"KANSAS CITY, Mo. -- A federal agency says TransCanada Corp. has temporarily shut down its existing Keystone pipeline after tests showed 'possible safety issues.'"

"After a hot spring and a scorching summer, this winter is likely to continue a U.S. warming trend that could make 2012 the hottest year since modern record-keeping began, U.S. weather experts said Thursday."

"Job growth is one of the most important issues of the 2012 election, and a recent report suggests that continued investment in green jobs could be a boon to the U.S. economy."

"Climate change contributed to a fivefold increase in weather-related natural disasters in North America over the past three decades, according to Munich Re, the world’s biggest reinsurer."

"As the wind industry clamors to renew a key tax credit (again), industry leaders explore how to break free from the boom-bust cycle the subsidy has them trapped in."

"ANCHORAGE, Alaska — For hundreds, perhaps thousands, of years, Natives of Southeast Alaska have paid artisans to create tools, clothing and ceremonial regalia adorned with feathers."

"Federal appeals court judges appeared skeptical today about U.S. EPA's argument that it is required under the Clean Air Act to use a less stringent implementation regime for fine particulates than it is for more coarse -- and less dangerous -- particles."

"Carbon dioxide has been vilified for decades as a driver of global warming. A new study finds signs that CO2, exhaled in every breath, can exert an equally worrisome threat -- impaired cognition -- in nearly every energy-efficient classroom, meeting hall or office space."

"Honeywell International Inc said Tuesday it could take nine to 12 months to upgrade the Metropolis Works uranium conversion facility in Southern Illinois to ensure it could withstand a strong earthquake or tornados."

"With all of the theatrics of a town hall-style presidential debate [Tuesday] night, President Obama and Republican challenger Mitt Romney sparred over who is the bigger 'Mr. Oil' and 'Mr. Gas' amid declining U.S. energy imports and rising domestic production."