A polar vortex dipping down from Siberia is bringing a cold front with frigid temperatures to millions Americans. See maps of ...

New research reveals the Arctic is changing fast as permafrost regions are warming, forests are stressed, and flooding is ...

Millions are bracing for subzero wind chills this weekend as the coldest air of the season hits most of the country. The ...

"The most climate-stressed regions all contained permafrost, which is vulnerable to thaw as temperatures rise," researcher Sue Natali said.