By David Flickling for the Washington Post/Bloomberg

By Seth Borenstein for the Associated Press

By Heather Kostick for the Penn Center for Science, Sustainability and the Media

By Lily Jamali for NPR

By Heather Kostick for Penn Center for Science, Sustainability and the Media

By Dinah Volyes Pulver for USA Today

By Matthew Rozsa for Salon

By Dr. Michael E. Mann, Shannon Christiansen, and Dr. Michael Kozar

By Tom Yulsman for Discover Magazine