A look at the biggest climate change stories of our generation, from the Gulf oil spill, Cancun climate talks, and flooding in Pakistan.
Smog and haze hover over Salt Lake City. The thick layer of smog lingering over Utah has fouled the state's mountain air so badly that health officials have warned people not to exercise outside and schools are keeping children inside for recess and sports. The smog is blamed on a weather phenomenon that pins pollution to the valley floors. Brian Nicholson/AP