"Chinese authorities have told pilots who fly to Beijing they must be qualified to land their aircraft in the low visibility bought about by smog -- the latest missive related to the capital's heavy air pollution, which the government this week lauded as a beneficial shield against missile attacks."

"The hole in the ozone layer is stabilizing but will take until about 2070 to fully recover, according to new research by NASA scientists."

"Commentaries by two of China's most influential news outlets suggesting that the country's air pollution crisis was not without a silver lining drew a withering reaction on Tuesday from internet users and other media."

"Hundreds of thousands of children still at risk from dangerous levels of air pollution as poisonous smog fills cities, study says"

"The U.S. environmental regulator argued in court on Tuesday that its rule limiting mercury and hazardous air pollutants is 'appropriate and necessary,' not an improper interpretation of the federal Clean Air Act as industry groups and some states contend."

"WASHINGTON -- U.S. Supreme Court justices offered President Barack Obama's administration some encouragement on Tuesday as they weighed the lawfulness of a federal regulation limiting air pollution that crosses state lines, mostly emissions from coal-fired power plants."

"Governor Christie has refused to join a coalition of eight Eastern states seeking to curb air pollution blowing in from Midwest and Southern coal-fired power plants that help make New Jersey’s air quality among the worst in the nation."

"WASHINGTON — In a battle that pits the East Coast against the Midwest over the winds that carry dirty air from coal plants, the governors of eight Northeastern states plan to petition the Environmental Protection Agency on Monday to force tighter air pollution regulations on nine Rust Belt and Appalachian states."

"The United States will help China implement stricter emission standards for vehicles in a bid to help the world's biggest carbon emitter tackle rampant air pollution, the White House announced on Thursday."

"Environmental and industry advocates say a proposed air emissions reporting permit issued last week for BHP Billiton Ltd.'s San Juan Coal Mine in northwestern New Mexico is the first -- or among the first -- ever proposed for a coal mine."