Tag Archives: climate model

Temperature swings may be bigger threat to life than increased warmth

Insects may thrive in the warmer average temperatures predicted by climate models but are threatened by greater temperature variation also anticipated in many areas around the globe, a Yale-led study predicts in the Jan. 29 issue of the Proceedings of the Royal Society of London.

“There has been some thought that many species will do better because of rising average temperatures,” said David Vasseur, associate professor of ecology and evolutionary biology, who headed the study. “But when coupled with greater temperature variations, the story changes.” (more…)

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What are Future Climate Projections for Precipitation and Temperature for Your County?

USGS Website Lets You See

For the first time, maps and summaries of historical and projected temperature and precipitation changes for the 21st century for the continental U.S. are accessible at a county-by-county level on a website developed by the U.S. Geological Survey in collaboration with the College of Earth, Oceanic and Atmospheric Sciences at Oregon State University.

The maps and summaries are based on NASA downscaling of the 33 climate models used in the 5th Climate Model Intercomparison Project and the current Intergovernmental Panel on Climate Change (IPCC) Assessment Report. The resulting NASA dataset is on an 800-meter grid with national coverage.  (more…)

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If a tree falls in Brazil…? Amazon deforestation could mean droughts for western U.S.

In research meant to highlight how the destruction of the Amazon rainforest could affect climate elsewhere, Princeton University-led researchers report that the total deforestation of the Amazon may significantly reduce rain and snowfall in the western United States, resulting in water and food shortages, and a greater risk of forest fires.

The researchers report in the Journal of Climate that an Amazon stripped bare could mean 20 percent less rain for the coastal Northwest and a 50 percent reduction in the Sierra Nevada snowpack, a crucial source of water for cities and farms in California. Previous research has shown that deforestation will likely produce dry air over the Amazon. Using high-resolution climate simulations, the researchers are the first to find that the atmosphere’s normal weather-moving mechanics would create a ripple effect that would move that dry air directly over the western United States from December to February. (more…)

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Climate change: fast out of the gate, slow to the finish

Washington, D.C.— A great deal of research has focused on the amount of global warming resulting from increased greenhouse gas concentrations. But there has been relatively little study of the pace of the change following these increases. A new study by Carnegie’s Ken Caldeira and Nathan Myhrvold of Intellectual Ventures concludes that about half of the warming occurs within the first 10 years after an instantaneous step increase in atmospheric CO2 concentration, but about one-quarter of the warming occurs more than a century after the step increase. Their work is published in Environmental Research Letters.

The study was the result of an unusual collaboration of a climate scientist, Ken Caldeira, who contributed to the recently published Intergovernmental Panel on Climate Change report, and Nathan Myhrvold, the founder and CEO of a technology corporation, Intellectual Ventures LLC. It is the third paper on which they have collaborated. (more…)

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Climate Change is not an All-or-Nothing Proposition, Researcher Says

BOSTON — An Ohio State University statistician says that the natural human difficulty with grasping probabilities is preventing Americans from dealing with climate change.

In a panel discussion at the American Association for the Advancement of Science meeting on Feb. 15, Mark Berliner said that an aversion to statistical thinking and probability is a significant reason that we haven’t enacted strategies to deal with climate change right now. (more…)

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UMass Amherst Climate Model is First to Study Climate Effects of Arctic Hurricanes

AMHERST, Mass. – Though it seems like an oxymoron, Arctic hurricanes happen, complete with a central “eye,” extreme low barometric pressure and towering 30-foot waves that can sink small ships and coat metal platforms with thick ice, threatening oil and gas exploration. Now climate scientists at the University of Massachusetts Amherst and in England report the first conclusive evidence that Arctic hurricanes, also known as polar lows, play a significant role in driving ocean water circulation and climate.

Results point to potentially cooler conditions in Europe and North America in the 21st century than other models predict. (more…)

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Sea Floor Samples Help Explain Arid Southwest

Surface-dwelling algae adjust their biochemistry to surface temperatures. As they die and sink to the bottom, they build a sedimentary record of sea-surface temperature across millennia. Brown’s work on surface temperatures, coupled with work from Texas A&M on rainfall and weather patterns, has helped chart the wetter, lake-filled geological history of the currently arid American West.

During the last ice age, the landscape of the American West was very different. Where now there are deserts and salt flats in the Southwest and Great Basin regions, there once were giant lakes and wetlands. The Great Salt Lake, for example, is a tiny remnant of the prehistoric Lake Bonneville, which at one time covered almost 20,000 square miles. (more…)

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Shrinking Snow Depth on Arctic Sea Ice Threatens Ringed Seal Habitat

As sea ice in the Arctic continues to shrink during this century, more than two thirds of the area with sufficient snow cover for ringed seals to reproduce also will disappear, challenging their survival, scientists report in a new study.

The ringed seal, currently under consideration for threatened species listing, builds caves to rear its young in snow drifts on sea ice. Snow depths must be on average at least 20 centimeters, or 8 inches, to enable drifts deep enough to support the caves. (more…)

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