Diplomats from almost 200 countries met in Copenhagen, Denmark, to huddle, confer, cajole, and eventually forge the structure of a new global agreement to reduce carbon emissions.

Spurred by a warming climate, daily record high temperatures occurred twice as often as record lows over the last decade across the continental United States, new research shows.

How do people and organizations respond to extreme weather events—in particular, flash floods? Flash floods are already on average the leading cause of weather-related fatalities in the United States and second most common worldwide.

Every snowfall is different, including how much water is packed into the flakes and how that changes over the life of a storm. This can make it very hard to figure out how much snow “really” falls in a given storm.

Dione Lee Rossiter, University of California, Santa Cruz • This Ph.D. student studies clouds, especially over the subtropical ocean—the area just north and south of the tropics. She's interested in their invisible physical changes, or microphysics, and a whole lot more.