"Engineering experts probing the Gulf of Mexico oil spill exposed holes in BP's internal investigation as the company was questioned Sunday for the first time in public about its findings."

"Climate ministers and top negotiators from dozens of nations remain deadlocked over how to cut greenhouse gases less than three months before the next major international climate summit."

"The Obama administration is renewing the long-running effort to win U.S. ratification of two international treaties aimed at limiting the reach of the world's most toxic chemicals."

"The tension between drillers in Pennsylvania's gas-rich Marcellus shale and communities trying protect natural resources has reached a fevered pitch in Clinton County, where a zoning hearing board resigned rather than allow a water withdrawal station at a scenic bend of the West Branch of the Susquehanna River that draws kayakers, hang gliders, hunters and fly fishermen."

For years, mine safety experts urged the Mine Safety and Health Administration to require coal-dust monitors in mines. Mining companies and MSHA resisted. Now Massey Energy Co. is using the lack of such monitors as an argument to deny charges that it did not do enough to control the buildup of explosive coal dust at its Upper Big Branch Mine, where 29 workers died in a massive blast on April 5.

"An activist with the Communities for a Better Environment takes on Big Oil over delaying the state's global warming law."

"Federal officials began a sweeping crackdown on pollution in the Chesapeake Bay on Friday - threatening to punish five mid-Atlantic states with rules that could raise sewer bills and put new conditions on construction."