"Aircraft condensation trails criss-crossing the sky may be warming the planet on a normal day more than the carbon dioxide emitted by all planes since the Wright Brothers' first flight in 1903, a study said on Tuesday."

"President Barack Obama on Wednesday proposed to cut U.S. oil imports by a third over 10 years, a goal that eluded his predecessors and seen as extremely ambitious by analysts skeptical it can succeed."

"Giving new meaning to toasted wheat, a team of agricultural researchers has spent the past three years and almost a million dollars installing electric heaters over wheat fields in the desert of Maricopa, Ariz."

"Vegetation change underway in northern forests as a result of climate change creates feedback loop that prompts more warming, scientists say."

"The American Lung Association has opened a billboard campaign against Fred Upton, the Republican chairman of the House Commerce and Energy Committee, taking him to task for his legislative attacks on the Environmental Protection Agency and clean air regulations."

"Senate Democrats hope to siphon votes from a GOP bid to hamstring EPA climate rules by voting first on a Democratic alternative."
 

"The U.S. Environmental Protection Agency has agreed to grant a petition by three nonprofit organizations to withdraw its approval for the potent greenhouse gas HFC-134a to be used in new automobile air conditioning systems."

"Spawned by strangely cold temperatures, 'beautiful' clouds helped strip the Arctic atmosphere of most of its protective ozone this winter, new research shows."

"In a setback that could stall the rollout of California's landmark climate change law, a court in San Francisco has ruled that the state must spend more time studying alternatives to the measure's key feature -- a cap-and-trade program on greenhouse gas emissions -- before it goes into effect Jan. 1."

"The legislation is approved in a largely party-line vote. It's unlikely to win much support in the Democratic-ruled Senate."