END OF FIN: Hammerheads, great whites and 18 other sharks are on the brink of extinction — four more species than a year ago — and overfishing is a main cause, according to a new report by the International Union for the Conservation of Nature. Sharks are especially vulnerable to overfishing because they take several years to mature and produce relatively few offspring, yet the ancient predators are "virtually unprotected" in the open ocean, the researchers say. The practice of "finning" — chopping off sharks' fins for a popular Asian soup and discarding their bodies — is particularly devastating for hammerhead sharks, with one type declining by 99 percent in the past 30 years. The northwest Atlantic Ocean only has about half as many sharks now as it did in the early 1970s, according to the report, and more than 30 percent of all open-ocean sharks around the world are in danger of going extinct. (Sources: Bloomberg News, Guardian, BBC News, Agence France-PresseNew Scientist)

SLITHER HITHER: Mark Sanford isn't the only unpopular snake in South Carolina this week. Seven Burmese pythons are still settling into their new home at the Savannah River Ecology Lab in Aiken, part of a research project aimed at figuring out whether the invasive species might spread north from the Florida Everglades. The giant constricting serpents began showing up throughout the South Florida swamp in 1992, possibly freed from pet shops that were destroyed by Hurricane Andrew. They went on to thrive in the Everglades, competing with (and sometimes eating) American alligators, and are now reproducing in the wild. After a recent study showed that the U.S. South mimics the pythons' native Southeast Asian habitat, several scientists devised this experiment to find out how well the animals can survive South Carolina's cooler climate. (Source: Associated Press)

WARMING UP TO THE IDEA: Three-quarters of Americans want the federal government to regulate greenhouse gas emissions, according to a new Washington Post-ABC News poll, with support crossing major party lines. While the poll also showed that only 52 percent are in favor of a cap-and-trade approach — down slightly from last July — the House climate bill proposing such an approach continues to gather support ahead of tomorrow's expected vote. That support comes largely from concessions the bill's authors have made to a variety of industries, including nuclear, ethanol and rural electric power, in recent days. There's still plenty of opposition among Republicans and in coal-heavy states like West Virginia, however, and even some advocates of cutting emissions — such as filmmaker Todd Darling, who wrote an op-ed in today's LA Times — would still prefer a carbon tax to cap-and-trade. (Sources: Washington Post, ABC News, AP, Charleston Daily Mail, Los Angeles Times)

TRUST THE GUST: Although wind power is the fastest-growing source of American electricity, it still makes up less than 3 percent of the country's electric pie, and probably won't change soon even at present growth rates. Yet despite naysayers who harp on the fickle nature of wind, a new study that calculates global wind-power potential in unprecedented detail reports some encouraging news. By tapping the right sources — namely offshore — current technology could capture enough wind to supply 40 times the world's current electricity consumption. In the U.S. Midwest alone, wind gusts are strong enough to provide up to 16 times the current U.S. demand for electricity. The problem, however, remains figuring out a way to get all that untapped power from remote, wind-swept areas to faraway urban centers. (Source: TIME

TOWER OF LESS POWER: The Western Hemisphere's tallest building can stand a little taller soon, knowing it has one of the smallest carbon footprints of any 1,451-foot-tall giant. Chicago's Sears Tower will undergo a five-year, $350 million green upgrade, building officials announced Wednesday, including plans to install wind turbines, solar panels and gardens on its staggered rooftops. The measures are expected to cut the iconic skyscraper's energy use by 80 percent and its water use by 24 million gallons a year. Set to be renamed the Willis Tower later this summer, the 110-story building is also seeking LEED certification. (Sources: New York Times, AP)

Russell McLendon

(Photo: John Bazemore/AP)

The opinions expressed by MNN Bloggers and those providing comments are theirs alone, and do not reflect the opinions of MNN.com. While we have reviewed their content to make sure it complies with our Terms and Conditions, MNN is not responsible for the accuracy of any of their information.