"Billions of tons of carbon are buried in the frozen Arctic tundra, now heating up because of human-caused climate change. To measure which greenhouse gases are being released and in what quantities, government scientists are flying instrument-laden planes over the tundra from now through November."

"Researchers found that two of the Tetons' biggest glaciers have lost more than 20 percent of their surface area since the late 1960s."

"UN Secretary General Ban Ki-moon is to visit a Norwegian island deep inside the Arctic Circle, near the North Pole, to see firsthand the effects of climate change, his spokeswoman said."

In Brazil's epicenter of deforestation, an environmental group is offering farmers cash to let the forest stand. The question is whether they can make more by clearing the land and farming it.

"Midwestern Democrats, who want duties placed on countries who don't limit greenhouse gas emissions, are at odds with Obama."

"July was the hottest the world's oceans have been in almost 130 years of record-keeping. ... Meteorologists said there's a combination of forces at work this year: A natural El Nino system just getting started on top of worsening man-made global warming, and a dash of random weather variations. The resulting ocean heat is already harming threatened coral reefs. It could also hasten the melting of Arctic sea ice and help hurricanes strengthen."

"Beetles and fire, twin plagues, are consuming northern forests in what scientists say is a preview of the future, in a century growing warmer, as the land grows drier, trees grow weaker and pests, abetted by milder winters, grow stronger. Dying, burning forests would then only add to the warming."

"Mexico is suffering from its driest year in 68 years, killing crops and cattle in the countryside and forcing the government to slow the flow of water to the crowded capital."

"Since the mid-1990s, hurricanes and tropical storms have struck the Atlantic Ocean with unusual frequency -- or have they? Two new studies suggest that the situation may not be so clear."