Humans pump thousands of tons of vapor from the metallic element mercury into the atmosphere each year, and it can remain suspended for long periods before being changed into a form that is easily removed from the atmosphere.
New research shows that the upper troposphere and lower stratosphere work to transform elemental mercury into oxidized mercury, which can easily be deposited into aquatic ecosystems and ultimately enter the food chain. (more…)
Dust avalanches around impact craters on Mars appear to be the result of the shock wave preceding the actual impact, according to a study led by an undergraduate student at the UA.
When a meteorite careens toward the dusty surface of the Red Planet, it kicks up dust and can cause avalanching even before the rock from outer space hits the ground, a research team led by an undergraduate student at the University of Arizona has discovered.
“We expected that some of the streaks of dust that we see on slopes are caused by seismic shaking during impact,” said Kaylan Burleigh, who led the research project. “We were surprised to find that it rather looks like shockwaves in the air trigger the avalanches even before the impact.” (more…)
ANN ARBOR, Mich.— For the first time, the chemical “fingerprints” of the element mercury have been used by University of Michigan researchers to directly link environmental pollution to a specific coal-burning power plant.
The primary source of mercury pollution in the atmosphere is coal combustion. The U-M mercury-fingerprinting technique – which has been under development for a decade – provides a tool that will enable researchers to identify specific sources of mercury pollution and determine how much of it is being deposited locally. (more…)
J. Timmons Roberts, professor of sociology and director of the Center for Environmental Studies, led a group of Brown researchers and students to the United Nations climate change negotiations in Durban, South Africa. On his return, Roberts spoke with Richard Lewis, reflecting on the Durban meetings, the status of research, and the challenges of activism on issues of climate change.
Timmons Roberts, professor and director of the Center for Environmental Studies, has just returned from attending climate talks in Durban, South Africa. Roberts and a delegation from Brown — faculty, postdoctoral researchers, graduate and undergraduate students — witnessed the negotiations up close as observers to ministerial speeches and negotiations. The talks ended with an agreement to extend the greenhouse gas emissions targets set under the Kyoto Protocol and a pledge to work on a replacement treaty incorporating the United States, China, and India.
Roberts spoke with Richard Lewis on the importance of the talks, the need for industrialized countries to compensate developing countries for damages from climate change, and the unique opportunity for people from Brown’s environmental program to attend the talks. (more…)
A Yale University-led research team has found evidence that carbon dioxide levels in Earth’s atmosphere plunged prior to and during the initial icing of Antarctica, about 34 million years ago. The new findings provide further evidence of atmospheric carbon dioxide’s role as a major trigger of global climate change.
“CO2 is tracking global cooling at that time,” said Yale geochemist Mark Pagani, lead author of a paper published online Dec. 1 in the journal Science. “It’s important to demonstrate that there are obvious linkages between CO2 and climate change. It’s one more piece of evidence that CO2 is a primary lever on climate.” (more…)
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…)
PASADENA, Calif. — Data from a NASA planetary mission have provided scientists evidence of what appears to be a body of liquid water, equal in volume to the North American Great Lakes, beneath the icy surface of Jupiter’s moon, Europa.
The data suggest there is significant exchange between Europa’s icy shell and the ocean beneath. This information could bolster arguments that Europa’s global subsurface ocean represents a potential habitat for life elsewhere in our solar system. The findings are published in the scientific journal Nature.(more…)
*Evidence of water mass moving south 70 million years ago shows how warmth was distributed*
COLUMBIA, Mo. – New research from the University of Missouri indicates that Atlantic Ocean temperatures during the greenhouse climate of the Late Cretaceous Epoch were influenced by circulation in the deep ocean. These changes in circulation patterns 70 million years ago could help scientists understand the consequences of modern increases in greenhouse gases.
“We are examining ocean conditions from several past greenhouse climate intervals so that we can understand better the interactions among the atmosphere, the oceans, the biosphere, and climate,” said Kenneth MacLeod, professor of geological sciences in the College of Arts and Science. “The Late Cretaceous Epoch is a textbook example of a greenhouse climate on earth, and we have evidence that a northern water mass expanded southwards while the climate was cooling. At the same time, a warm, salty water mass that had been present throughout the greenhouse interval disappeared from the tropical Atlantic.” (more…)
