The "waste heat" generated by everyday activities in metropolitan areas alters atmospheric circulation patterns, warming or cooling temperatures across a large region.

Two leading climate-change researchers cast new light on one of the most prominent findings of the last major IPCC report, issued in 2007.

Even as the rest of the nation baked in 2012, Alaska froze. The contiguous 48 U.S. states saw their warmest year on record by far, but it was one of Alaska's chilliest.

West Antarctica is experiencing nearly twice as much warming as previously thought.

Though we’re still more than two weeks from the end of 2012, it’s not too soon to get a sense of how the year will go down in meteorological annals. Some of the signals from January to November are so strong that December won’t change the outcome.