"The Obama administration is considering cutting greenhouse-gas emissions from power plants by reaching beyond the plants themselves -- an unusual approach that could run afoul of anti-pollution laws."

"Smog could worsen across the United States in the coming decades as climate change boosts summer temperatures and makes ozone levels more difficult to control, a new study says."

"A draft letter from a U.S. EPA science advisory committee recommends a tight standard for how much ozone pollution can be in the air, recommending that the lower bound of the standard should be 60 parts per billion, much lower than the current standard. But the letter notes that committee members haven't made a decision on the upper bound of the ozone standard."

"The Obama administration on Friday scored its third major legal victory on air pollution in less than month when a federal appeals court rejected an industry challenge to its latest health standards for fine particulate matter, or soot."

"The World Health Organization says air pollution in many of the world's cities is breaching its guidelines. Its survey of 1,600 cities in 91 countries revealed that nearly 90% of people in urban centres breathe air that fails to meet levels deemed safe."

"Scientists have made a surprising discovery about ethanol: The more it was used by drivers in Sao Paulo, Brazil, the more ozone they measured in the local environment."

"Almost 150 million people live in areas where air pollution levels are unhealthy to breathe, an increase from a previous American Lung Association report."

"In a major victory for the Obama administration, the Supreme Court on Tuesday upheld the authority of the Environmental Protection Agency to regulate the smog from coal plants that drifts across state lines from 28 Midwestern and Appalachian states to the East Coast."