"Many urban streams have become salty enough to harm aquatic life, largely because of salt used for deicing roads in the winter, according to a new government study released Wednesday."

"About 50 medical waste incinerators nationwide will have to reduce their air pollution under new regulations announced Wednesday by the Environmental Protection Agency."

Worldwide sea-surface temperatures for this August and this summer were the warmest in at least 180 years, the National Climatic Data Center said. The sea-ice minimum was well behind the extraordinary retreat of 2007.

"The World Meteorological Organisation said Wednesday that the ozone hole is expected to be smaller in 2009 than a year ago."

"More children equal more carbon dioxide emissions. And recent research has resulted in renewed coverage of the notion that one of the cheapest ways to curb emissions in coming decades would be to provide access to birth control for tens of millions of women around the world who say they desire it."

"Climate change activists reacted sharply yesterday to indications from Senate Majority Leader Harry Reid (D-Nev.) that cap-and-trade legislation may have to wait until 2010, warning that the delay could derail international negotiations in Copenhagen."

"The Obama administration signaled Wednesday that it would scrap a controversial Bush-era rule that set stricter limits for smog but fell short of scientific recommendations."

"The Interior Department announced on Wednesday that it was ending an oil and gas royalty program that ignited a scandal last year when it was disclosed that federal employees had engaged in corruption, drug use and sexual misconduct with oil industry officials."

The U.S. State Department issued an international proposal jointly with the governments of Canada and Mexico this week to phase down the production and consumption of hydrofluorocarbons (HFCs) starting as early as 2011.