Top Scientists Sound Alarm on Warming

The Portage Glacier in Alaska has retreated significantly due to global warming.

Image: USA Today

A report from the Proceedings of the National Academy of Sciences warns of dangerous anthropogenic (human-causing) climate change. The research, led by James Hansen of NASA, found that the planet has warmed to the highest overall temperatures in the last 12,000 years. The journal Nature reported that 1,700 species of plants and animals have migrated poleward to find cooler climates. The most affected region is the far north, where glaciers are melting as a result of the change.

--The USA Today has more information