Category Archives: Environment

Threading the Climate Needle: The Agulhas Current System

*Increased Agulhas “leakage” significant player in global climate variability*

The Agulhas Current which runs along the east coast of Africa may not be as well known as its counterpart in the Atlantic, the Gulf Stream. But now researchers are taking a closer look at this current and its “leakage” from the Indian Ocean into the Atlantic Ocean–and what that may mean for climate change.

In results of a study published in this week’s issue of the journal Nature, a team of scientists led by University of Miami Rosenstiel School of Marine & Atmospheric Science Oceanographer Lisa Beal, suggests that Agulhas leakage could be a significant player in global climate variability. (more…)

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Melting Ice on Arctic Islands a Major Player in Sea Level Rise

ANN ARBOR, Mich.— Melting glaciers and ice caps on Canadian Arctic islands play a much greater role in sea level rise than scientists previously thought, according to a new study led by a University of Michigan researcher.

The 550,000-square-mile Canadian Arctic Archipelago contains some 30,000 islands. Between 2004 and 2009, the region lost the equivalent of three-quarters of the water in Lake Erie, the study found. Warmer-than-usual temperatures in those years caused a rapid increase in the melting of glacier ice and snow, said Alex Gardner, a research fellow in the Department of Atmospheric, Oceanic and Space Sciences who led the project. The study is published online in Nature on April 20. (more…)

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Invasive Mussels Causing Massive Ecological Changes in Great Lakes

ANN ARBOR, Mich. — The ongoing spread of non-native mussels in the Great Lakes has caused “massive, ecosystem-wide changes” throughout lakes Michigan and Huron, two of the planet’s largest freshwater lakes, according to a new University of Michigan-led study.

The blitzkrieg advance of two closely related species of mussels—the zebra and quagga—is stripping the lakes of their life-supporting algae, resulting in a remarkable ecological transformation and threatening the multibillion-dollar U.S. commercial and recreational Great Lakes fisheries. (more…)

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Ancient Fossils Hold Clues for Predicting Future Climate Change, Scientists Report

By studying fossilized mollusks from some 3.5 million years ago, UCLA geoscientists and colleagues have been able to construct an ancient climate record that holds clues about the long-term effects of Earth’s current levels of atmospheric carbon dioxide, a key contributor to global climate change. 

Two novel geochemical techniques used to determine the temperature at which the mollusk shells were formed suggest that summertime Arctic temperatures during the early Pliocene epoch (3.5 million to 4 million years ago) may have been a staggering 18 to 28 degrees Fahrenheit warmer than today. And these ancient fossils, harvested from deep within the Arctic Circle, may have once lived in an environment in which the polar ice cap melted completely during the summer months.  (more…)

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Climate Change From Black Carbon Depends on Altitude

Palo Alto, CA — Scientists have known for decades that black carbon aerosols add to global warming. These airborne particles made of sooty carbon are believed to be among the largest man-made contributors to global warming because they absorb solar radiation and heat the atmosphere. New research from Carnegie’s Long Cao and Ken Caldeira, along with colleagues George Ban-Weiss and Govindasamy Bala, quantifies how black carbon’s impact on climate depends on its altitude in the atmosphere. Their work, published online by the journal Climate Dynamics, could have important implications for combating global climate change. (more…)

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Japanese Officials Unveil Important Information They Concealed For a Month

Japanese officials struggled through the day on Tuesday to explain why it had taken them a month to disclose large-scale releases of radioactive material in mid-March at a crippled nuclear power plant, as the government and an electric utility disagreed on the extent of continuing problems there.

The government announced Tuesday morning that it had raised its rating of the severity of the accident at the Fukushima Daiichi Nuclear Power Station to 7, the worst on an international scale, from 5. Officials said that the reactor had released one-tenth as much radioactive material as the Chernobyl accident in 1986, but still qualified as a 7 according to a complex formula devised by the International Atomic Energy Agency, according to New York Times. (more…)

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