page gives links to science articles that discuss the effects of changes in temperatures on the earth.

"The study did not seek to estimate how much the planet will warm, or how rapidly sea levels will rise," noted Peter Clark, an Oregon State University paleoclimatologist and author on the PNAS article. "Instead, we were trying to pin down the 'sea-level commitment' of global warming on a multi-millennial time scale. In other words, how much would sea levels rise over long periods of time for each degree the planet warms and holds that warmth?"

One often ignored consequence of global climate change is that the Northern Hemisphere is becoming warmer than the Southern Hemisphere, which could significantly alter tropical precipitation patterns, according to a new study by climatologists from the University of California, Berkeley, and the University of Washington, Seattle.

Using data from 73 sites around the world, scientists have been able to reconstruct Earth's temperature history back to the end of the last Ice Age, revealing that the planet today is warmer than it has been during 70 to 80 percent of the time over the last 11,300 years.

In 2012, the contiguous United States (CONUS) average annual temperature of 55.3°F was 3.2°F above the 20^th century average, and was the warmest year in the 1895-2012 period of record for the nation. The 2012 annual temperature was 1.0°F warmer than the previous record warm year of 1998. Since 1895, the CONUS has observed a long-term temperature increase of about 0.13°F per decade. Precipitation averaged across the CONUS in 2012 was 26.57 inches, which is 2.57 inches below the 20thcentury average. Precipitation totals in 2012 ranked as the 15^th driest year on record. Over the 118-year period of record, precipitation across the CONUS has increased at a rate of about 0.16 inch per decade.

The globally-averaged temperature for 2012 marked the 10^th warmest year since record keeping began in 1880. It also marked the 36^th consecutive year with a global temperature above the 20^th century average. The last below-average annual temperature was 1976. Including 2012, all 12 years to date in the 21^st century (2001-2012) rank among the 14 warmest in the 133-year period of record. Only one year during the 20^st century -- 1998 -- was warmer than 2012.

In the most comprehensive review of changes to extreme rainfall ever undertaken, researchers evaluated the association between extreme rainfall and atmospheric temperatures at more than 8000 weather gauging stations around the world.

"The last decade brought unprecedented heat waves; for instance in the US in 2012, in Russia in 2010, in Australia in 2009, and in Europe in 2003," lead-author Dim Coumou says. "Heat extremes are causing many deaths, major forest fires, and harvest losses -- societies and ecosystems are not adapted to ever new record-breaking temperatures." The new study relies on 131 years of monthly temperature data for more than 12,000 grid points around the world, provided by NASA. Comprehensive analysis reveals the increase in records.

According to NOAA scientists, 2012 marked the warmest year on record for the contiguous United States with the year consisting of a record warm spring, second warmest summer, fourth warmest winter and a warmer-than-average autumn. The average temperature for 2012 was 55.3°F, 3.2°F above the 20th century average, and 1.0°F above 1998, the previous warmest year.

CSIRO scientists Wenju Cai, Tim Cowan and Marcus Thatcher explored why autumn rainfall has been in decline across south-eastern Australia since the 1970s, a period that included the devastating Millennium drought from 1997-2009.

Research undertaken by the University of Southampton and its associates in Venice has revealed that the sea surface temperature (SST) in coastal regions is rising as much as ten times faster than the global average of 0.13 degrees per decade.
Researchers believe that this is partly as a result of a process known as the 'urban heat island effect'; where regions experiencing rapid industrial and urban expansion produce vast amounts of heat, making the area warmer than its surroundings.

Satellite measurement of sea surface temperatures has yielded clear evidence of major changes taking place in the waters of Australia's Great Barrier Reef over the past 25 years, marine scientists have found.

During the first six months of 2012, sea surface temperatures in the Northeast Shelf Large Marine Ecosystem were the highest ever recorded, according to the latest Ecosystem Advisory issued by NOAA's Northeast Fisheries Science Center (NEFSC). Above-average temperatures were found in all parts of the ecosystem, from the ocean bottom to the sea surface and across the region, and the above average temperatures extended beyond the shelf break front to the Gulf Stream.

Gardeners and landscapers may want to rethink their fall tree plantings. Warming temperatures have already made the U.S. Department of Agriculture's new cold-weather planting guidelines obsolete, according to Dr. Nir Krakauer, assistant professor of civil engineering in The City College of New York's Grove School of Engineering.

Hurricanes in the Atlantic are increasing because of natural weather patterns rather than global warming, a study has concluded. [posted by The Times (online) on June 7, 2007].

The IPCC’s fourth and final assessment of the climate change problem—known as the Synthesis Report—combines all of these reports and adds that “warming could lead to some impacts that are abrupt or irreversible, depending upon the rate and magnitude of the climate change.”

Warmer temperatures are only part of the problem, explained geographer Thomas Painter of the University of Utah, Salt Lake City, who presented his own research on snowpack in the West at the meeting. Also contributing is carbon black, known more commonly as soot, which continually rains down on the glaciers but tends to concentrate on the surface of the ice. By the calculations of his research team, Painter said, soot increases heat absorption from the sun's rays by 43%. That provides "yet another reason" to limit carbon black from industrial emissions, says climatologist Claire Parkinson of NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Duffy asked Marohasy: “Is the Earth still warming?” She replied: “No, actually, there has been cooling, if you take 1998 as your point of reference. If you take 2002 as your point of reference, then temperatures have plateaued. This is certainly not what you’d expect if carbon dioxide is driving temperature because carbon dioxide levels have been increasing but temperatures have actually been coming down over the last 10 years.”

A group of 3,146 earth scientists surveyed around the world overwhelmingly agree that in the past 200-plus years, mean global temperatures have been rising, and that human activity is a significant contributing factor in changing mean global temperatures.

Scientists from the Complutense University of Madrid (UCM) have selected 262 European observatories which analysed the series of minimum and maximum daily temperatures from 1955 to 1998 to estimate trend variations in extreme temperature events. According to the study, in Europe days of extreme cold are decreasing and days of extreme heat increasing. From 0.5ºC to 1ºC in the average minimum temperature, and from 0.5ºC to 2ºC in the average maximum temperature.

The Arctic and Antarctic regions are warming faster than previously thought, raising world sea levels and making drastic global climate change more likely than ever, international scientists said on Wednesday. [posted by NewsDaily on February 25, 2009]

“There’s always interest in the annual temperature numbers and a given year’s ranking, but the ranking often misses the point,” said James Hansen, GISS director. “There’s substantial year-to-year variability of global temperature caused by the tropical El Nino-La Nina cycle. When we average temperature over five or ten years to minimize that variability, we find global warming is continuing unabated.”

“The vast amount of heat stored in the ocean regulates Earth’s temperature, much as a flywheel regulates the speed of an engine,” said Bill Patzert, an oceanographer and climatologist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The ocean has a long history of capturing and giving up heat generated by both human activities and natural cycles; it is the thermal memory of the climate system.”

The GRL study took two years to complete and is co-authored by Moetasim Ashfaq, a former Stanford postdoctoral fellow now at the Oak Ridge National Laboratory. The study comes on the heels of a recent NASA report, which concluded that the previous decade, January 2000 to December 2009, was the warmest on record.

The contiguous United States had its fourth-warmest summer (June-August) on record, according to the latest NOAA State of the Climate report issued September 8. The report also showed the August average temperature was 75.0 degrees F, which is 2.2 degrees F above the long-term (1901-2000) average. Last month’s average precipitation was 2.41 inches, 0.19 inch below the 1901-2000 average.

The first eight months of 2010 tied the same period in 1998 for the warmest combined land and ocean surface temperature on record worldwide. Meanwhile, the June-August summer was the second warmest on record globally after 1998, and last month was the third warmest August on record. Separately, last month’s global average land surface temperature was the second warmest on record for August, while the global ocean surface temperature tied with 1997 as the sixth warmest for August.

In the 1990s, observations did not show the troposphere, particularly in the tropics, to be warming, even though surface temperatures were rapidly warming. This lack of tropospheric warming was used by some to question both the reality of the surface warming trend and the reliability of climate models as tools. This new paper extensively reviews the relevant scientific analyses — 195 cited papers, model results and atmospheric data sets — and finds that there is no longer evidence for a fundamental discrepancy and that the troposphere is warming.

In the first comprehensive global survey of temperature trends in major lakes, NASA researchers determined Earth’s largest lakes have warmed during the past 25 years in response to climate change.

The analysis found 2010 approximately 1.34 F warmer than the average global surface temperature from 1951 to 1980. To measure climate change, scientists look at long-term trends. The temperature trend, including data from 2010, shows the climate has warmed by approximately 0.36 F per decade since the late 1970s.

In a study published Oct. 25, 2011, in IOP Publishing’s Environmental Research Letters, scientists examined data from 111 weather stations across south-western China and have shown that temperature patterns were consistent with warming, at a statistically significant level, between 1961 and 2008.

Since 1975, five high-elevation lakes in the Adirondacks have had rapid decreases in the duration of ice cover and are now frozen for 7 to 21 fewer days on average, according to a study published April 30 in the journal Climatic Change by a team of researchers at the SUNY College of Environmental Science and Forestry (ESF).

One popular climate record that shows a slower atmospheric warming trend than other studies contains a data calibration problem, and when the problem is corrected the results fall in line with other records and climate models, according to a new University of Washington study.

According to NOAA scientists, the average temperature for the contiguous U.S. during May was 64.3°F, 3.3°F above the long-term average, making it the second warmest May on record. The month's high temperatures also contributed to the warmest spring, warmest year-to-date, and warmest 12-month period the nation has experienced since recordkeeping began in 1895.

By the end of the century, almost all of North America and most of Europe is projected to see a jump in the frequency of wildfires, primarily because of increasing temperature trends. At the same time, fire activity could actually decrease around equatorial regions, particularly among the tropical rainforests, because of increased rainfall.

A groundbreaking new study led by UCLA climate expert Alex Hall shows that climate change will cause temperatures in the Los Angeles region to rise by an average of 4 to 5 degrees Fahrenheit by the middle of this century, tripling the number of extremely hot days in the downtown area and quadrupling the number in the valleys and at high elevations.

The recent heat wave baking much of the country has prompted many people to ask: Is this due to climate change?

"This is always the million-dollar question, but unfortunately, there's no definitive way to answer it," says Steve Vavrus, a senior scientist in the Nelson Institute Center for Climatic Research at the University of Wisconsin-Madison. "We've experienced extreme heat, drought, floods, wildfires and windstorms throughout history, so in a sense this is nothing unusual. We need time to assess whether this year's set of extreme weather events falls outside of normal variations."

Climate change drove coral reefs to a total ecosystem collapse lasting thousands of years, according to a paper published this week in Science. The paper shows how natural climatic shifts stopped reef growth in the eastern Pacific for 2,500 years. The reef shutdown, which began 4,000 years ago, corresponds to a period of dramatic swings in the El Niño-Southern Oscillation (ENSO). "As humans continue to pump greenhouse gases into the atmosphere, the climate is once again on the threshold of a new regime, with dire consequences for reef ecosystems unless we get control of climate change," said coauthor Richard Aronson, a biology professor at Florida Institute of Technology.

An international team that includes scientists from Johannes Gutenberg University Mainz (JGU) has published a reconstruction of the climate in northern Europe over the last 2,000 years based on the information provided by tree-rings. Professor Dr. Jan Esper's group at the Institute of Geography at JGU used tree-ring density measurements from sub-fossil pine trees originating from Finnish Lapland to produce a reconstruction reaching back to 138 BC. In so doing, the researchers have been able for the first time to precisely demonstrate that the long-term trend over the past two millennia has been towards climatic cooling.

Researchers are working to identify exactly how a changing climate will impact specific elements of weather, such as clouds, rainfall, and lightning. A Tel Aviv University researcher has predicted that for every one degree Celsius of warming, there will be approximately a 10 percent increase in lightning activity.

Global warming also affects lakes. Based on the example of Lake Zurich, researchers from the University of Zurich demonstrate that there is insufficient water turnover in the lake during the winter and harmful Burgundy blood algae are increasingly thriving. The warmer temperatures are thus compromising the successful lake clean-ups of recent decades.

The study was led by researchers at the University of Melbourne and used a range of natural indicators including tree rings, corals and ice cores to study Australasian temperatures over the past millennium and compared them to climate model simulations.

The 20 scientists involved in the project concluded that there were fewer fires following the onset of a global cooling trend hundreds of years ago. Conversely, there were more fires after the trend reversed into a period of global warming.

If you live in the Northeast, welcome to the hottest year on record. New data released by the Northeast Regional Climate Center at Cornell University shows the Northeast's seven-month average (January through July) of 49.9 degrees was the warmest such period since 1895, the year such record keeping began. It was the second warmest such period in Pennsylvania and West Virginia, and the warmest first seven months of the year in the rest of the Northeast.

A new statistical analysis by NASA scientists has found that Earth's land areas have become much more likely to experience an extreme summer heat wave than they were in the middle of the 20th century.

According to NOAA scientists, the average temperature for the contiguous U.S. during July was 77.6°F, 3.3°F above the 20th century average, marking the hottest July and the hottest month on record for the nation. The previous warmest July for the nation was July 1936 when the average U.S. temperature was 77.4°F. The warm July temperatures contributed to a record-warm first seven months of the year and the warmest 12-month period the nation has experienced since recordkeeping began in 1895.

Research has revealed that the extremely hot, dry and windy conditions on Black Saturday in the Australian state of Victoria combined with structures in the atmosphere called 'horizontal convective rolls' -- similar to streamers of wind flowing through the air -- which likely affected fire behaviour.

The study, which is reported in the journal Science, offers new insights into a decades-long debate about how the shifts in Earth's orbit relative to the sun have taken Earth into and out of an ice-age climate.

The lack of rainfall has decimated many corn crops, which were damaged as a result of not enough rain during its crucial pollination period. So even though growers planted a record acreage of corn this year in anticipation of a strong year with record yields, the lack of enough rainfall has caused yield forecasts to continue to decline, Roberts said.

A new study led by scientists at the University of York has shown how birds, butterflies, other insects and spiders have colonised nature reserves and areas protected for wildlife, as they move north in response to climate change and other environmental changes.

Climate researchers Alexander Gershunov and Kristen Guirguis detected a trend toward more humid heatwaves that are expressed very strongly in elevated nighttime temperatures, a trend consistent with climate change projections. Moreover, relative to local warming, the mid-summer heatwaves are getting stronger in generally cooler coastal areas. This carries implications for the millions of Californians living near the ocean whose everyday lives are acclimated to moderate temperatures.

Viewed as a potential target in the global effort to reduce climate change, atmospheric black carbon particles absorb significantly less sunlight than scientists predicted, raising new questions about the impact of black carbon on atmospheric warming, an international team of researchers, including climate chemists from Boston College, report August 30 in the latest edition of the journal Science.

The Effects of Methane on Climate Change

noreply@blogger.com (Allen) — Tue, 26 Jun 2012 03:07:00 +0000

Methane is one of the more active greenhouse gases. This page gives links to pages discussing the effects of Methane on our climate.

German researchers have identified a previously unknown emitter of methane, a potent greenhouse gas. The culprit: ordinary plants.

After taking a rented camper outfitted with special equipment to measure methane on a cross-continent drive, a UC Santa Barbara scientist has found that methane emissions across large parts of the U.S. are higher than currently known, confirming what other more local studies have found. Their research is published in the journal Atmospheric Environment.

Methane is a potent greenhouse gas, and researchers don't yet fully understand the magnitude to which seeping methane in the ocean contributes additional carbon to the atmosphere. Moreover, on many continental margins, frozen methane hydrates could represent a future energy source. Along the West Coast, methane seeps are known to exist off Oregon, California (near Eureka, Monterey Bay, Point Conception and Santa Monica), in the Gulf of California and off Costa Rica.

A team of scientists from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association (AWI) and the GFZ German Research Centre for Geosciences has just completed an airborne measurement campaign that allowed for the first time to measure large-scale methane emissions from the extensive Arctic permafrost landscapes. The study area extended from Barrow, the northernmost settlement on the American mainland, across the entire North Slope of Alaska, to the Mackenzie Delta in the Northwest Territories of Canada.

Bridget Deemer, a doctoral student at Washington State University-Vancouver, measured dissolved gases in the water column of Lacamas Lake in Clark County and found methane emissions jumped 20-fold when the water level was drawn down. A fellow WSU-Vancouver student, Maria Glavin, sampled bubbles rising from the lake mud and measured a 36-fold increase in methane during a drawdown.

The Effect of Other Greenhouse Gases on Climate Change

noreply@blogger.com (Allen) — Tue, 26 Jun 2012 02:37:00 +0000

This page contains links to pages discussing the emission of greenhouse gases into the atmosphere.

"Our data clearly shows a break point in 1982, where the entire growth patterns of the trees in this forest started on a different trajectory," Nippert said. "It took 10 years for that landmark environmental legislation to reduce sulfur dioxide emissions, but it eventually did. When it did, we saw an entire ecosystem recover from years of acidic pollution."

Right now, if businesses or environmental officials need to estimate the impact of different greenhouse gas (GHG) reduction measures in one country or region of North America compared to another, they face multiple GHG reporting regimes with varying levels of detail and complexity.

Outgoing environment minister A Raja has said India was among the lowest polluters with emission levels of four per cent. Blaming the developed countries for being major contributors to global warming, he said India was mobilising the developing nations to protest against the high emissions levels of the USA-led affluent countries. [posted by the Hindustan Times (online) on May 20, 2007]

The newest analysis of trace gases trapped in Antarctic ice cores now provide a reasonable view of greenhouse gas concentrations as much as 800,000 years into the past, and are further confirming the link between greenhouse gas levels and global warming, scientists reported May 14 in the journal Nature.

The United Nations on Wednesday launched a web portal [http://www.cdmbazaar.net] to spur a market-driven trading service designed to help cut greenhouse gas emissions under the Kyoto Protocol.

These climate changes, the statement says, are “best explained by the increased atmospheric abundances of greenhouse gases and aerosols generated by human activity during the 20th century.”

The findings, just published in the online edition of the journal Science, shed further light on the fluctuations in greenhouse gases and climate in Earth’s past, and appear to confirm the validity of the types of computer models that are used to project a warmer climate in the future, researchers said.

How can we be sure that humans are responsible for these increases? Some greenhouse gases (most of the halocarbons, for example) have no natural source. For other gases, two important observations demonstrate human influence. First, the geographic differences in concentrations reveal that sources occur predominantly over land in the more heavily populated Northern Hemisphere. Second, analysis of isotopes, which can distinguish among sources of emissions, demonstrates that the majority of the increase in carbon dioxide comes from combustion of fossil fuels (coal, oil and natural gas). Methane and nitrous oxide increases derive from agricultural practices and the burning of fossil fuels.

The threat of global warming can still be greatly diminished if nations cut emissions of heat-trapping greenhouse gases by 70 percent this century, according to a new analysis. While global temperatures would rise, the most dangerous potential aspects of climate change, including massive losses of Arctic sea ice and permafrost and significant sea level rise, could be partially avoided.

Researchers from Brown University and the University of Washington have found a new way to make the link. The scientists show that comparing nitrogen isotopes in their deposited form — nitrates — can reveal the sources of atmospheric nitric oxide. In a paper published June 5 in Science, the group traces the source of nitrates to nitric oxides released through fossil fuel burning that parallels the beginning of the Industrial Revolution. The group also reveals that the greatest change in nitrogen isotope ratios occurred between 1950 and 1980, following a rapid increase in fossil fuel emissions.

Observations show that the tropics have widened by 0.7 degrees latitude per decade, with warming from greenhouse gases also contributing to the expansion in both hemispheres. To study this expansion, the researchers first compared observational data with simulated data from climate models for 1979-1999. The simulated data were generated by a collection of 20 climate models called the Coupled Model Intercomparison Project version 3 or "CMIP3."

These eruptions are known as super-eruptions because they are more than 100 times the size of ordinary volcanic eruptions like Mount St. Helens. They spew out tremendous flows of super-heated gas, ash and rock capable of blanketing entire continents and inject enough particulate into the stratosphere to throw the global climate into decade-long volcanic winters. In fact, there is evidence that one super-eruption, which took place in Indonesia 74,000 years ago, may have come remarkably close to wiping out the entire human species.

Giant volcanic eruptions in Nicaragua over the past 70,000 years could have injected enough gases into the atmosphere to temporarily thin the ozone layer, according to new research. And, if it happened today, a similar explosive eruption could do the same, releasing more than twice the amount of ozone-depleting halogen gases currently in stratosphere due to humanmade emissions.

Clouds of pollution over the Indian Ocean appear to cause as much warming as greenhouse gases released by human activity, a study has suggested.

The European Union implemented a cap and trade scheme in 2005 to help it fulfil its obligations under the first phase of the Kyoto Protocol for reducing carbon emissions. The Scandinavian nations had independently imposed a carbon tax in the 1990s as part of their effort to reduce carbon emissions. US researchers have tracked the carbon disclosures from both regions of Europe and found that neither the EU's carbon allocation scheme nor Scandinavia's carbon taxes have made any significant impact on reducing greenhouse gas emissions.

Rising sea levels cannot be stopped over the next several hundred years, even if deep emissions cuts lower global average temperatures, but they can be slowed down, climate scientists said in a study on Sunday. (posted by NewsDaily for July 1, 2012)

Researchers at the University of Wisconsin-Madison and Rutgers University have found that the climate effects of a hypothetical nuclear war between India and Pakistan would greatly reduce yields of staple crops, even in distant countries.

A U of S-led international research team has discovered that aerosols from relatively small volcanic eruptions can be boosted into the high atmosphere by weather systems such as monsoons, where they can affect global temperatures. The research appears in the July 6 issue of the journal Science.

A debate has raged in the past couple of years as to whether natural gas is better or worse overall than coal and oil from a global warming perspective. The back-and-forth findings have been due to the timelines taken into consideration, the details of natural gas extraction, and the electricity-generating efficiency of various fuels. An analysis by Cathles, which focuses exclusively on potential warming and ignores secondary considerations, such as economic, political, or other environmental concerns, finds that natural gas is better for electricity generation than coal and oil under all realistic circumstances.

As reported in a paper published in the July 27 issue of Science, a team of researchers led by James G. Anderson, the Philip S. Weld Professor of Atmospheric Chemistry, are warning that a newly-discovered connection between climate change and depletion of the ozone layer over the U.S. could allow more damaging ultraviolet (UV) radiation to reach the Earth's surface, leading to increased incidence of skin cancer.

"The reason is simple: Cars are getting cleaner," said Carsten Warneke, Ph.D., a NOAA-funded scientist with the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder.

The Effects of CO2 Emissions on Climate Change

noreply@blogger.com (Allen) — Tue, 26 Jun 2012 02:33:00 +0000

This page contains links to pages science reporting on the effects of CO2 on the climate of a planet.

"Currently, carbon dioxide levels are just above 400 parts per million (ppm), up approximately 120 ppm in the last 150 years and rising about 2 ppm each year," said Ken MacLeod, a professor of geological sciences at MU. "In our study, we found that during the Late Cretaceous Period, when carbon dioxide levels were around 1,000 ppm, there were no continental ice sheets on earth. So, if carbon dioxide levels continue to rise, the Earth will be ice-free once the climate comes into balance with the higher levels."

Under elevated carbon dioxide levels, wetland plants can absorb up to 32 percent more carbon than they do at current levels, according to a 19-year study published in Global Change Biology from the Smithsonian Environmental Research Center in Edgewater, Md. With atmospheric CO₂ passing the 400 parts-per-million milestone this year, the findings offer hope that wetlands could help soften the blow of climate change.

An instrument near the summit of Mauna Loa in Hawaii recorded a long-awaited climate milestone today: the amount of carbon dioxide in the atmosphere there has exceeded 400 parts per million (ppm) for the first time in 55 years of measurement—and probably more than 3 million years of Earth history.

More carbon dioxide is released from residential lawns than corn fields according to a new study. And much of the difference can likely be attributed to soil temperature. The data, from researchers at Elizabethtown College, suggest that urban heat islands may be working at smaller scales than previously thought.

Global carbon dioxide (CO₂) emissions are set to rise again in 2012, reaching a record high of 35.6 billion tonnes -- according to new figures from the Global Carbon Project, co-led by researchers from the Tyndall Centre for Climate Change Research at the University of East Anglia (UEA).

Feeding the world releases up to 17,000 megatonnes of carbon dioxide into the atmosphere annually, according to a new analysis released October 30 by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS). But while the emissions "footprint" of food production needs to be reduced, a companion policy brief by CCAFS lays out how climate change will require a complete recalibration of where specific crops are grown and livestock are raised.

Researchers from the Massachusetts Institute for Technology have shown that the material strength and fracture toughness of ice are decreased significantly under increasing concentrations of CO₂ molecules, making ice caps and glaciers more vulnerable to cracking and splitting into pieces, as was seen recently when a huge crack in the Pine Island Glacier in Antarctica spawned a glacier the size of Berlin.

The study also shows that the observed warming in the North Atlantic during the 20th century cannot be explained by the solar and volcanic activity alone. In the model, the increased emissions of CO2 and other well-mixed greenhouse gases to the atmosphere since the onset of the industrial revolution have to be included in order to simulate the observed temperature evolution.

A new peer-reviewed scientific study counters a major premise of global warming theory, concluding carbon dioxide did not end the last ice age.

Using computer modeling to integrate forest canopy measurements and remote satellite data, researchers found that autumn warming greatly increases soil decomposition and significantly reduces carbon dioxide uptake.

India will become the third-biggest emitter of carbon dioxide by 2015 and rapid economic growth of the country and its neighbour China will have devastating consequences for the world's energy supply unless the two Asian giants make efforts to curb demand and greenhouse gas emissions, the International Energy Agency warned on Wednesday.

To discover how the situation has changed since the last ice age, researchers studied 20,000-year-old mud samples from the sub-Arctic Pacific Ocean lying approximately three feet below the present sea bed. They found the water in the ocean’s depths exchanged less CO2 with the atmosphere than it does at present, while capturing more atmospheric CO2 than the water does today, suggesting as oceans become warmer as a result of climate change they release more carbon dioxide into the atmosphere. [posted by NewsDaily on January 24, 2008]

Global temperatures could be less sensitive to changing atmospheric carbon dioxide (CO2) levels than previously thought, a study suggests.http://www.sciencedaily.com/releases/2012/12/121202164059.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29

“The system is finely in tune,” says Caldeira. “That one or two percent imbalance works out to an average imbalance in natural carbon dioxide emissions that is thousands of times smaller than our current emissions from industry and the destruction of forests.”

Before humans began burning fossil fuels, there was an eons-long balance between carbon dioxide emissions and Earth’s ability to absorb them, but now the planet can’t keep up, scientists said on Sunday. [posted by NewsDaily on April 27, 2008]

Climatologists from Bern University said their study also showed that concentrations of greenhouse gases are increasing at a faster rate, Swissinfo.com reported. For example, the concentration of carbon dioxide increased by 31 parts per million during one 1,600-year interval in the pre-industrial period — its fastest growth before the industrial age — and went up by the same amount in the past 20 years. [posted by NewsDaily on February 1, 2008]

Australian and international researchers have found that weakening of the land and ocean sinks is causing carbon dioxide to accumulate in the atmosphere faster than expected.

The basic proposition behind the science of climate change is so firmly rooted in the laws of physics that no reasonable person can dispute it. All other things being equal, adding carbon dioxide (CO₂) to the atmosphere—by, for example, burning millions of tons of oil, coal and natural gas—will make it warm up. That, as the Nobel Prize–winning chemist Svante Arrhenius first explained in 1896, is because CO₂ is relatively transparent to visible light from the sun, which heats the planet during the day. But it is relatively opaque to infrared, which the earth tries to reradiate back into space at night. If the planet were a featureless, monochromatic billiard ball without mountains, oceans, vegetation and polar ice caps, a steadily rising concentration of CO₂ would mean a steadily warming earth. Period.

Researchers measured an additional 16.2 billion tons of carbon dioxide (CO₂) — a byproduct of fossil fuel burning — and 12.2 million tons of methane in the atmosphere at the end of December 2008. This increase is despite the global economic downturn, with its decrease in a wide range of activities that depend on fossil fuel use.

Most of the carbon dioxide emitted by human activity does not remain in the atmosphere, but is instead absorbed by the oceans and terrestrial ecosystems. In fact, only about 45 percent of emitted carbon dioxide stays in the atmosphere.

According to current best estimates of climate sensitivity, the amount of CO2 and other heat-trapping gases added to Earth’s atmosphere since humanity began burning fossil fuels on a significant scale during the industrial period would be expected to result in a mean global temperature rise of 3.8°F — well more than the 1.4°F increase that has been observed for this time span. Schwartz’s analysis attributes the reasons for this discrepancy to a possible mix of two major factors: 1) Earth’s climate may be less sensitive to rising greenhouse gases than currently assumed and/or 2) reflection of sunlight by haze particles in the atmosphere may be offsetting some of the expected warming.

A new estimate of the feedback between temperature and atmospheric carbon dioxide (CO2) concentration has been derived from a comprehensive comparison of temperature and CO2 records spanning the past millennium.

In a paper published November 21 in Nature Geoscience, the authors found that despite the major financial crisis that hit the world last year, global CO2 emissions from the burning of fossil fuel in 2009 were only 1.3 per cent below the record 2008 figures. This is less than half the drop predicted a year ago.

Recently, destructive peat fires plagued the Moscow region. In the late 1990s, severe Indonesian fires in drained peatlands released carbon equivalent to 40 per cent of annual global fossil fuel emissions.

A drop in carbon dioxide appears to be the driving force that led to the Antarctic ice sheet’s formation, according to a recent study led by scientists at Yale and Purdue universities of molecules from ancient algae found in deep-sea core samples.

The new study created a computer simulation of CO₂ emissions in the Salt Lake Valley using three sources of information:

CO₂ measurements from three sites -- the University of Utah, downtown Salt Lake City and Murray, Utah, about halfway south down the valley's length.

Data from weather stations in the valley, crunched through weather forecasting software used to predict wind and air circulation.

Satellite data showing what parts of the valley are covered by homes, other buildings, trees, agriculture and so on.

"We found that decades-old carbon in surface soils is released to the atmosphere faster when temperatures become warmer," said lead author Francesca Hopkins, a doctoral researcher in UCI's Earth system science department. "This suggests that soils could accelerate global warming through a vicious cycle in which human-made warming releases carbon from soils to the atmosphere, which, in turn, would warm the planet more."

Based on Hansen's temperature analysis work at the Goddard Institute for Space Studies, Earth's average global surface temperature has already risen .8 degrees Celsius since 1880, and is now warming at a rate of more than .1 degree Celsius every decade. This warming is largely driven by increased greenhouse gases in the atmosphere, particularly carbon dioxide, emitted by the burning of fossil fuels at power plants, in cars and in industry. At the current rate of fossil fuel burning, the concentration of carbon dioxide in the atmosphere will have doubled from pre-industrial times by the middle of this century. A doubling of carbon dioxide would cause an eventual warming of several degrees, Hansen said.

In spite of the rise in atmospheric CO₂ concentration of about 70 parts per million by volume and in global temperatures of about 0.50°C over the last 6 decades, the All India Rainfall index does not yet show the expected increase in rainfall. The reviewers Andrew Turner from the Department of Meteorology at the University of Reading and H. Annamalai from the International Pacific Research Center at the University of Hawaii at Manoa give several reasons for why the region's observed rainfall has not yet increased, among them are inconsistent rainfall observations, decadal variability of the monsoon, the effects of aerosols resulting from industrialization, and land-use changes.

Research scientist Sassan Saatchi of NASA's Jet Propulsion Laboratory, Pasadena, Calif., participated in the study, published June 21 in the journal Science. The team, led by researchers from Winrock International, an environmental nonprofit organization in Little Rock, Ark., also included scientists from Applied GeoSolutions, Durham, N.H.; and the University of Maryland, College Park. They combined satellite data on gross forest loss and forest carbon stocks to track emissions from deforestation in the world's tropical forests. The resulting gross emissions estimate of 0.81 billion metric tons of carbon emitted per year is approximately one third of previously published estimates, and represents just 10 percent of the total global human-produced carbon emissions over the time period analyzed (2000 to 2005).

In what might be the first study to report continuous measurements of net CO₂ exchange of urban vegetation and soils over a full year or more, scientists from UC Santa Barbara and the University of Minnesota conclude that not only is vegetation important in the uptake of the greenhouse gas, but also that different types of vegetation play different roles.

The new Harvard-Nanjing study goes deeper, however, constructing a "bottom-up" emission inventory that is specific to China's energy and technology mix. It combines the results of Chinese field studies of CO₂ emissions from diverse combustion processes with a plant-by-plant data set for power generation, independent research on transportation and rural biomass use, and provincial-level energy statistics for the remaining sectors.

The new evidence supports an emerging view that although forests remove a substantial amount of carbon dioxide from the atmosphere, much of the carbon is being stored in living woody biomass rather than as dead organic matter in soils.

Global emissions of carbon dioxide (CO₂) -- the main cause of global warming -- increased by 3% last year, reaching an all-time high of 34 billion tonnes in 2011. In China, the world's most populous country, average emissions of CO₂ increased by 9% to 7.2 tonnes per capita. China is now within the range of 6 to 19 tonnes per capita emissions of the major industrialised countries. In the European Union, CO₂ emissions dropped by 3% to 7.5 tonnes per capita. The United States remains one of the largest emitters of CO₂, with 17.3 tones per capita, despite a decline due to the recession in 2008-2009, high oil prices and an increased share of natural gas.

"Our analyses of ice cores from the ice sheet in Antarctica shows that the concentration of CO₂ in the atmosphere follows the rise in Antarctic temperatures very closely and is staggered by a few hundred years at most," explains Sune Olander Rasmussen, Associate Professor and centre coordinator at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.

Using 15 of the most robust proxy records of marine and terrestrial climate, Das Sharma et al. employ new statistical and mathematical techniques to quantify the interactions among climatic parameters and to investigate which of these parameters could be the primary drivers of climate change during MIS 11. The authors find that atmospheric CO₂ concentration was indeed the primary driver of both terrestrial and marine climate: Sea surface temperature and the isotopic makeup of carbon in terrestrial and marine reservoirs responded "instantaneously" (i.e., within 1,000 years) to changes in atmospheric CO₂ content.

Earth's oceans, forests and other ecosystems continue to soak up about half the carbon dioxide emitted into the atmosphere by human activities, even as those emissions have increased, according to a study by University of Colorado and NOAA scientists published August 1 in the journal Nature.

The results were surprising. Substantially more carbon compounds where discharged by the river than the annual procedure of pre-harvest burning of sugar cane plantations could produce. "When we plotted the results from the samples against time and compared this pattern with the amount of precipitation and the occurrence of fires, the relation became obvious. The charred carbon must have originated from the slash and burn period from much earlier times."

Articles Concerning Emissions

noreply@blogger.com (Allen) — Tue, 26 Jun 2012 02:29:00 +0000

Scientists are concerned about the effect of greenhouse gases on a planet, because those gases reduce the heat lost by the planet and thus increase the temperature of the planet.

This page contains links to articles involving emissions of greenhouse gases into the air.

Ice Melting in the Arctic

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 21:46:00 +0000

This page has links to science articles discussing the melting of ice in the Arctic and to effects from that melting.

The remaining Arctic sea ice cover is much thinner on average than it was years ago. Satellite imagery, submarine sonar measurements, and data collected from NASA's Operation IceBridge, an airborne survey of polar ice, indicate that the Arctic sea ice thickness is as much as 50 percent thinner than it was in previous decades, going from an average thickness of 12.5 feet (3.8 meters) in 1980 to 6.2 feet (1.9 meters) in recent years. The thinning is due to the loss of older, thicker ice, which is being replaced by thinner seasonal ice.

"Rapid Arctic sea ice loss is probably the most visible indicator of global climate change; it leads to shifts in ecosystems and economic access, and potentially impacts weather throughout the northern hemisphere," said Overland. "Increased physical understanding of rapid Arctic climate shifts and improved models are needed that give a more detailed picture and timing of what to expect so we can better prepare and adapt to such changes. Early loss of Arctic sea ice gives immediacy to the issue of climate change."

In a paper published March 31 in Nature Climate Change, scientists reveal new models projecting that wooded areas in the Arctic could increase by as much as 50 percent over the coming decades. The researchers also show that this dramatic greening will accelerate climate warming at a rate greater than previously expected.

The new maximum -- 5.82 million square miles (15.09 million square kilometers) -- is in line with a continuing trend in declining winter Arctic sea ice extent: nine of the ten smallest recorded maximums have occurred during the last decade. The 2013 winter extent is 144,402 square miles (374,000 square kilometers) below the average annual maximum extent for the last three decades.

Ongoing glacier loss in the Canadian high Arctic is accelerating and probably irreversible, new model projections by Lenaerts et al. suggest. The Canadian high Arctic is home to the largest clustering of glacier ice outside of Greenland and Antarctica -- 146,000 square kilometers (about 60,000 square miles) of glacier ice spread across 36,000 islands.

The widespread reduction in Arctic sea ice is causing significant changes to the balance of greenhouse gases in the atmosphere. This is shown in a new study conducted by researchers from Lund University in Sweden, among others.

Ancient carbon trapped in Arctic permafrost is extremely sensitive to sunlight and, if exposed to the surface when long-frozen soils melt and collapse, can release climate-warming carbon dioxide gas into the atmosphere much faster than previously thought.

It came out of Siberia, swirling winds over an area that covered almost the entire Arctic basin in the normally calm late summer. It came to be known as "The Great Arctic Cyclone of August 2012," and for some observers it suggested that the historic sea ice minimum may have been caused by a freak summer storm, rather than warming temperatures.

Melting Arctic sea ice is no longer just evidence of a rapidly warming planet -- it's also part of the problem.

The Arctic sea ice has not only declined over the past decade but has also become distinctly thinner and younger. Researchers are now observing mainly thin, first-year ice floes which are extensively covered with melt ponds in the summer months where once metre-thick, multi-year ice used to float. Sea ice physicists at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), have now measured the light transmission through the Arctic sea ice for the first time on a large scale, enabling them to quantify consequences of this change.

As much as 44 billion tons of nitrogen and 850 billion tons of carbon stored in arctic permafrost, or frozen ground, could be released into the environment as the region begins to thaw over the next century as a result of a warmer planet, according to a new study led by the U.S. Geological Survey. This nitrogen and carbon are likely to impact ecosystems, the atmosphere, and water resources including rivers and lakes. For context, this is roughly the amount of carbon stored in the atmosphere today.

Earth's poles have very different geographies. The Arctic Ocean is surrounded by North America, Greenland and Eurasia. These large landmasses trap most of the sea ice, which builds up and retreats with each yearly freeze-and-melt cycle. But a large fraction of the older, thicker Arctic sea ice has disappeared over the last three decades. The shrinking summer ice cover has exposed dark ocean water that absorbs sunlight and warms up, leading to more ice loss.
On the opposite side of the planet, Antarctica is a continent circled by open waters that let sea ice expand during the winter but also offer less shelter during the melt season. Most of the Southern Ocean's frozen cover grows and retreats every year, leading to little perennial sea ice in Antarctica.

The near-record ice melt occurred without the unusual weather conditions that contributed to the extreme melt of 2007. In 2007, winds and weather patterns helped melt large expanses of ice. "Atmospheric and oceanic conditions were not as conducive to ice loss this year, but the melt still reached a new record low," said NSIDC scientist Walt Meier. "This probably reflects loss of multi-year ice in the Arctic, as well as other factors that are making the ice more vulnerable." Multi-year ice is ice that has survived more than one melt season and is thicker than first-year ice.

With the melting ice in the Arctic, U.S. Coast Guard crews based in Alaska have taken on a new challenge: carefully deploying scientific equipment through cracks in the ice from an airplane hundreds of feet in the air.

Yackel and the university-based Cryosphere Climate Research Group use satellite technology to research the physical properties of Arctic ice. As recently as the 1980s, most of the ice in the Arctic Ocean was "multi-year ice," -- thick ice that would remain throughout the summer. At that time, the split between multi-year ice and seasonal ice -- ice that would melt away in the summer -- was about 80 per cent multi-year and 20 per cent seasonal.
"In the last 20 years we've almost gotten to the point where we've reversed that ratio," Yackel says, predicting the ice extent that covers the Arctic Ocean "is likely to be gone in the summers within the next 20 to 25 years, if not sooner."

The frozen cap of the Arctic Ocean appears to have reached its annual summertime minimum extent and broken a new record low on Sept. 16, the National Snow and Ice Data Center (NSIDC) has reported. Analysis of satellite data by NASA and the NASA-supported NSIDC at the University of Colorado in Boulder showed that the sea ice extent shrunk to 1.32 million square miles (3.41 million square kilometers).

"The snowfall rate increases slightly in the middle of winter by the end of the century," Hezel said. However, at the same time sea ice is expected to start forming later in the year than it does now. The slightly heavier snowfall in the winter won't compensate for the fact that in the fall -- which is also when it snows the heaviest -- snow will drop into the ocean instead of piling up on the ice.

According to the new research, glaciers on Canada's Baffin Island expanded rapidly during a brief cold snap about 8,200 years ago. The discovery adds to a growing body of evidence showing that ice sheets reacted rapidly in the past to cooling or warming, raising concerns that they could do so again as Earth heats up.

Global warming in the Arctic is mysteriously occurring more quickly 1.2 miles (2 kilometers) above the surface than at ground level, a new study says.

To discover how the situation has changed since the last ice age, researchers studied 20,000-year-old mud samples from the sub-Arctic Pacific Ocean lying approximately three feet below the present sea bed. They found the water in the ocean’s depths exchanged less CO2 with the atmosphere than it does at present, while capturing more atmospheric CO2 than the water does today, suggesting as oceans become warmer as a result of climate change they release more carbon dioxide into the atmosphere. [posted by NewsDaily on January 24, 2008]

Arctic ice has reformed rapidly this winter after a record summer low, but it still covers less of the Arctic Ocean than it did in previous decades, NASA scientists announced today in an update of the states of Arctic and Antarctic sea ice.

Today’s Arctic explorers are well-acquainted with the ugly haze that hangs over the North Pole, created by air pollution that drifts up from cities in lower latitudes. But a new study suggests this veil of pollution has been present since the late 1800s.

The thickest, oldest and toughest sea ice around the North Pole is melting, a bad sign for the future of the Arctic ice cap, NASA satellite data showed on Tuesday. [posted by NewsDaily on March 18, 2008]

NOAA scientists are now flying through springtime Arctic pollution to find out why the region is warming — and summertime sea ice is melting — faster than predicted. Some 35 NOAA researchers are gathering with government and university colleagues in Fairbanks, Alaska, to conduct the study through April 23.

A team of scientists including polar expert Dr. Derek Mueller from Trent University and Canadian Rangers have discovered that the largest ice shelf in the Northern Hemisphere has fractured into three main pieces.

The ice cover in the Arctic Ocean at the end of summer 2008 will lie, with almost 100 per cent probability, below that of the year 2005 — the year with the second lowest sea ice extent ever measured. Chances of an equally low value as in the extreme conditions of the year 2007 lie around eight per cent. Climate scientists from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association come to this conclusion in a recent model calculation.

Most glaciers in every mountain range and island group in Alaska are experiencing significant retreat, thinning or stagnation, especially glaciers at lower elevations, according to a new book published by the U.S. Geological Survey. In places, these changes began as early as the middle of the 18th century.

Until recent years, measurements have shown most Arctic ice has survived at least one summer and often several, said Meier. But the balance has now flipped, and seasonal ice -- which melts and re-freezes every year -- now comprises about 70 percent of Arctic sea ice in winter, up from 40 to 50 percent in the 1980s and 1990s, he said. Thicker ice that has survived two or more years now comprises just 10 percent of ice cover, down from 30 to 40 percent in years past.

The Arctic ice cap grows each winter as the sun sets for several months and intense cold ensues. In the summer, wind and ocean currents cause some of the ice naturally to flow out of the Arctic, while much of it melts in place. But not all of the Arctic ice melts each summer; the thicker, older ice is more likely to survive. Seasonal sea ice usually reaches about 2 meters (6 feet) in thickness, while multi-year ice averages 3 meters (9 feet).

New evidence for ice-free summers with intermittent winter sea ice in the Arctic Ocean during the Late Cretaceous – a period of greenhouse conditions – gives a glimpse of how the Arctic is likely to respond to future global warming.

The findings, detailed in the Sept. 4 issue of the journal Science, also suggest that if it weren’t for these manmade pollutants, temperatures around the North Pole would actually be cooling as a result of natural climate patterns.

Based on its long-term orbit, Earth should be heading into an ice age. But instead of continuing to cool—as it had been for at least the past 2,000 years—the Arctic has started to warm. And the reason is humans’ impact on the composition of the atmosphere, new research suggests.

Sea ice is like rainforest in the tropics. There are species that can’t live without it,” says ecologist Eric Post of The Pennsylvania State University, lead author of a paper in the September 11 Science that lays out a broad review of climate change’s impact on the Arctic. “It’s melting earlier, freezing up later, the contiguous extent is diminishing, and it’s happening faster than anyone expected it to happen 10 years ago.”

The possibility that climate change might simply be a natural variation like others that have occurred throughout geologic time is dimming, according to evidence in a Proceedings of the National Academy of Sciences paper published October 19.

The research team, led by Étienne Berthier of the Laboratory for Space Studies in Geophysics and Oceanography at the Université de Toulouse in France, says that glacier melt in Alaska between 1962 and 2006 contributed about one-third less to sea-level rise than previously estimated.

“The sea ice acts like a shiny lid on the Arctic Ocean. When it is heated, it reflects most of the incoming sunlight back into space. When the sea ice melts, more heat is absorbed by the water. The warmer water then heats the atmosphere above it.”

Scientists from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association (AWI) in Bremerhaven and from KlimaCampus of the University of Hamburg have now published data in this context in the annual issue of Sea Ice Outlook. The online publication compares the forecasts on ice cover for September 2010 prepared by around a dozen international research institutes in a scientific “competition.” The ice reaches its minimum area at this time every year.

While this year’s September minimum extent was greater than 2007 and 2008, the two record-setting and near-record-setting low years, it is still significantly below the long-term average and well outside the range of natural climate variability, according to CU-Boulder’s NSIDC scientists. Most researchers believe the shrinking Arctic sea ice is tied to warming temperatures caused by an increase in human-produced greenhouse gases being pumped into Earth’s atmosphere.

“Other sea ice data are available from other data providers, using different satellite sensors and sea ice algorithms. For example, data from the University of Bremen indicate that sea ice extent from their algorithm fell below the 2007 minimum. They employ an algorithm that uses high resolution information from the JAXA AMSR-E sensor on the NASA Aqua satellite. This resolution allows small ice and open water features to be detected that are not observed by other products. This year the ice cover is more dispersed than 2007 with many of these small open water areas within the ice pack. While the University of Bremen and other data may show slightly different numbers, all of the data agree that Arctic sea ice is continuing its long-term decline.”

A new study led by the Georgia Institute of Technology provides further evidence of a relationship between melting ice in the Arctic regions and widespread cold outbreaks in the Northern Hemisphere. The study’s findings could be used to improve seasonal forecasting of snow and temperature anomalies across northern continents.

Scientists from the Woods Hole Oceanographic Institution (WHOI) have conducted a new study to measure levels of carbon at various depths in the Arctic Ocean. The study, recently published in the journal Biogeosciences, provides data that will help researchers better understand the Arctic Ocean's carbon cycle -- the pathway through which carbon enters and is used by the marine ecosystem. It will also offer an important point of reference for determining how those levels of carbon change over time, and how the ecosystem responds to rising global temperatures.

"At this point we can only speculate as to how the mercury enters the river systems, but it appears that climate change may play a large role," says Jacob. "As global temperatures rise, we begin to see areas of permafrost thawing and releasing mercury that was locked in the soil; we also see the hydrological cycle changing, increasing the amount of runoff from precipitation that enters the rivers."

That's because melting Arctic sea ice can trigger a domino effect leading to increased odds of severe winter weather outbreaks in the Northern Hemisphere's middle latitudes -- think the "Snowmageddon" storm that hamstrung Washington, D.C., during February 2010.

However, in situ observations made in September 2009 by Barber et al. show that much of the ice was in fact “rotten” ice — ice that is thinner, heavily decayed, and structurally weak due to a uniform temperature throughout.

They show that the extreme warm periods in the Arctic correspond closely with times when parts of Antarctica were also ice-free and warm, suggesting a strong connection between Northern and Southern Hemisphere climate.

The combination of melting sea ice and global atmospheric warming are contributing to the high rate of warming in the Arctic, where temperatures are increasing up to four times faster than the global average, a new University of Melbourne study has shown.

Researchers are working hard to improve their ability to more accurately predict how much Arctic sea ice will remain at the end of summer. It's an important exercise because knowing why sea ice declines could help scientists better understand climate change and how sea ice is evolving.

"What we see in Nares Strait is some of the hardest and thickest ice leaving the Arctic where some of it is replaced by much thinner ice that has not been hardened by many sequential freeze/melt cycles," Muenchow says. "The harder thicker ice is called 'multi-year' ice, distinct from first-year ice, and the slow disappearance of this multi-year ice from northern Canada and Greenland is one major factor causing the ice extent to become steadily smaller over the last 40 years or so. Most climate models predicted this scenario, but we are 30 to 40 years ahead of the predicted schedule with regard to the ice cover in the Arctic."

The extent of the sea ice covering the Arctic Ocean has shrunk. According to scientists from NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) in Boulder, Colo., the amount is the smallest size ever observed in the three decades since consistent satellite observations of the polar cap began.

The Northeast Passage and Climate Change

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 21:27:00 +0000

This page contains links to articles discussing the effect of climate change on the Northeast Passage.

"While existing geologic records from the Arctic contain important hints about this time period, what we are presenting is the most continuous archive of information about past climate change from the entire Arctic borderlands. As if reading a detective novel, we can go back in time and reconstruct how the Arctic evolved with only a few pages missing here and there," says Brigham-Grette.

Arctic sea ice melting, which scientists have linked to global warming, maybe a boon for the shipping industry. As the sea ice continues to melt a shipping passage to Russia’s north is becoming more navigable, and now two German ships are close to completing the first trip from Asia to Europe via the Arctic shortcut. However, walruses that live in the Arctic could care less, since their sea ice habitat is rapidly disappearing.

The Northeast Passage, the sea route along the North coast of Russia, is expected to be free of ice early again this summer. The forecast was made by sea ice physicists of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association based on a series of measurement flights over the Laptev Sea, a marginal sea of the Arctic Ocean. Among experts the shelf sea is known as an "ice factory" of Arctic sea ice. At the end of last winter the researchers discovered large areas of thin ice not being thick enough to withstand the summer melt.

The National Snow and Ice Data Center reports that Arctic ice shrank by 131,000 square miles between August 17 and 21, leaving ice coverage that is well below the 2005 record low of 2.05 million square miles. This has made the Northwest Passage easier to access than was thought possible even five years ago. “We used to say that maybe by the middle of the century the Arctic would be seasonably navigable,” says Sheldon Drobot, an Arctic researcher with the Colorado Center for Astrodynamics Research. “Climate change is moving faster than we thought in the Arctic. At the current rate, we could see a seasonal shipping route in the next decade or two.”

Articles Concerning Ice Melting In the Arctic

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 21:13:00 +0000

This page has links to articles about the changing climate in the Arctic.

Ice-Melt

Northeast Passage

Deep-Water Temperatures in the Antarctica

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 20:15:00 +0000

This page gives links to articles describing the temperatures deep within the Antarctic Ocean.

The Antarctic deep sea is getting colder, which might stimulate the circulation of the oceanic water masses. This is the first result of the Polarstern expedition of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association that has just ended in Punta Arenas/Chile. At the same time satellite images from the Antarctic summer have shown the largest sea-ice extent on record. In the coming years autonomous measuring buoys will be used to find out whether the cold Antarctic summer induces a new trend or was only a “slip“.

Comparing detailed measurements taken during the Australian Antarctic program's 2012 Southern Ocean marine science voyage to historical data dating back to 1970, scientists estimate there has been as much as a 60 per cent reduction in the volume of Antarctic Bottom Water, the cold dense water that drives global ocean currents.

Ice-Melt in the Antarctica

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 20:13:00 +0000

This page gives links to articles about the changing of ice in the Antarctica.

On the other hand a subglacial eruption and the accompanying heat flow will melt a lot of ice. "The volcano will create millions of gallons of water beneath the ice -- many lakes full," says Wiens. This water will rush beneath the ice towards the sea and feed into the hydrological catchment of the MacAyeal Ice Stream, one of several major ice streams draining ice from Marie Byrd Land into the Ross Ice Shelf. By lubricating the bedrock, it will speed the flow of the overlying ice, perhaps increasing the rate of ice-mass loss in West Antarctica.

New research has revealed that more ice leaves Antarctica by melting from the underside of submerged ice shelves than was previously thought, accounting for as much as 90 per cent of ice loss in some areas.

Warm ocean water, not warm air, is melting the Pine Island Glacier's floating ice shelf in Antarctica and may be the culprit for increased melting of other ice shelves, according to an international team of researchers.

Previous work by Steig has shown that rapid thinning of Antarctic glaciers was accompanied by rapid warming and changes in atmospheric circulation near the coast. His research with Qinghua Ding, a UW research associate, showed that the majority of Antarctic warming came during the 1990s in response to El Niño conditions in the tropical Pacific Ocean.

A new 1,000-year Antarctic Peninsula climate reconstruction shows that summer ice melting has intensified almost ten-fold, and mostly since the mid-20th century. Summer ice melt affects the stability of Antarctic ice shelves and glaciers.

In two recent papers in the journals Nature Climate Change and the Proceedings of the National Academy of Sciences (PNAS), the researchers present a probabilistic assessment of the Antarctic contribution to 21st-century sea-level change. Their methodology folds observed changes and models of different complexity into unified projections that can be updated with new information. This approach provides a consistent means to integrate the potential contribution of both continental ice sheets -- Greenland and Antarctica -- into sea-level rise projections.

The Antarctic Peninsula -- a mountainous region extending northwards towards South America -- is warming much faster than the rest of Antarctica. Temperatures have risen by up to 3 oC since the 1950s -- three times more than the global average. This is a result of a strengthening of local westerly winds, causing warmer air from the sea to be pushed up and over the peninsula. In contrast to much of the rest of Antarctica, summer temperatures are high enough for snow to melt.

Future sea level rise due to the melting of the Greenland and Antarctic ice sheets could be substantially larger than estimated in Climate Change 2007, the Fourth Assessment Report of the IPCC, according to new research from the University of Bristol.

The temperature record from Byrd Station, a scientific outpost in the center of the West Antarctic Ice Sheet (WAIS), demonstrates a marked increase of 4.3 degrees Fahrenheit (2.4 degrees Celsius) in average annual temperature since 1958 -- that is, three times faster than the average temperature rise around the globe.

Researchers now believe that the catastrophic collapses of Larsen A and B were caused, at least in part, by rising temperatures in the region, where warming is increasing at six times the global average. The Antarctic Peninsula warmed 4.5 degrees Fahrenheit since the middle of the last century.

Earth's poles have very different geographies. The Arctic Ocean is surrounded by North America, Greenland and Eurasia. These large landmasses trap most of the sea ice, which builds up and retreats with each yearly freeze-and-melt cycle. But a large fraction of the older, thicker Arctic sea ice has disappeared over the last three decades. The shrinking summer ice cover has exposed dark ocean water that absorbs sunlight and warms up, leading to more ice loss.
On the opposite side of the planet, Antarctica is a continent circled by open waters that let sea ice expand during the winter but also offer less shelter during the melt season. Most of the Southern Ocean's frozen cover grows and retreats every year, leading to little perennial sea ice in Antarctica.

Warm temperatures melted an area of western Antarctica that adds up to the size of California in January 2005, scientists report.

Eric Rignot -- a senior scientist with NASA's Jet Propulsion Laboratory and lead author of the paper published online in the journal Nature Geoscience -- said Antarctica is losing ice annually, and losing it at an accelerating rate, even though land temperatures are holding steady except on the peninsula, which is warming at a rapid rate.

Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by NASA and university scientists.

Nothing, that is, until early in the Antarctic summer of 2001–2002. In November 2001 Scambos got a message he remembers vividly from Pedro Skvarca, a glaciologist based at the Argentine Antarctic Institute in Buenos Aires who was trying to conduct fieldwork on Larsen B. Water was everywhere. Deep cracks were forming. Skvarca was finding it impossible to work, impossible to move. Then, in late February 2002, the ponds began disappearing, draining—the water was indeed chiseling its way through the ice shelf. By mid-March remarkable satellite images showed that some 1,300 square miles of Larsen B, a slab bigger than the state of Rhode Island, had fragmented. Nothing remained of it except an armada of ice chunks, ranging from the size of Manhattan to the size of a microwave oven. Our emergency landing site, stable for thousands of years, was gone. On March 20 Scambos’s striking satellite images of the collapsing ice shelf appeared above the fold on the front page of the New York Times.

British Antarctic Survey has captured dramatic satellite images of an Antarctic ice shelf that looks set to be the latest to break out from the Antarctic Peninsula. A large part of the Wilkins Ice Shelf on the Antarctic Peninsula is now supported only by a thin strip of ice hanging between two islands. It is another identifiable impact of climate change on the Antarctic environment.

Antarctica hasn’t warmed as much over the last century as climate models had originally predicted, a new study finds.

The Wilkins Ice Shelf is experiencing further disintegration that is threatening the collapse of the ice bridge connecting the shelf to Charcot Island. Since the connection to the island in the image centre helps to stabilise the ice shelf, it is likely the break-up of the bridge will put the remainder of the ice shelf at risk.

The melting of glaciers is well documented, but when looking at the rate at which they have been retreating, a team of international researchers steps back and says not so fast.

The change in the ice mass covering Antarctica is a critical factor in global climate events. Scientists at the GFZ German Research Centre for Geosciences have now found that the year by year mass variations in the western Antarctic are mainly attributable to fluctuations in precipitation, which are controlled significantly by the climate phenomenon El Niño. They examined the GFZ data of the German-American satellite mission GRACE (Gravity Recovery and Climate Experiment). The investigation showed significant regional differences in the western coastal area of the South Pole area.

A drop in carbon dioxide appears to be the driving force that led to the Antarctic ice sheet’s formation, according to a recent study led by scientists at Yale and Purdue universities of molecules from ancient algae found in deep-sea core samples.

A team of scientists have drilled holes through an Antarctic ice shelf, the Fimbul Ice Shelf, to gather the first direct measurements regarding melting of the shelf's underside. A group of elephant seals, outfitted with sensors that measure salinity, temperature, and depth sensors added fundamental information to the scientists' data set, which led the researchers to conclude that parts of eastern Antarctica are melting at significantly lower rates than current models predict.

A drop in carbon dioxide appears to be the driving force that led to the Antarctic ice sheet’s formation, according to a recent study led by scientists at Yale and Purdue universities of molecules from ancient algae found in deep-sea core samples.

While studies of the Greenland and West Antarctic ice sheets show they are both at risk from global warming, the East Antarctic ice sheet will “need quite a bit of warming” to be affected, Andrew Mackintosh, a senior lecturer at Victoria University, said Wednesday.

Volcanic heat could still be melting ice to water and contributing to thinning and speeding up of the Pine Island glacier, which passes nearby, but Vaughan said he doubted that it could be affecting other glaciers in western Antarctica, which have also thinned in recent years. Most glaciologists, including Vaughan, say that warmer ocean water is the primary cause of thinning.

A review by U.S. scientists of satellite and weather records for Antarctica, which contains 90 percent of the world's ice and would raise world sea levels if it thaws, showed that freezing temperatures had risen by about 0.5 Celsius (0.8 Fahrenheit) since the 1950s. [posted by NewsDaily on January 21, 2009]

Scientists have discovered a one mile deep rift valley hidden beneath the ice in West Antarctica, which they believe is contributing to ice loss from this part of the continent.

Articles Concerning the Antarctica

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 20:09:00 +0000

This page gives links to articles about climate change in the Antarctica.

Ice-Melt

Deep Water

Other Factors

The Influence of Oceans on Climate Change

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 16:26:00 +0000

This page gives links to scientific articles about both the influence of oceans on climate change and the influence of climate change on oceans.

We also find that the detection threshold of mass loss acceleration depends on record length: to detect an acceleration at an accuracy within ±10 Gt yr⁻², a period of 10 years or more of observations is required for Antarctica and about 20 years for Greenland. Therefore, climate variability adds uncertainty to extrapolations of future mass loss and sea-level rise, underscoring the need for continuous long-term satellite monitoring.

A new NASA and university analysis of ocean data collected more than 135 years ago by the crew of the HMS Challenger oceanographic expedition provides further confirmation that human activities have warmed our planet over the past century.

Models of carbon dioxide in the world's oceans need to be revised, according to new work by UC Irvine and other scientists published online Sunday in Nature Geoscience. Trillions of plankton near the surface of warm waters are far more carbon-rich than has long been thought, they found. Global marine temperature fluctuations could mean that tiny Prochlorococcus and other microbes digest double the carbon previously calculated. Carbon dioxide is the leading driver of disruptive climate change.

The climate is getting warmer, and sea levels are rising -- a threat to island nations. As a group of researchers led by colleagues from the University of Bonn found out, at the same time, tiny single-cell organisms are spreading rapidly through the world's oceans, where they might be able to mitigate the consequences of climate change. Foraminifera of the variety Amphistegina are stabilizing coastlines and reefs with their calcareous shells.

Historic lake sediment dug up by University of Pittsburgh researchers reveals that oceanic influences on rainfall in Central America have varied over the last 2,000 years, highlighting the fluctuating influence the Atlantic and Pacific Oceans have on precipitation.

Now, a new paper published recently in the journal Geophysical Research Letters documents the effects of the 2010-11 La Niña on global sea level and updates the measurements. The result: as predicted, by mid-2012, global mean sea level had not only recovered from the more than 0.2 inches (5 millimeters) it dropped in 2010-11, but had resumed its long-term mean annual rise of 0.13 inches (3.2 millimeters) per year. Results of the new study are presented graphically at: http://photojournal.jpl.nasa.gov/catalog/PIA16294.

Anthropogenic climate change leads to melting glaciers and rising sea level. Between 1902 and 2009, melting glaciers contributed 11 cm to sea level rise. They were therefore the most important cause of sea level rise. This is the result of a new assessment by scientists of the University of Innsbruck. They numerically modeled the changes of each of the world’s 300,000 glaciers. Until 2100, glaciers could lead to an additional 22 cm of sea level rise.

Climate scientists agree there have been a lot of strong hurricanes lately. They agree that warmer seas have given these storms some extra punch. But they disagree how much global warming is to blame.

To demonstrate Mazria’s point, Architecture 2030 has compiled a report that features images depicting the dramatic effects of sea level rise — from about 3 to 16 feet — on 21 cities around the country.

Historically, the Northwest Passage linking the Atlantic and Pacific Oceans has been ice-bound through the year.
But the agency says ice cover has been steadily shrinking, and this summer’s reduction has made the route navigable.

A Duke University-led analysis of available records shows that while the North Atlantic Ocean’s surface waters warmed in the 50 years between 1950 and 2000, the change was not uniform. In fact, the subpolar regions cooled at the same time that subtropical and tropical waters warmed.

To date climate change projections, as published in the last IPCC report, only considered changes in future atmospheric composition. This strategy is appropriate for long-term changes in climate such as predictions for the end of the century. However, in order to predict short-term developments over the next decade, models need additional information on natural climate variations, in particular associated with ocean currents.

Scientists have long known that atmospheric convection in the form of hurricanes and tropical ocean thunderstorms tends to occur when sea surface temperature rises above a threshold. The critical question is, how do rising ocean temperatures with global warming affect this threshold? If the threshold does not rise, it could mean more frequent hurricanes.

Scientists from the Woods Hole Oceanographic Institution (WHOI) have conducted a new study to measure levels of carbon at various depths in the Arctic Ocean. The study, recently published in the journal Biogeosciences, provides data that will help researchers better understand the Arctic Ocean's carbon cycle -- the pathway through which carbon enters and is used by the marine ecosystem. It will also offer an important point of reference for determining how those levels of carbon change over time, and how the ecosystem responds to rising global temperatures.

Comparing detailed measurements taken during the Australian Antarctic program's 2012 Southern Ocean marine science voyage to historical data dating back to 1970, scientists estimate there has been as much as a 60 per cent reduction in the volume of Antarctic Bottom Water, the cold dense water that drives global ocean currents.

In a paper just published in the journal Science, Australian scientists from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Lawrence Livermore National Laboratory, California, reported changing patterns of salinity in the global ocean during the past 50 years, marking a clear fingerprint of climate change.

"At this point we can only speculate as to how the mercury enters the river systems, but it appears that climate change may play a large role," says Jacob. "As global temperatures rise, we begin to see areas of permafrost thawing and releasing mercury that was locked in the soil; we also see the hydrological cycle changing, increasing the amount of runoff from precipitation that enters the rivers."

A new study from the Bjerknes Centre explains decadal variations in the oceanic circulation south of Greenland and Iceland. (this report is referenced to help us understand ocean currents and thus be able to better understand any change in those currents due to climate change)

New research by a team of Lawrence Livermore National Laboratory scientists and international collaborators shows that the observed ocean warming over the last 50 years is consistent with climate models only if the models include the impacts of observed increases in greenhouse gas during the 20th century.

To discover how the situation has changed since the last ice age, researchers studied 20,000-year-old mud samples from the sub-Arctic Pacific Ocean lying approximately three feet below the present sea bed. They found the water in the ocean’s depths exchanged less CO2 with the atmosphere than it does at present, while capturing more atmospheric CO2 than the water does today, suggesting as oceans become warmer as a result of climate change they release more carbon dioxide into the atmosphere. [posted by NewsDaily on January 24, 2008]

The upper layer of the world’s ocean has warmed since 1993, indicating a strong climate change signal, according to a new study. The energy stored is enough to power nearly 500 100-watt light bulbs per each of the roughly 6.7 billion people on the planet.

The Atlantic overturning circulation is a system of currents, including the Gulf Stream, that bring warm surface waters from the tropics northward into the North Atlantic. There, in the seas surrounding Greenland, the water cools, sinks to great depths and changes direction. What was once warm surface water heading north turns into cold deep water going south. This overturning is one part of the vast conveyor belt of ocean currents that move heat around the globe.

Scientists have long known that atmospheric convection in the form of hurricanes and tropical ocean thunderstorms tends to occur when sea surface temperature rises above a threshold. The critical question is, how do rising ocean temperatures with global warming affect this threshold? If the threshold does not rise, it could mean more frequent hurricanes.

Sea levels around the world can be expected to rise by several metres in coming centuries, if global warming carries on. Even if global warming is limited to 2 degrees Celsius, global-mean sea level could continue to rise, reaching between 1.5 and 4 metres above present-day levels by the year 2300, with the best estimate being at 2.7 metres, according to a study just published in Nature Climate Change. However, emissions reductions that allow warming to drop below 1.5 degrees Celsius could limit the rise strongly.

Rising sea levels cannot be stopped over the next several hundred years, even if deep emissions cuts lower global average temperatures, but they can be slowed down, climate scientists said in a study on Sunday. (posted by NewsDaily for July 1, 2012).

In research results published online July 5 in the journal Science, scientists report evidence of another trigger. Not sunlight, but whirlpools, or eddies, that swirl across the surface layer of the North Atlantic Ocean. These eddies sustain phytoplankton in the ocean's shallower waters where they can get plenty of sunlight to fuel growth, thereby keeping them from being pushed downward by the vagaries of rough processes at the ocean surface.

Towards the end of the last ice age, at the time of mammoths and primitive humans, the climate naturally warmed. This started to melt ice at increasingly high elevations, eventually reaching and melting the saddle area between the ice domes. This triggered a vicious circle in which the melting saddle would lower, reach warmer altitudes and melt even more rapidly until the saddle had completely melted. In just 500 years, the saddles disappeared and only the ice domes remained.

In fact, the Arctic may have been colder during the Eemian, with lower heat transfer from the North Atlantic. On the basis of their finding, the authors suggest that previous records may reflect other phenomena and caution against the use of the Eemian as an analog of the present. Their finding also challenges climate models that predict extreme warmth and ice-free conditions in the Arctic in response to greenhouse gas warming in the 21st century.

Climate Change and the Sky

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 16:07:00 +0000

This page gives links to science articles about the sky and changes to climate.

In the tropics at heights more than 10 miles above the surface, the prevailing winds alternate between strong easterlies and strong westerlies roughly every other year. This slow heartbeat in the tropical upper atmosphere, referred to as the quasibiennial oscillation (QBO), impacts the winds and chemical composition of the global atmosphere and even the climate at Earth's surface.

University of Manchester scientists, writing in the journal Nature Geoscience, have shown that natural emissions and humanmade pollutants can both have an unexpected cooling effect on Earth's climate by making clouds brighter.

A University of Utah study suggests something amazing: Periodic changes in winds 15 to 30 miles high in the stratosphere influence the seas by striking a vulnerable "Achilles heel" in the North Atlantic and changing mile-deep ocean circulation patterns, which in turn affect Earth's climate.

Floating overhead are mysterious arbiters of our climate. Clouds do more than just deliver rain and snow: by absorbing and reflecting light, they help control the flow of energy around the planet….

When researchers observe natural changes in clouds and temperature, they have traditionally assumed that the temperature change caused the clouds to change, and not the other way around. To the extent that the cloud changes actually cause temperature change, this can ultimately lead to overestimates of how sensitive Earth’s climate is to our greenhouse gas emissions.

By sampling clouds — and making their own — researchers have shown for the first time a direct relation between lead in the sky and the formation of ice crystals that foster clouds. The results suggest that lead generated by human activities causes clouds to form at warmer temperatures and with less water. This could alter the pattern of both rain and snow in a warmer world.

Inside a thunderstorm cloud, warm air rises in updrafts, pushing tiny aerosols from pollution or other particles upwards. Higher up, water vapor cools and condenses onto the aerosols to form droplets, building the cloud. At the same time, cold air falls, creating a convective cycle. Generally, the top of the cloud spreads out like an anvil.

Climate Changes in Greenland

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 15:29:00 +0000

This page gives links to articles about changes to the climate in Greenland.

A first-ever study of air trapped in the deep snowpack of Greenland shows that atmospheric levels of carbon monoxide (CO) in the 1950s were actually slightly higher than what we have today. This is a surprise because current computer models predict much higher CO concentrations over Greenland today than in 1950. Now it appears the opposite is in fact true.

The Greenland ice sheet is melting from below, caused by a high heat flow from the mantle into the lithosphere. This influence is very variable spatially and has its origin in an exceptionally thin lithosphere. Consequently, there is an increased heat flow from the mantle and a complex interplay between this geothermal heating and the Greenland ice sheet. The international research initiative IceGeoHeat led by the GFZ German Research Centre for Geosciences establishes in the current online issue of Nature Geoscience that this effect cannot be neglected when modeling the ice sheet as part of a climate study.

While low, thin cloud cover is just one element within a complex interaction of wind speed, turbulence and humidity, the extra heat energy trapped close to the surface can push temperatures above freezing.

In the period between 130,000 and 115,000 years ago, Earth's climate was warmer than today. But how much warmer was it and what did the warming do to global sea levels? -- as we face global warming in the future, the answer to these questions is becoming very important. New research from the NEEM ice core drilling project in Greenland shows that the period was warmer than previously thought. The international research project is led by researchers from the Niels Bohr Institute and the very important results are published in the scientific journal, Nature.

Future sea level rise due to the melting of the Greenland and Antarctic ice sheets could be substantially larger than estimated in Climate Change 2007, the Fourth Assessment Report of the IPCC, according to new research from the University of Bristol.

Research has shown a decrease in levels of the isotope nitrogen-15 in core samples from Greenland ice starting around the time of the Industrial Revolution. The decrease has been attributed to a corresponding increase in nitrates associated with the burning of fossil fuels.
However, new University of Washington research suggests that the decline in nitrogen-15 is more directly related to increased acidity in the atmosphere.

Scientists have discovered what they think may be another reason why Greenland‘s ice is melting: a thin spot in Earth’s crust is enabling underground magma to heat the ice.

They have found at least one “hotspot” in the northeast corner of Greenland — just below a site where an ice stream was recently discovered.

Every year as the Greenland Ice Sheet melts, the rocky coast rises, explained Michael Bevis, Ohio Eminent Scholar in Geodynamics and professor in the School of Earth Sciences at Ohio State University. Some GPS stations around Greenland routinely detect uplift of 15 mm (0.59 inches) or more, year after year. But a temperature spike in 2010 lifted the bedrock a detectably higher amount over a short five-month period — as high as 20 mm (0.79 inches) in some locations.

A chance discovery of 80-year-old photo plates in a Danish basement is providing new insight into how Greenland glaciers are melting today.

The Greenland ice sheet continues to lose mass and thus contributes at about 0.7 millimeters per year to the currently observed sea level change of about 3 mm per year. This trend increases each year by a further 0.07 millimeters per year. The pattern and temporal nature of loss is complex. The mass loss is largest in southwest and northwest Greenland; the respective contributions of melting, iceberg calving and fluctuations in snow accumulation differing considerably.

Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by NASA and university scientists.

"This past melt season was exceptional, with melting in some areas stretching up to 50 days longer than average," said Dr. Marco Tedesco, director of the Cryospheric Processes Laboratory at The City College of New York (CCNY -- CUNY), who is leading a project studying variables that affect ice sheet melting.

Ice samples pulled from nearly a mile below the surface of Greenland glaciers have long served as a historical thermometer, adding temperature data to studies of the local conditions up to the Northern Hemisphere's climate.
But the method -- comparing the ratio of oxygen isotopes buried as snow fell over millennia -- may not be such a straightforward indicator of air temperature.

An ice island twice the size of Manhattan has broken off from Greenland's Petermann Glacier, according to researchers at the University of Delaware and the Canadian Ice Service. The Petermann Glacier is one of the two largest glaciers left in Greenland connecting the great Greenland ice sheet with the ocean via a floating ice shelf.

For several days this month, Greenland's surface ice cover melted over a larger area than at any time in more than 30 years of satellite observations. Nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its two-mile-thick center, experienced some degree of melting at its surface, according to measurements from three independent satellites analyzed by NASA and university scientists.

Despite the current and rapid melting of the Greenland Ice Sheet, it remains far from certain just when we will have reached a point when scientists will be able to predict its disappearance. Recent research conducted by the University of Copenhagen in conjunction with the Technical University of Denmark (DTU) and the Danish National Survey and Cadastre (KMS) in collaboration with an international team of scientists reports that this is not the first time in recent history that the ice sheet has been in retreat and then stabilised again.

Professor Tedesco noted that these changes jibe with what most of the models predict -- the difference is how quickly this seems to be happening.

The Influence of the Sun

noreply@blogger.com (Allen) — Mon, 25 Jun 2012 14:32:00 +0000

This page gives links to articles that discuss the influence of the sun on changes to our climate.

Climate history and related archeology give solid support to the solar hypothesis. The 20th-century episode, or Modern Warming, was just the latest in a long string of similar events produced by a hyperactive sun, of which the last was the Medieval Warming. [posted by The Times on February 11, 2007]

Earth is heating up lately, but so are Mars, Pluto and other worlds in our solar system, leading some scientists to speculate that a change in the sun’s activity is the common thread linking all these baking events.
Others argue that such claims are misleading and create the false impression that rapid global warming, as Earth is experiencing, is a natural phenomenon. [posted by LiveScience on March 12, 2007]

Our finding of a direct correlation between variations in the brightness of the sun and earthly climate indicators (called “proxies”) is not unique. Hundreds of other studies, using proxies from tree rings in Russia’s Kola Peninsula to water levels of the Nile, show exactly the same thing: The sun appears to drive climate change.

Most leading climate experts don’t agree with Henrik Svensmark, the 49-year-old director of the Center for Sun-Climate Research at the Danish National Space Center in Copenhagen. In fact, he has taken a lot of blows for proposing that solar activity and cosmic rays are instrumental in determining the warming (and cooling) of Earth. His studies show that cosmic rays trigger cloud formation, suggesting that a high level of solar activity—which suppresses the flow of cosmic rays striking the atmosphere—could result in fewer clouds and a warmer planet. This, Svensmark contends, could account for most of the warming during the last century. Does this mean that carbon dioxide is less important than we’ve been led to believe? Yes, he says, but how much less is impossible to know because climate models are so limited.

To help nail down the effect of solar radiation, geophysicist Mike Lockwood of the University of Southampton, U.K., examined data available since 1955 on the monthly average output of the sun, including sunspots, magnetic activity, and cosmic-ray variations. Then he compared those data, month by month, with average global temperature records, as well as El Niño- and La Niña-induced weather cycles and the atmospheric effects of major volcanic eruptions. The result, Lockwood and colleagues report in two papers published online this week in the Proceedings of the Royal Society A, is that for the past half-century, the sun has exerted only a small influence on climate–about 3% compared with the warming influence of greenhouse gases and natural climate cycles (see illustration).

The sun has powered almost everything on Earth since life began, including its climate. The sun also delivers an annual and seasonal impact, changing the character of each hemisphere as Earth’s orientation shifts through the year. Since the Industrial Revolution, however, new forces have begun to exert significant influence on Earth’s climate.

Global warming is mainly caused by greenhouse gas emissions resulting from human activities; however, current climatic variations may be affected “around 15% or 20%” by solar activity, according to Manuel Vázquez, a researcher from the Canary Islands’ Astrophysics Institute (IAC) who spoke at the Sun and Climate Change conference, organised as part of the El Escorial summer courses by Madrid’s Complutense University.

The hypothesis they tested was that increased solar activity reduces cloudiness by changing cosmic rays. So, when clouds decrease, more sunlight is let in, causing the earth to warm. Some climate change skeptics have tried to use this hypothesis to suggest that greenhouse gases may not be the global warming culprits that most scientists agree they are.

Establishing a key link between the [11 year] solar cycle and global climate, research led by scientists at the National Science Foundation (NSF)-funded National Center for Atmospheric Research (NCAR) in Boulder, Colo., shows that maximum solar activity and its aftermath have impacts on Earth that resemble La Niña and El Niño events in the tropical Pacific Ocean.

The amount of energy the sun puts out varies over an 11-year cycle (this cycle also governs the appearance of sunspots on the sun’s surface as well as radiation storms that can knock out satellites), but that cycle changes the total amount of energy reaching Earth by only about 0.1 percent. A conundrum for meteorologists was explaining whether and how such a small variation could drive major changes in weather patterns on Earth. [posted by LiveScience on August 27, 2009]

Although Earth's surface overall continues to warm, the new analysis has revealed a correlation between periods of low activity of the Sun and of some cooling -- on a limited, regional scale in Central Europe, along the Rhine.