December 15, 2008, 9:28 PM CT

Warming climate signals big changes for ski areas

Rocky Mountain ski areas face dramatic changes this century as the climate warms, including best-case scenarios of shortened ski seasons and higher snowlines and worst-case scenarios of bare base areas and winter rains, says a new Colorado study.

The study indicates snowlines -- elevations below which seasonal snowpack will not develop -- will continue to rise through this century, moving up more than 2,400 feet from the base areas of Colorado's Aspen Mountain and Utah's Park City Mountain by 2100, said University of Colorado at Boulder geography Professor Mark Williams. Williams and Brian Lazar of Stratus Consulting Inc. of Boulder combined temperature and precipitation data for Aspen Mountain and Park City Mountain with general climate circulation models for the study.

The pair came up with three scenarios for each of the two ski havens for the years 2030, 2075 and 2100. The low-emissions scenario is based on the presumption that the world begins reducing CO₂ emissions, said Williams. The "business-as-usual" scenario assumes the future rate of CO₂ increase will be similar to the current rate, while the high-emissions scenario assumes future CO₂ emissions will increase over the present rate.

Their forecasts indicate the "business as usual" scenario will cause average temperatures to rise by nearly 4 degrees Fahrenheit at Aspen and Park City by 2030 and 8.6 degrees F in Aspen and 10.4 degrees F for Park City by 2100, said Williams. A paper by Williams and Lazar was presented at the Fall Meeting of the American Geophysical Union held Dec. 15-19 in San Francisco......... Posted by: Tyler      Read more         Source

December 15, 2008, 9:20 PM CT

Ancient Magma "Superpiles" May Have Shaped The Continents

Two giant plumes of hot rock deep within the earth are associated with the plate motions that shape the continents, scientists have found.

The two superplumes, one beneath Hawaii and the other beneath Africa, have likely existed for at least 200 million years, explained Wendy Panero, assistant professor of earth sciences at Ohio State University.

The giant plumes -- or "superpiles" as Panero calls them -- rise from the bottom of Earth's mantle, just above our planet's core. Each is larger than the continental United States. And each is surrounded by a wall of plates from Earth's crust that have sunk into the mantle.

She and her colleagues reported their findings at the American Geophysical Union meeting in San Francisco.

Computer models have connected the piles to the sunken former plates, but it's currently unclear which one spawned the other, Panero said. Plates sink into the mantle as part of the normal processes that shape the continents. But which came first, the piles or the plates, the scientists simply do not know.

"Do these superpiles organize plate motions, or do plate motions organize the superpiles? I don't know if it's truly a chicken-or-egg kind of question, but the locations of the two piles do seem to be correlation to where the continents are today, and where the last supercontinent would have been 200 million years ago," she said......... Posted by: Tyler      Read more         Source

December 11, 2008, 10:33 PM CT

Better Flight Plan For Weather Forecasting

At MIT, planning for bad weather involves far more than remembering an umbrella. Scientists in the Department of Aeronautics and Astronautics are trying to improve weather forecasting using robotic aircraft and advanced flight plans that consider millions of variables.

"Weather affects huge sectors of our economy, such as agriculture and transportation," said Nicholas Roy, an assistant professor and one of the scientists who worked on the project. With more time for advanced planning, farmers could bring in their crop before a big storm hits. Airlines could adjust their flight schedules further in advance, reducing the impact on customers.

Improving weather forecasting could also save lives. "People do get killed in these storms," said Aero-Astro Professor Jonathan How, the principal investigator. The more time to prepare for a storm and evacuate the area, the better. Currently, forecasts made more than 48 hours in the future aren't considered highly reliable.

The scientists hope to gain some lead-time by improving the way data about current weather conditions are collected. Existing forecasting systems depend on pressure, temperature, and other sensors aboard a single piloted airplane that flies scripted routes. But the data that are collected can't be processed fast enough to alter the flight plan if a storm starts brewing. "The response time is fairly slow," How said. "Today's flight path is based on yesterday's weather"......... Posted by: Tyler      Read more         Source

December 9, 2008, 10:22 PM CT

Climate Change Threat: Developing Countries Lack Efficient Technologies

Contrary to earlier projections, few developing countries will be able to afford more efficient technologies to reduce greenhouse gas emissions in the next few decades, new research concludes. The study, by scientists at the National Center for Atmospheric Research (NCAR) and the University of Colorado, warns that continuing economic and technological disparities will make it more difficult than anticipated to reduce greenhouse gas emissions, and it underscores the challenges that poorer nations face in trying to adapt to global warming.

The study will be published this month in the journal Climate Research. It was funded by the National Science Foundation, NCAR's sponsor.

"There is simply no evidence that developing countries will somehow become wealthier and be in a position to install more environmentally friendly technologies," says Patricia Romero Lankao, an NCAR sociologist who is the lead author of the study. "We always knew that reducing greenhouse gas emissions was going to be a challenge, but now it looks like we underestimated the magnitude of this problem".

As a result, most industrialized and developing countries are increasing their emissions of carbon dioxide. Their economic growth is outstripping the increase in efficiency, and the demand for more cars, larger houses, and other goods and services is leading to ever-increasing emissions of carbon dioxide. A number of of the products these nations consume come from developing countries that are producing more but not gaining the wealth needed to increase efficiency......... Posted by: Tyler      Read more         Source

December 9, 2008, 9:58 PM CT

Causes of death on Mount Everest

An international research team led by Massachusetts General Hospital (MGH) scientists has conducted the first detailed analysis of deaths during expeditions to the summit of Mt. Everest. They found that most deaths occur during descents from the summit in the so-called "death zone" above 8,000 meters and also identified factors that appear to be associated with a greater risk of death, particularly symptoms of high-altitude cerebral edema. The report, which will appear the December 20/27 issue of the British Medical Journal has been released online.

"We know that climbing Everest is dangerous, but exactly how and why people have died had not been studied," says Paul Firth, MB, ChB, of the MGH Department of Anesthesia, who led the study "It had been assumed that avalanches and falling ice particularly in the Khumbu Icefall on the Nepal route were the leading causes of death and that high-altitude pulmonary edema would be a common problem at such extreme altitude. But our results do not support either assumption".

Thousands of climbers have attempted to reach the summit of 8,850-meter (29,000-foot) Mount Everest since the 1920s. In order to examine the circumstances surrounding all deaths on Everest expeditions, the research team which included scientists from three British hospitals and the University of Toronto reviewed available expedition records including the Himalayan Database, a compilation of information from all expeditions to 300 major peaks in the world's highest range. Of a total of reported 212 deaths on Everest from 1921 to 2006, 192 occurred above Base Camp, the last encampment before technical (roped) climbing begins......... Posted by: Tyler      Read more         Source

December 9, 2008, 9:17 PM CT

Building telescope at South Pole

It's 40 degrees F below zero (with the wind chill) at the South Pole today. Yet a research team from the University of Delaware is taking it all in stride.

The physicists, engineers and technicians from the University of Delaware's Bartol Research Institute are part of an international team working to build the world's largest neutrino telescope in the Antarctic ice, far beneath the continent's snow-covered surface.

Dubbed "IceCube," the telescope will occupy a cubic kilometer of Antarctica when it is completed in 2011, opening super-sensitive new eyes into the heavens.

"IceCube will provide new information about some of the most violent and far-away astrophysical events in the cosmos," says Thomas Gaisser, the Martin A. Pomerantz Chaired Professor of Physics and Astronomy at the University of Delaware, and one of the project's lead scientists.

The University of Delaware is among 33 institutions worldwide that are contributing to the National Science Foundation project, which is coordinated by the University of Wisconsin.

Besides taking a turn as "on-ice lead" for this year's IceCube construction effort at the South Pole (or simply "Pole," as the locals call it), Gaisser is managing the University of Delaware's continued deployment of the telescope's surface array of detectors, known as "IceTop"......... Posted by: Tyler      Read more         Source

December 1, 2008, 6:32 PM CT

Speed matters for ice-shelf breaking

It won't help the Titanic, but a newly derived, simple law may help researchers improve their climate models and glaciologists predict where icebergs will calve off from their parent ice sheets, as per a team of Penn State researchers.

"To predict the future of the ice sheet and to understand the past, we have to put the information into a computer," says Richard B. Alley, the Evan Pugh professor of geosciences. "The models we have do not currently have any way to figure out where the big ice sheets end and where the ice calves off to form icebergs".

Ice sheets, such as those in Antarctica and Greenland, spread under their own weight and flow off land over the oceans. The Ross Ice Shelf in Antarctica floats for as much as 500 miles over the ocean before the edges begin to break and create icebergs. Other ice shelves only edge over the water for a mile or two.

"The problem of when things break is a really hard problem because there is so much variability," says Alley. "Anyone who has dropped a coffee cup knows this. Sometimes the coffee cup breaks and sometimes it bounces".

The coffee cup's breaking depends on what it hits and where it hits, but the most important variable is the distance the cup falls or is thrown. Below a certain distance, the cup will always remain intact, while above a certain distance, it will always break; for in-between distances, the results are variable......... Posted by: Tyler      Read more         Source

November 24, 2008, 9:52 PM CT

Light pollution offers new global measure of coral reef health

We've all seen the satellite images of Earth at night--the bright blobs and shining webs that tell the story of humanity's endless sprawl.

These pictures are no longer just symbols of human impact, however, but can be used to objectively measure it, as per a research studyin the December 2008 issue of Geocarto International, a peer-evaluated journal on geoscience and remote sensing.

Travis Longcore, a USC geographer and expert in light pollution, collaborated with an international team, led by Christoph Aubrecht of the Austrian Research Centers, to develop the index.

"Coral reefs are incredibly importantbut unfortunately they're also incredibly fragile," Longcore said. "Using night light proximity, we were able to identify the most threatened and most pristine spots in an objective and easily repeatable way".

The scientists did this by first classifying the light into three separate sources: urban areas, gas flares and fishing boat activity.

Each of these sources puts stress on reefs: urban areas cause sewage and polluted runoff, oil platforms cause leakages and spills, and commercial fishing boats deplete marine life and impair the ecological balance.

The closer a reef is to one or more of these sources, the higher the index number and the greater the stress on the reefs......... Posted by: Tyler      Read more         Source

November 21, 2008, 5:45 AM CT

Pollution at home lurks unrecognized

Eventhough Americans are becoming increasingly aware of toxic chemical exposure from everyday household products like bisphenol A in some baby bottles and lead in some toys, women do not readily connect typical household products with personal chemical exposure and related adverse health effects, as per research from the recent issue of the Journal of Health and Social Behavior

"People more readily equate pollution with large-scale contamination and environmental disasters, yet the products and activities that form the backdrop to our everyday liveselectronics, cleaners, beauty products, food packagingare a significant source of daily personal chemical exposure that accumulates over time," said sociologist Rebecca Gasior Altman, the lead author of the study, "Pollution Comes Home and Gets Personal: Women's Experience of Household Chemical Exposure".

Altman and her team examined how women interpreted and reacted to information about chemical contamination in their homes and bodies. After reviewing their personal chemical exposure data, most women were surprised and puzzled at the number of contaminants detected. They initially had difficulty relating the chemical results for their homes, located in rural and suburban communities, with their images of environmental problems, which they linked to toxic contamination originating outside the home from military or industrial activities, accidents or dumping......... Posted by: Tyler      Read more         Source

November 19, 2008, 8:12 PM CT

Global warming predictions are overestimated

A detailed analysis of black carbon -- the residue of burned organic matter -- in computer climate models suggests that those models may be overestimating global warming predictions.

A new Cornell study, published online in Nature Geosciences, quantified the amount of black carbon in Australian soils and observed that there was far more than expected, said Johannes Lehmann, the paper's lead author and a Cornell professor of biogeochemistry. The survey was the largest of black carbon ever published.

As a result of global warming, soils are expected to release more carbon dioxide, the major greenhouse gas, into the atmosphere, which, in turn, creates more warming. Climate models try to incorporate these increases of carbon dioxide from soils as the planet warms, but results vary greatly when realistic estimates of black carbon in soils are included in the predictions, the study found.

Soils include a number of forms of carbon, including organic carbon from leaf litter and vegetation and black carbon from the burning of organic matter. It takes a few years for organic carbon to decompose, as microbes eat it and convert it to carbon dioxide. But black carbon can take 1,000-2,000 years, on average, to convert to carbon dioxide.

By entering realistic estimates of stocks of black carbon in soil from two Australian savannas into a computer model that calculates carbon dioxide release from soil, the scientists observed that carbon dioxide emissions from soils were reduced by about 20 percent over 100 years, as compared with simulations that did not take black carbon's long shelf life into account......... Posted by: Tyler      Read more         Source