Tag Archives: global warming

Sailing in a Sea of Microbes

Researchers led by Matt Sullivan at the UA are among the first to dive into the world of viruses drifting through the world’s oceans.

Surrounded by the deep blue of the Pacific Ocean stretching from horizon to horizon, a lonely dot is glinting in the sun. It is the aluminum hull of a sailboat, a 118-foot schooner with white sails billowing from two masts.

On the deck, crewmembers and scientists are milling about. Commands are flying back and forth, and soon a strange contraption consisting of tubes clustered around an array of sensors dangling from a crane is lowered into the water, until it disappears in the clear blue depths. (more…)

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NASA Satellite Finds Earth’s Clouds are Getting Lower

Earth’s clouds got a little lower — about one percent on average — during the first decade of this century, finds a new NASA-funded university study based on NASA satellite data. The results have potential implications for future global climate.

Scientists at the University of Auckland in New Zealand analyzed the first 10 years of global cloud-top height measurements (from March 2000 to February 2010) from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA’s Terra spacecraft. The study, published recently in the journal Geophysical Research Letters, revealed an overall trend of decreasing cloud height. Global average cloud height declined by around one percent over the decade, or by around 100 to 130 feet (30 to 40 meters). Most of the reduction was due to fewer clouds occurring at very high altitudes. (more…)

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Russian River Water Unexpected Culprit Behind Arctic Freshening

A hemispherewide phenomenon – and not just regional forces – has caused record-breaking amounts of freshwater to accumulate in the Arctic’s Beaufort Sea.

Frigid freshwater flowing into the Arctic Ocean from three of Russia’s mighty rivers was diverted hundreds of miles to a completely different part of the ocean in response to a decades-long shift in atmospheric pressure associated with the phenomenon called the Arctic Oscillation, according to findings published in the Jan. 5 issue of Nature. (more…)

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UChicago Chemist Helps Craft Message For World Leaders

Dmitri Talapin, associate professor in chemistry, was one of 10 young scientists from around the world who delivered a message that “Scientific Research is a Global Necessity” to political, scientific and business leaders participating in the 2011 Science and Technology in Society forum last October in Kyoto, Japan.

The Japan Society for the Promotion of Science and the New York Academy of Sciences selected Talapin to represent the young scientists of North America at the STS Forum, which meets at the same venue were the Kyoto Protocol to alleviate global warming was signed in 1997. (more…)

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Powerful Mathematical Model Greatly Improves Predictions for Species Facing Climate Change

UCLA life scientists and colleagues have produced the most comprehensive mathematical model ever devised to track the health of populations exposed to environmental change.

The research, federally funded by the National Science Foundation, is published Dec. 2 in the journal Science.

The team’s groundbreaking integral projection model, or IPM, unites various sub-disciplines of population biology, including population ecology, quantitative genetics, population genetics, and life-span and offspring information, allowing researchers to link many different data sources simultaneously. Scientists can now change just a single variable, like temperature, and see how that affects many factors for a population. (more…)

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Deforestation Causes Cooling in northern U.S., Canada

Deforestation, considered by scientists to contribute significantly to global warming, has been shown by a Yale-led team to actually cool the local climate in northern latitudes, according to a paper published Nov. 17 in Nature.

“If you cut trees in the boreal region, north of 45 degrees latitude, you have a net cooling effect,” says Xuhui Lee, the study’s principal investigator and professor of meteorology at the Yale School of Forestry & Environmental Studies. “You release carbon into the atmosphere by cutting down trees, but you increase the albedo effect — the reflection of sunlight.” (more…)

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Book Traces Long Trail of Global Warming Scholarship

Geophysical Sciences Professor David Archer polled the 200 students in one of his Global Warming classes about whether they believed that humans have had an impact on climate. Approximately 90 percent of the students responded “yes,” reflecting the lessons of climate simulations that Archer had shared earlier with the students.

Those computer simulations are able to reproduce the trend toward rising temperatures, but only when they include data on rising carbon dioxide concentrations in the atmosphere. Simulations that omit the CO2 data do not accurately reproduce the changes. Archer says the link helps reveal carbon dioxide emissions as “the smoking gun” behind global warming and climate change. (more…)

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Water Evaporated from Trees Cools Global Climate

Washington, DC — Scientists have long debated about the impact on global climate of water evaporated from vegetation. New research from Carnegie’s Global Ecology department concludes that evaporated water helps cool the earth as a whole, not just the local area of evaporation, demonstrating that evaporation of water from trees and lakes could have a cooling effect on the entire atmosphere. These findings, published September 14 in Environmental Research Letters, have major implications for land-use decision making.

Evaporative cooling is the process by which a local area is cooled by the energy used in the evaporation process, energy that would have otherwise heated the area’s surface. It is well known that the paving over of urban areas and the clearing of forests can contribute to local warming by decreasing local evaporative cooling, but it was not understood whether this decreased evaporation would also contribute to global warming (more…)

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