For the first time ever, the EPA and the Department of Transportation undertake to set emission standards for medium- and heavy-duty trucks. Such trucks now average six miles per gallon-the same as they did 40 years ago.
Poachers in Vietnam kill one of seven Javan rhinos in the country for its horn. Only about 60 remain worldwide.
The Supreme Court lifts a ban on Monsanto's genetically modified alfalfa, ruling that a lower court "abused its discretion" by requiring a full study of the pesticide-resistant seeds' environmental impact.
Widespread use of crops genetically modified to tolerate Monsanto's weed killer Roundup has led to the burgeoning of Roundup- resistant "superweeds."
The EPA bans endosulfan, a highly toxic, bioaccumulative insecticide linked to autism, birth defects, and delayed puberty. Already outlawed in more than 60 countries, endosulfan is still widely produced and used in India and China.
The Sunday Times of London retracts key claims in its "Climategate" story, which suggested that climate scientists at the University of East Anglia and elsewhere were falsifying global-warming data.
Two feet of rain falls in six hours in Guangdong, China, a 500-year record.
In Nashville, Tennessee, 13.5 inches of rain falls over two days, a 1,000-year record.
An Inuit hunter kills a "grolar bear," the second confirmed encounter with a grizzly-polar bear hybrid. As the Arctic warms, grizzlies are moving into polar bear territory.
Senator Lisa Murkowski (R-Alaska) leads an effort to strip the EPA of the authority to limit emissions of carbon dioxide and other greenhouse gases. The measure is defeated 53 to 47, with all Republican senators and six Democrats voting in favor.
A move to raise the liability cap for offshore-oil-drilling accidents from $75 million to $10 billion is blocked by Senator James Inhofe (R-Okla.), who argues that drilling should not be limited to companies large enough to afford the higher Figure.
The journal Biology Letters reports that since 1998, snake populations around the world have gone into a steep decline, some by as much as 90 percent.
The National Oceanic and Atmospheric Administration declares that stocks of swordfish and three other species have been fully rebuilt and are no longer being overfished.
Interior secretary Ken Salazar approves Cape Wind, the nation's first offshore wind farm, for the waters off Cape Cod.
"The world's largest conservation agreement" protects Canada's boreal forest, an area larger than France.
A proposed deal by the International Whaling Commission to sanction limited commercial whaling by Japan, Norway, and Iceland for 10 years falls apart, leaving the future of whale conservation in doubt. —Paul Rauber
Left column, from top: iStockphoto/jondpatton, iStockphoto/Antagain, iStockphoto/appleuzr
Right column, from top: iStockphoto/GeorgeClerk, iStockphoto/GlobalP