"Northrop Grumman Corp on Thursday reached a settlement with U.S. environmental regulators that requires the aerospace giant to spend about $21 million to clean up groundwater pollution dating from World War II manufacturing through the 1980s."

"Bouts of extreme muggy heat lasting for days, once rare in California, are becoming more frequent and intense due to ocean patterns altered by climate change, scientists said in a study released on Tuesday."

"A $774 billion plan to power Europe with Sahara sunlight is gaining momentum, even as critics see high risks in a large corporate project using young technology in north African countries with weak rule of law."

"Evolution takes place over long stretches of time: millennia and epochs. But some new research shows that animals might be changing much faster than nearly anyone thought. ... Those changes ... seem to be linked to humans."

"The Nuclear Regulatory Commission ... is urging nuclear plants to embrace a more systematic approach to assessing fire risk -- one that relies on a computer program."

Tidelands in Skagit County are being flooded to help restore the estuary.

"How much longer will the 'Oil Age' last?"

"Government scientists who study the depletion of Earth’s protective ozone layer are pointing to a previously unheralded culprit: nitrous oxide."

"Fire crews were battling to save hundreds of homes that were threatened by two wildfires burning in dry, explosive brush near La Cañada Flintridge and on the Palos Verdes Peninsula."

The Justice Department and Illinois are suing Midwest Generation, charging the utility company with evading the Clean Air Act by not installing pollution controls when modernizing its plants. The move marks an Obama administration reversal of Bush policies.