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 Stationwho led the study.
Malawi has been called the cradle of Africa’s green revolution. Through its government subsidizing 90 percent of fertilizer and superior corn seed costs, Malawi has reaped substantial gains in productivity of calorie-rich food. The successful program has had some unintended consequences, though, such as reliance on starchy cereals, expensive fertilizer and depleted soils. (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.
This process of “iceberg calving” isn’t well understood. While scientists believe it currently accounts for roughly half of the mass lost in shrinking ice sheets, current sea level rise models don’t take changes in iceberg calving into account in their predictions, says Jeremy Bassis, an assistant professor in the Department of Atmospheric, Oceanic and Space Sciences. (more…)
Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the rescue project is the first to successfully breed this species. Image credit: Brian Gratwice, Smithsonian's National Zoo
As frogs around the world continue to disappear—many killed by a rapidly spreading disease called chytridiomycosis, which attacks the skin cells of amphibians—one critically endangered species has received an encouraging boost. Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the Panama Amphibian Rescue and Conservation Project is the first to successfully breed this species.
“We are some of the first researchers to attempt to breed these animals into captivity and we have very little information about how to care for them,” said Brian Gratwicke, international coordinator for the project and a research biologist at the Smithsonian’s National Zoo, one of nine project partners. “We were warned that we might not be able to keep these frogs alive, but through a little bit of guesswork, attention to detail and collaboration with other husbandry experts—we’ve managed to breed them. The lessons we’re learning have put us on target to save this incredible species and our other priority species in Panama.”(more…)
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…)
The Earth is constantly manufacturing new crust, spewing molten magma up along undersea ridges at the boundaries of tectonic plates. The process is critical to the planet’s metabolism, including the cycle of underwater life and the delicate balance of carbon in the ocean and atmosphere.
Now, scientists at the Woods Hole Oceanographic Institution (WHOI) have observed ocean crust forming in an entirely unexpected way—one that may influence those cycles of life and carbon and, in turn, affect the much-discussed future of the world’s climate.
Working at the Guaymas basin in the Gulf of California, WHOI scientists confirmed what they suspected from brief glimpses of the area during previous missions: The inner Earth is injecting swaths of magma called sills as far as 50 kilometers away from the plate boundary, on each side of the ridge —nearly 10 times farther from such an active ocean ridge than had been observed before.(more…)
