"A dispute between Canadian pipeline giant Enbridge Inc. and a small Colorado operator is flaring into a political showdown over whether U.S. domestic production will be squeezed out by oil sands crude flowing from across the northern border."

"WASHINGTON -- Taking aim at California's pioneering efforts to bolster animal safety, the House Agriculture Committee has moved to block states from imposing their own standards for agriculture products on producers from other states."

"Despite promises from the nuclear industry to regulators and consumers that they learned from mistakes of the past, the nation's first two nuclear reactor projects built from scratch in 30 years are headed toward hundreds of millions of dollars in cost overruns and months, if not years, of delays."

"Senior environment officials from the United States, Mexico and Canada meeting in New Orleans on Wednesday were briefed on environmental concerns facing homeland communities, including indoor air pollution in Alaska, protecting freshwater sources from sewage and other pollutants in Mexico, and the impact of climate change already on First Nation villages along the Arctic Circle."

A Colorado family typifies a growing number of Americans whose health may be put at risk by the drift of pesticides from their neighbors' fogging activities. But neighbors doing the fogging say they, too, are acting to protect their health. A judge ruled this month that pesticide drift can be a form of trespass.

"Evidence showing that cap and trade can bolster a new revenue stream has some state and federal officials quietly seeking answers."

"A conservative group that has used public records requests in an attempt to publicize emails written by climate scientists has turned its attention to reporters who cover the environment."

"OTTAWA -- Several hundred Canadian scientists and their supporters held an unprecedented protest march on Tuesday to demonstrate against the government's decision to close down major facilities and fire research staff."

"STUART, Neb. -- Stepping carefully through a 12-foot-deep canyon gouged into the sandy soil of their family ranch by a long-gone storm, Kurt and Laura Meusch ask a Shakespearean question: What's in a name?"

"The first signs of bipartisan support for overhauling the nation's chemical safety law emerged Monday, as three Republicans joined 23 other senators calling for tough restrictions on toxic flame retardants."