March 2, 2007, 5:02 AM CT

Heatwave on the top of the world

The French Intergovernmental Panel on Climate Change (IPPC, or GIEC in French) has just announced the conclusions of its 4th report, which restates that global warming has increased the average temperature by 0.74C over the last century. However, there is very little information about some parts of the planet, such as central Asia. A new study by French scientists from the Laboratory of Glaciology and Geophysics of the Environment (LGGE, CNRS / Universit Joseph Fourier, Grenoble, France) and the Laboratory of Sciences of the Cliamte and the Environment (LSCE / IPSL, CEA / CNRS / Universit de Versailles Saint-Quentin, France), in collaboration with Chinese, Russian and American researchers, proves that the recent warming has also affected the ice cap on Mount Everest, in the heart of the Himalayas. This result was published on February 7, 2007 in the European Journal "Climate of the Past".

Relatively little is known about climate change in the Himalayas and the Tibetan plateau. There are very few meteorological stations, and instrumental records from glaciers, lakes or tree growth rings are rare and difficult to interpret. However, in 2001 and 2002, Chinese researchers drilled three ice cores in the eastern summit of the East Rongbuk glacier that covers the north pass of Mount Everest, at 6518 meters above sea level. These ice cores were analyzed in collaboration with the LGGE and the LSCE, and they have shown that a new climate marker exists, the ice core gas content, which can reconstruct the changes in summer temperatures on this very high site......... Posted by: Tyler      Read more         Source

March 2, 2007, 5:00 AM CT

Rethinking Strategies For Soot Emission

Carnegie Mellon University scientists say government officials need to adopt new ways of measuring and regulating the fine particles of smoke and soot so endemic to serious health problems and the global warming crisis.

In a March 2 article reported in the journal Science, professors Allen L. Robinson and Neil M. Donahue report a new conceptual model for how microscopic particles behave in the atmosphere that raises new questions about current regulations.

The research found new chemical processes that occur after soot and gaseous pollutants are emitted from cars and trucks, changing the chemical and physical properties of the soot particles and creating new particulate matter. These new particles are potentially more toxic and may have a stronger influence on cloud formation that can alter the global climate.

"One of our key findings is that this chemical processing leads to more particulate matter in the air, meaning that regulators are likely underestimating how sources such as cars and trucks contribute to pollution," said Robinson, an associate professor of mechanical engineering and engineering and public policy. "We need to take a holistic approach to regulating these sources that account for all emissions." Accounting for these new processes improves the predictions of the models federal and state governments use to develop regulations......... Posted by: Tyler      Read more         Source

February 28, 2007, 9:51 PM CT

Through Precariously Balanced Rocks

A seismological research team from the University of Nevada, Reno is finding ways to make precariously balanced rocks talk. In so doing, they are unlocking valuable scientific information in assessing seismic hazards in areas throughout the West.

Their findings are shared in the January-recent issue of American Scientist magazine. Researchers think that zones of precarious rocks rocks that have come close but haven't tipped over in the wake of a major seismic event provide important information about seismic risk, its magnitude and its frequency.

"There's really no long-term data to test seismic hazards other than precarious rocks," said Matthew Purvance, a postdoctoral scholar in geophysics at the University, who authored the article along with James Brune, professor in the Department of Geological Sciences and past director of the Nevada Seismological Laboratory, and Rasool Anooshehpoor, research professor in the Nevada Seismological Laboratory.

"By studying precariously balanced rocks, it can serve as an indicator that an earthquake of a sufficient size to topple a tippy rock has not occurred at least for a very long time. We think this is a fundamental story that gives fundamental information on seismic hazards that has never been done before"......... Posted by: Tyler      Read more         Source

February 28, 2007, 9:49 PM CT

Through Precariously Balance Rocks

A seismological research team from the University of Nevada, Reno is finding ways to make precariously balanced rocks talk. In so doing, they are unlocking valuable scientific information in assessing seismic hazards in areas throughout the West.

Their findings are shared in the January-recent issue of American Scientist magazine. Researchers think that zones of precarious rocks rocks that have come close but haven't tipped over in the wake of a major seismic event provide important information about seismic risk, its magnitude and its frequency.

"There's really no long-term data to test seismic hazards other than precarious rocks," said Matthew Purvance, a postdoctoral scholar in geophysics at the University, who authored the article along with James Brune, professor in the Department of Geological Sciences and past director of the Nevada Seismological Laboratory, and Rasool Anooshehpoor, research professor in the Nevada Seismological Laboratory.

"By studying precariously balanced rocks, it can serve as an indicator that an earthquake of a sufficient size to topple a tippy rock has not occurred at least for a very long time. We think this is a fundamental story that gives fundamental information on seismic hazards that has never been done before"......... Posted by: Tyler      Read more         Source

February 26, 2007, 7:06 PM CT

Northwest Atlantic Ocean Ecosystems

Ecosystems along the continental shelf waters of the Northwest Atlantic Ocean--from the Labrador Sea south of Greenland all the way to North Carolina--are experiencing large, rapid changes, report oceanographers funded by the National Science Foundation (NSF) in the Feb. 23, 2007, issue of the journal Science.

While some researchers have pointed to the decline of cod from overfishing as the main reason for the shifting ecosystems, the paper emphasizes that climate change is also playing a big role.

"It is becoming increasingly clear that Northwest Atlantic ecosystems are being affected by climate forcing from the bottom up and overfishing from the top down," said Charles Greene, an oceanographer at Cornell University in Ithaca, N.Y, and lead author of the Science paper. "Predicting the fate of these ecosystems will be one of oceanography's grand challenges for the 21st century".

Most researchers believe humans are warming the planet by burning fossil fuels and changing land surfaces. Early signs of this warming have appeared in the Arctic. Since the late 1980s, researchers have noticed that pulses of fresh water from increased precipitation and melting of ice on land and sea in the Arctic have flowed into the North Atlantic Ocean and made the water less salty......... Posted by: Tyler      Read more         Source

February 21, 2007, 8:56 PM CT

Air Purifiers That Emit Ozone

ndoor air purifiers that produce even small quantities of ozone may actually make the air dirtier when used at the same time as household cleaning products, scientists at UC Irvine have discovered.

Ozone emitted by purifiers reacts in the air with unsaturated volatile organic compounds such as limonene - a chemical added to cleaning supplies that gives them a lemon fragrance - to create additional microscopic particles, scientists found. Certain ionic purifiers emit ozone as a byproduct of ionization used for charging airborne particles and electrostatically attracting them to metal electrodes. Ozonolysis purifiers emit ozone at higher levels on purpose with the ostensible goal of oxidizing volatile organic compounds in the air.

This research appeared online this morning in Environmental Science and Technology.

"The public needs to be aware that every air purification approach has its limitation, and ionization air purifiers are no exception," said Sergey Nizkorodov, assistant professor of chemistry at UCI and co-author of the study. "These air purifiers can not only elevate the level of ozone, a formidable air pollutant in itself, but also increase the amount of harmful particulate matter in indoor air".

High levels of airborne particles can aggravate asthma and cardiovascular problems, and have been linked to higher death and lung cancer rates. Excess ozone can damage the lungs, causing chest pain, coughing, shortness of breath and throat irritation......... Posted by: Tyler      Read more         Source

February 19, 2007, 8:16 PM CT

Economics Of Climate Change

Sir Nicholas Stern's report on the economics of climate change was a political document rather than a scientific one. It's based on some significantly flawed scientific premises--to a degree likely to undercut the report's credibility, in some circles at least.

But the report was significant for being produced at all--as the first attempt by a major national government to identify climate change "as an urgent and serious issue," as Paul L. Joskow, professor of economics, put it, and to quantify its costs.

These were some of the conclusions of an IAP presentation, "The Economic Impacts of Climate Change: a Discussion of the Stern Review," given Feb. 1, with Robert Solow, professor of economics emeritus, moderating.

The Stern report, commissioned by British Chancellor of the Exchequer Gordon Brown, and produced by a former chief economist of the World Bank, was released Oct. 30, 2006. It captured headlines with two critical numbers: 1 percent and 20 percent.

Global warming, left unchecked, could lead to the permanent loss of up to 20 percent of gross world product annually well out into the future, Stern warned. Conversely, the cost of mitigating action to avoid the worst effects of climate change could be confined to only 1 percent of global GDP, he suggested......... Posted by: Tyler      Read more         Source

February 19, 2007, 7:12 PM CT

Air Contaminants Databases

ir pollution sources are everywhere in the home, from the bacon and eggs frying in the kitchen, to the woodburning stove in the family room, the newly painted hallway, and even the carpet in the living room. To help estimate the seriousness of these and other indoor pollutant sources as well as to devise ways to reduce possible health impacts, the National Institute of Standards and Technology (NIST) has developed searchable databases of relevant product emission studies.

NIST scientists also have created a software tool called ContamLink that can transfer selected information from the databases into CONTAM, an indoor air quality modeling software program that predicts airflows and contaminant concentrations in multizone building systems. Together-the electronic databases, ContamLink, and the CONTAM program-should significantly accelerate our understanding of indoor air pollution.

The new databases allow researchers to access immediately information that previously was available in scientific literature, but mandatory significant time to locate. The databases include emission rates for consumer products, cooking and combustion appliances (such as gas stoves); and data on contaminant transport mechanisms, including particle deposition, contaminant sorption and different ventilation systems filters. Two of the five databases are from the U.S. Environmental Protection Agency (EPA) and the National Research Council of Canada. Scientists can download the databases, and with ContamLink, selectively obtain relevant information for inclusion in CONTAM or other indoor air quality models. Database entries are not intended to be all-inclusive, but rather representative of the literature. Scientists and other practitioners are encouraged to expand the databases with their own data using the data entry format provided......... Posted by: Tyler      Read more         Source

February 13, 2007, 9:56 PM CT

Warmer Future Could Bring Droughts

NASA scientists may have discovered how a warmer climate in the future could increase droughts in certain parts of the world, including the southwest United States.

The researchers compared historical records of the climate impact of changes in the sun's output with model projections of how a warmer climate driven by greenhouse gases would change rainfall patterns. They found that a warmer future climate likely will produce droughts in the same areas as those observed in ancient times, but potentially with greater severity.

"These findings strongly suggest that greenhouse gases and long-term changes in solar activity both can have major influences on climate via similar processes," said Drew Shindell, NASA Goddard Institute for Space Studies, New York. Shindell is lead author of a paper that appeared in the Dec. 27, 2006, issue of the American Geophysical Union's "Geophysical Research Letters."

"There is some evidence that rainfall patterns already may be changing," Shindell added. "Much of the Mediterranean area, North Africa and the Middle East rapidly are becoming drier. If the trend continues as expected, the consequences may be severe in only a couple of decades. These changes could pose significant water resource challenges to large segments of the population."........ Posted by: Tyler      Read more         Source

February 12, 2007, 9:27 PM CT

Glaciers not on simple, upward trend of melting

Two of Greenland's largest glaciers shrank dramatically and dumped twice as much ice into the sea during a period of less than a year between 2004 and 2005. And then, less than two years later, they returned to near their prior rates of discharge.

The variability over such a short time, reported online Feb. 9 on Science magazine's Science Express, underlines the problem in assuming that glacial melting and sea level rise will necessarily occur at a steady upward trajectory, as per lead author Ian Howat, a post-doctoral researcher with the University of Washington's Applied Physics Laboratory and the University of Colorado's National Snow and Ice Data Center. The paper comes a year after a study in the journal Science revealed that discharge from Greenland's glaciers had doubled between 2000 and 2005, leading some researchers to speculate such changes were on a steady, upward climb.

"While the rates of shrinking of these two glaciers have stabilized, we don't know whether they will remain stable, grow or continue to collapse in the near future," Howat says. That's because the glaciers' shape changed greatly, becoming stretched and thinned.

"Our main point is that the behavior of these glaciers can change a lot from year to year, so we can't assume to know the future behavior from short records of recent changes," he says. "Future warming may lead to rapid pulses of retreat and increased discharge rather than a long, steady drawdown."........ Posted by: Tyler      Read more         Source