*First such levels measured outside polar regions*
In Hebrew, the Dead Sea is called Yam ha-Melah, the “sea of salt.” Now measurements show that the sea’s salt has profound effects on the chemistry of the air above its surface.
The atmosphere over the Dead Sea, researchers have found, is laden with oxidized mercury. Some of the highest levels of oxidized mercury ever observed outside the polar regions exist there. (more…)
Lake Tahoe, seen here from Emerald Bay, was one of the primary validation sites for the global lake study. The lake, which straddles the borders of California and Nevada, is the largest alpine lake in North America. Image credit: NASA-JPL
WASHINGTON – In the first comprehensive global survey of temperature trends in major lakes, researchers have determined that Earth’s largest lakes have warmed during the past 25 years in response to climate change.
Philipp Schneider and Simon Hook of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., used satellite data to measure the surface temperatures of 167 large lakes worldwide.
They reported an average warming rate of 0.45 degrees Celsius (0.81 degrees Fahrenheit) per decade, with some lakes warming as much as 1 degree Celsius (1.8 degrees Fahrenheit) per decade. The warming trend was global, and the greatest increases were in the mid- to high-latitudes of the Northern Hemisphere. (more…)
Current state-of-the-art global climate models predict substantial warming in response to increases in greenhouse gases such as carbon dioxide. The models, though, disagree widely in the magnitude of the warming we can expect. The disagreement among models is mainly due to the different representation of clouds. Some models predict that global mean cloud cover will increase in a warmer climate and the increased reflection of solar radiation will limit the predicted global warming. Other models predict reduced cloudiness and magnified warming. (more…)
*Climate change will force them south, where they are unsuited for the diet*
A polar bear breaks through thin Arctic Ocean ice Aug. 23, 2009. Image credit: Canadian Coast Guard/USGS
Will polar bears survive in a warmer world? UCLA life scientists present new evidence that their numbers are likely to dwindle.
As polar bears lose habitat due to global warming, these biologists say, they will be forced southward in search of alternative sources of food, where they will increasingly come into competition with grizzly bears.
To test how this competition might unfold, the UCLA biologists constructed three-dimensional computer models of the skulls of polar bears and grizzly bears — a subspecies of brown bears — and simulated the process of biting. The models enabled them to compare the two species in terms of how hard they can bite and how strong their skulls are. (more…)
Rotating corn with shrubby legumes holds a key for fueling Africa’s green revolution. Image credit: Michigan State University
EAST LANSING, Mich. — Crop diversification with shrubby legumes mixed with soybean and peanuts could be the key to sustaining the green revolution in Africa, according to a Michigan State University study.
The study, which appears in the Nov. 22 issue of the Proceedings of the National Academy of Sciences, states that diversifying crops would boost production of nutrient-enriched grain by 12 percent to 23 percent, said Sieglinde Snapp, a crop and soil scientist at Michigan State University’s Kellogg Biological Station who led the study. (more…)
ANN ARBOR, Mich.— In an effort to understand how fast sea level could rise as the climate warms, a University of Michigan researcher has developed a new theory to describe how icebergs detach from ice sheets and glaciers. (more…)
*Significant Deposits Found in 14 States*
Rare Earth Elements. Image credit: USGS
Approximately 13 million metric tons of rare earth elements (REE) exist within known deposits in the United States, according to the first-ever nationwide estimate of these elements by the U.S. Geological Survey.
This estimate of domestic rare earth deposits is part of a larger report that includes a review of global sources for REE, information on known deposits that might provide domestic sources of REE in the future, and geologic information crucial for studies of the availability of REE to U.S. industry.
The report describes significant deposits of REE in 14 states, with the largest known REE deposits at Mountain Pass, Calif.; Bokan Mountain, Alaska; and the Bear Lodge Mountains, Wyo. The Mountain Pass mine produced REE until it closed in 2002. Additional states with known REE deposits include Colorado, Florida, Georgia, Idaho, Illinois, Missouri, Nebraska, New Mexico, New York, North Carolina, and South Carolina. (more…)
The steamiest places on the planet are getting warmer. Conservative estimates suggest that tropical areas can expect temperature increases of 3 degrees Celsius by the end of this century. Does global warming spell doom for rainforests? Maybe not. Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute, and colleagues report in the journal Science that nearly 60 million years ago rainforests prospered at temperatures that were 3-5 degrees higher and at atmospheric carbon dioxide levels 2.5 times today’s levels.
About the image: This is a scanning electron microscopy image of characteristic angiosperm pollen taxa from the Paleocene-Eocene Thermal Maximum. Image credit: Francy Carvajal, Smithsonian Tropical Research Institute (more…)
