Scientific American

A Tour of the New Geopolitics of Global Warming

Mon, 02 Apr 2012 12:00:00 EST

Energy security and climate change present massive threats to global security, military planners say, with connections and consequences spanning the world.

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Radioactive Iodine from Fukushima Found in California Kelp

Fri, 30 Mar 2012 12:35:00 EST

LONG BEACH, Calif. – Kelp off Southern California was contaminated with short-lived radioisotopes a month after Japan’s Fukushima accident, a sign that the spilled radiation reached the state’s urban coastline, according to a new scientific study.

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'Earth Hour' Pauses at U.S. Border

Fri, 30 Mar 2012 11:00:00 EST

Consider an hour without power, from 8:30 to 9:30 p.m. Saturday, local time. Organizers say as many as 1.8 billion will join in the symbolic environmental event worldwide. But if you live in the US, your neighbors may think you just blew a fuse.

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Primeval Precipitation: What Fossil Imprints of Rain Reveal about Early Earth

Wed, 28 Mar 2012 15:01:00 EST

Some 2.7 billion years ago in what is now Omdraaisvlei farm near Prieska, South Africa, a brief storm dropped mild rain on a new layer of ash laid down by a recent volcanic eruption (not unlike ash from the 2010 Eyjafjallajökull eruptio n in Iceland) forming tiny craters. Additional ash subsequently buried the craters and, over eons, hardened to become rock known as tuff. Closer to the present, other rainstorms eroded the overlying tuff, exposing a fossil record of raindrops from the Archean eon, and may now have revealed the density of early Earth's atmosphere.

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Pupfish, Downfish: Subterranean Tsunami Gives Vertical Shakes to the Water-Hole Home of Endangered Fishes

Tue, 27 Mar 2012 11:00:00 EST

On March 20 a National Park Service biologist named Jeffrey Goldstein and I descended a rocky incline into the mouth of Devils Hole, a collapsed cave in the Nevada desert 40 miles south of the visitor’s center in Death Valley. Thirty feet down, an arm of water extends out from a deep pool to cover a rock shelf the size of a Ping-Pong table with up to two and a half feet of hot water. This shallow recess is home to 100 much-studied adult Devils Hole pupfish, or Cyprinodon diabolis . Living nowhere else on the planet, the pupfish receive protection from human harm by force of federal law and padlocked gates.

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Big Kill, Not Big Chill, Finished Off Giant Kangaroos

Thu, 22 Mar 2012 14:31:00 EST

Around 40,000 years ago, the giant kangaroo disappeared from Australia. So did Diprotodon ( rhinoceros-size wombats ) and Palorchestes ( tapirlike marsupials ) as well as supersize birds, reptiles and some 50 other so-called megafauna--big animals. And now a record of fungal spores pulled from the swamp at Lynch's Crater in the northeastern corner of the continent reveals humans as the culprit. [More]

First of Our Kind: Could Australopithecus sediba Be Our Long Lost Ancestor? (preview)

Tue, 20 Mar 2012 10:45:00 EST

Sometime between three million and two million years ago, perhaps on a primeval savanna in Africa, our ancestors became recognizably human. For more than a million years their australopithecine predecessors--Lucy and her kind, who walked upright like us yet still possessed the stubby legs, tree-climbing hands and small brains of their ape forebears--had thrived in and around the continent’s forests and woodlands. But their world was changing. Shifting climate favored the spread of open grasslands, and the early australopithecines gave rise to new lineages. One of these offshoots evolved long legs, toolmaking hands and an enormous brain. This was our genus, Homo , the primate that would rule the planet.

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Worm Discovery Illuminates How Our Brains Might Have Evolved

Thu, 15 Mar 2012 07:30:00 EST

Our earliest invertebrate ancestors did not have brains. Yet, over hundreds of millions of years, we and other vertebrates have developed amazingly complicated mental machinery. "It must have evolutionary roots somewhere, but where?" wrote Henry Gee, an editor at Nature, in an essay published in the journal's March 15 issue. ( Scientific American is part of Nature Publishing Group.)

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Fukushima Anniversary: We Listen Back

Sun, 11 Mar 2012 14:15:08 EST

Scientific American editor David Biello takes us through newly released audio from the first week of the nuclear meltdown crisis at Fukushima Daiichi.

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Fukushima: We Listen Back

Sun, 11 Mar 2012 14:00:08 EST

Welcome to a special longer edition of the Scientific American podcast 60-Second Earth:

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How Safe Are U.S. Nuclear Reactors? Lessons from Fukushima

Fri, 09 Mar 2012 08:01:00 EST

The meltdown started when water to cool the reactors fell to dangerously low levels four hours after the fourth-largest recorded earthquake rattled the Fukushima Daiichi nuclear power plant . Five out of six of its reactors lost electricity when a 14-meter tall tsunami swept in 40 minutes later. Backup diesel generators lost their fuel tanks and died. Cooling water pumps failed. Nuclear fuel rods began melting and volatile hydrogen gas built up . Subsequent explosions and fire spewed 15,000 terabecquerels of radioactive cesium 137 alone, enough so that officials created an " exclusion zone " of 20 kilometers around the plant that persists today. (A becquerel is a unit of the rate of radioactive decay--or radiation emitted by a substance.) As a result, the emergency at Fukushima Daiichi that began on March 11, 2011, is only the second nuclear accident to merit the most severe international crisis rating , joining the reactor that exploded at the Soviet Union's Chernobyl nuclear facility in Ukraine April 1986.

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Finding the Flotsam: Where Is Japan's Floating Tsunami Wreckage Headed? [Video]

Mon, 05 Mar 2012 11:00:00 EST

When the 10-meter-high tsunami wave that followed the March 2011 magnitude 9.0 earthquake in Japan receded, it took with it some 23 million metric tons of material, including pieces of buildings, wood, plastics and more. Whereas most of the wreckage sank to the ocean floor, some of it is still floating toward other Pacific nations . The "debris field"--the visible wave of material--has dissipated, leaving the junk invisible to satellites.

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Japan Tsunami Rubble May Be Headed for Hawaii

Mon, 05 Mar 2012 10:59:00 EST

The earthquake and tsunami that struck Japan last March created an estimated 25 million tons of debris, large amounts of which washed into the ocean. Soon after the disaster, satellites photographed and tracked large mats of wreckage--building parts, boats and household objects--floating off the Japanese coast. Now, according to computer models developed by Nikolai Maximenko and his colleagues at the University of Hawaii and at the U.S. National Oceanic and Atmospheric Administration, the detritus is on course to reach the northwestern Hawaiian Islands early this year.

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March 2012 Advances: Additional Resources

Sun, 04 Mar 2012 07:00:00 EST

The Advances section of Scientific American 's March issue discusses how reducing soot emissions could be a quick, if temporary, fix for global warming; explains why cramming for tests doesn't work; and examines physicists' latest efforts to make an object disappear. To learn more about these, and all our other stories, click on the links below.

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Japan's Post-Fukushima Earthquake Health Woes Go Beyond Radiation Effects

Fri, 02 Mar 2012 15:40:00 EST

After the March 11, 2011, earthquake and tsunami crippled Japan's Fukushima Daiichi nuclear power plant, worry about the unfolding nuclear accident quickly commandeered international headlines. Even after the situation was brought under relative control over subsequent days and weeks, public concern hung on the threat of radiation almost more than it did than on the tsunami and earthquake themselves, which had killed more than 15,850 people and displaced at least 340,000 more.

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It's Not Just Fukushima: Mass Disaster Evacuations Challenge Planners

Fri, 02 Mar 2012 09:01:00 EST

On March 11, 2011, Japan suffered a massive earthquake and subsequent tsunami that destroyed roads, bridges, and buildings; killed nearly 16,000 people; and critically disabled three reactors at the Fukushima Daiichi nuclear power plant. By March 12, the U.S. Nuclear Regulatory Commission (NRC) was already considering urging Americans within 50 miles of the stricken nuclear reactors to evacuate, given an explosion in Unit 1 that destroyed the reactor building and exposed spent nuclear fuel and other radioactive materials to the air.

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How Raindrops Calm the Wind

Sun, 26 Feb 2012 09:00:08 EST

Rain isn't just a soothing sound. It also helps calm the winds. How? Friction.

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One Scientist's Journey to the Ocean Floor

Sun, 26 Feb 2012 08:00:00 EST

Name: Jill McDermott [More]

"Hockey Stick" Scientist Cross-Checks Critics: A Q&A with Michael E. Mann (preview)

Wed, 22 Feb 2012 07:00:00 EST

Climatologist Michael E. Mann is most famous for what he calls one of the “least interesting” aspects of his work. In the 1990s he used data from tree rings, coral growth bands and ice cores as proxies for ancient temperatures, combining them with modern thermometer readings. This annual record of temperature variations over the past millennium offered insights into natural climate cycles. As an “afterthought,” he included a graph of average temperatures in the Northern Hemisphere going back to the 1400s in a 1998 paper (he later extended it to A.D. 1000). That “hockey stick” graph, which shows temperatures bouncing up and down before rapidly rising more recently, became an icon of climate change.

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Fossilized, 'Pompeii' Forest Discovered Under Ash

Tue, 21 Feb 2012 15:30:00 EST

About 300 million years ago, volcanic ash buried a tropical forest located in what is now Inner Mongolia, much like it did the ancient Roman city of Pompeii.

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