NCAR researchers are studying whether the eruption of Indonesia’s Mt. Toba supervolcano about 70,000–75,000 years ago may have cooled Earth enough to initiate an ice age and potentially alter the course of human evolution.

Melting of the Greenland ice sheet may drive more water than previously thought toward the already threatened coastlines of New York, Boston, Halifax, and other cities in the northeastern United States and Canada.

One of the challenges for global climate modelers is accurately simulating cloud cover and its changes over time. This is vital for projecting future temperatures, rainfall, and other aspects of global and regional climate change.

Rivers in some of the world's most populous regions are losing water, according to a new comprehensive study of global stream flow.

The threat of global warming can still be greatly diminished if nations cut emissions of heat-trapping greenhouse gases by 70 percent this century, according to a new analysis.