"GENEVA -- Mercury pollution in the top layer of the world's oceans has doubled in the past century, part of a man-made problem that will require international cooperation to fix, the U.N.'s environment agency said Thursday."

"Drawing on growing output from the Bakken and Eagle Ford shale plays, U.S. crude production averaged 6.4 million barrels a day last year, a gain of 800,000 barrels daily over 2011 -- the largest annual increase since the birth of the U.S. oil industry in 1859, the Energy Information Administration said yesterday."

"RALEIGH -- Conservation groups filed a lawsuit on Tuesday against the state Environmental Management Commission, Duke Energy and Progress Energy seeking the cleanup or shut-down of 14 ash pits that collect tons of waste from coal-burning power plants across the state."

"ANCHORAGE -- As response teams continued Tuesday to evaluate Royal Dutch Shell's once-grounded oil drilling rig, the Coast Guard, the Obama administration and U.S. Sen. Mark Begich all announced investigations or reviews taking a close look at Shell":

"Oil-sands development is polluting nearby remote Alberta lakes with rising levels of a toxic carcinogen, refuting long-standing claims that waterway pollution in the region is largely naturally occurring, a study has found."

"Tug boats tow 28-tonne Kulluk to nearby Kiliuda Bay where the damage can be assessed after grounding on Alaskan coast."

"DETROIT -- A U.S. government safety agency wants electric and hybrid vehicles to make more noise when traveling at low speeds so pedestrians can hear them coming."