"About 180 nations met for U.N. climate talks on Monday amid warnings that time was running out for them to reach agreement on a hugely complex pact, due for completion at the end of the year."

"There might be a scientific reason that the old-growth trees in Yosemite National Park don't seem quite as big or as plentiful as those in your grandfather's early snapshots of the park."

"The changing global climate will pose profound strategic challenges to the united states in coming decades, raising the prospect of military intervention to deal with the effects of violent storms, drought, mass migration and pandemics, military and intelligence analysts say."

"Three major glaciers in Alaska and Washington state have thinned and shrunk dramatically, clear signs of a warming climate, according to a study released Thursday by the U.S. Geological Survey."

EPA Administrator Lisa P. Jackson said the agency will look at new evidence in reconsidering the Bush-administration decision not to regulate perchlorate in drinking water.

"Psychological barriers like uncertainty, mistrust and denial keep most Americans from acting to fight climate change, a task force of the American Psychological Association said on Wednesday."

"In a matter of years or decades, researchers believe, animals and plants already are adapting to life in a warmer world. Some species will be unable to change quickly enough and will go extinct, but others will evolve, as natural selection enables them to carry on in an altered environment."

"Mexico aims to put a detailed offer to cut the growth of its own greenhouse gas emissions on the negotiating table at global climate change talks in Copenhagen this year, a senior environmental policymaker said."

"With the fight over health care reform absorbing all the bandwidth on Capitol Hill, Democrats fear a major climate change bill may be left on the cutting-room floor this year."