GENEVA (Reuters) - The hole in the ozone layer over Antarctica has already surpassed its 2007 size this year, and is set to keep growing for another few weeks, the U.N. weather agency said on Tuesday.

STANFORD, California (Reuters) - A four-foot-long helicopter flew itself over the Stanford University campus on Monday in a test of artificial intelligence that researchers say could be used to scout wildfires or on military missions.

ARGONNE NATIONAL LABORATORY, Illinois (Reuters) - Vast improvements are needed to extend the life and lower the cost of lithium batteries before they can efficiently power vehicles, a U.S. government official who tracks high-power battery development said on Monday.

Estimates of the impact climate change will have on wildlife may be much less reliable than thought, according to research that is reopening debate over a widely used modelling method endorsed by the Intergovernmental Panel on Climate Change (IPCC).

General Motors Corp on Tuesday unveiled the production model of its much-anticipated plug-in electric car, the Chevrolet Volt.

Chief Executive Rick Wagoner introduced the small, curvy vehicle at the automaker's Detroit headquarters during an event to celebrate its 100th anniversary.