"BALTIMORE, Md. -- Gov. Martin O'Malley has interceded with the U.S. Environmental Protection Agency on behalf of Carnival Cruise Lines after the company threatened to pull its business from Baltimore over a pending air-quality regulation that would require large, ocean-going ships to burn cleaner fuel."

"HONG KONG -- China’s cabinet has adopted 10 measures to improve air quality in the latest move aimed at responding to the dense smog that has repeatedly enveloped Beijing and other major Chinese cities in recent years."

"GE Energy Services' coal-fired power plant in Homer City will be required to meet federal standards for emissions of sulfur dioxide that are more protective of human health."

"The Houston area produces about a quarter of the nation's gasoline, and about a third of the plastics that are in our cars, cupboards and just about everywhere else. So it is no surprise that this heavily industrial area has a problem with air pollution. But in the past decade, Houston's air has improved dramatically."

"Federal judges [Tuesday] rejected challenges from both industry and environmental groups to U.S. EPA's air standards for lead smelters."

"Denise Mauzerall arrived in Beijing this year at a time that was both horrifying and illuminating. The capital was facing some of its worst pollution in recent memory and Mauzerall, a Princeton environmental engineering professor, was passing through on her way to a university forum on the future of cities."

"The fate of many coal-fired power plants may rest on how boldly Obama tries to fulfill his pledge to cut greenhouse gas emissions."

"Methane emissions from coal mines escaped being curbed by the Environmental Protection Agency, which said mandatory U.S. budget cuts didn't leave it with the resources to determine if the pollution is a significant risk."

"A little-noticed change in U.S. EPA air policy has turned a national pollution-monitoring network that has been providing data to researchers for 22 years into a regulatory tool, leaving states scrambling to figure out the implications."

"More than 50,000 high-polluting diesel engines have been cleaned up or removed from U.S. roads in a federal program designed to reduce smog and greenhouse gases, according to a new Environmental Protection Agency report to Congress. While industry and environmental officials call the program a landmark success, it is now threatened with a 70 percent cut in funding under the Obama Administration’s new budget."

"On the brink of federal regulatory review, chemicals in deodorants, lotions and conditioners are showing up in Chicago’s air at levels that scientists call alarming. The airborne compounds – cyclic siloxanes – are traveling to places as far as the Arctic, and can be toxic to aquatic life. “These chemicals are just everywhere,” said Keri Hornbuckle, an engineering professor at the University of Iowa. "

"Scientists monitoring global atmospheric carbon dioxide concentrations report that, for the first time in human history, CO2 levels could soon rise above 400 parts per million for a sustained period of time in much of the Northern Hemisphere."

"The U.S. military spent $5 million on incinerators at a base in Afghanistan that never became operable, forcing troops to use a type of open-air burn pit that has been linked to serious respiratory problems among veterans, according to a government report."

"At a glance, U.S. EPA's plan to cut an $11.5 million grant program in an effort to meet the sequestration mandate doesn't look like much given the agency's $8.5 billion budget. But that's a lot of money to state and local air regulators who have been counting on it."

"Wisconsin Power & Light Co. and three other utilities will spend $1.2 billion to clean up coal-fired power plants and shut down older plants under a settlement announced Monday with federal regulators."