Tai Shan on his first birthday. The panda was conceived in 2005 through artificial insemination in a procedure performed by National Zoo scientists and veterinarians. Ann Batdorf/Smithsonian Institution via AP hide caption

itoggle caption Ann Batdorf/Smithsonian Institution via AP

Water in the atmosphere traps heat, like glass in a greenhouse. When there's less water vapor in the atmosphere, less heat is trapped. Space Frontiers/Getty Images hide caption

itoggle caption Space Frontiers/Getty Images

Goodell's most recent book, Big Coal: The Dirty Secret Behind America's Energy Future, considers the perils of coal dependency in America. Eric Etheridge hide caption

itoggle caption Eric Etheridge

Workers ride past cooling towers at a coal-fired power plant on the outskirts of Beijing. Such power plants are at the center of a debate about the future of energy production in China and the U.S. Frederic J. Brown/AFP/Getty Images hide caption

itoggle caption Frederic J. Brown/AFP/Getty Images

Smog shrouds the Los Angeles skyline. New ozone standards from the EPA aim to reduce smog, but may actually increase global warming. David McNew/Getty Images hide caption

itoggle caption David McNew/Getty Images

Haitians watch the L.A. County Search and Rescue working at a collapsed building in Port-au-Prince. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

The prolonged Arctic blast is now the worst cold spell seen in Scotland for almost 50 years, according to the country's first minister. Andrew Milligan/Press Association via AP hide caption

itoggle caption Andrew Milligan/Press Association via AP