15 minutes outside of Port-au-Prince, along the shoulder of National Road 2, a sign from the Department of Tourism instructs people not to throw garbage. But this site has now become a makeshift dump, where rubble from the Jan. 12 earthquake is piled as far as the eye can see. Richard Harris/NPR hide caption

itoggle caption Richard Harris/NPR

A 60-mile-long iceberg known as B9B, right, crashes into the Mertz Glacier Tongue, left, in the Australian Antarctic Territory on Saturday. The collision created a new 48-mile-long iceberg. AP Photo/Commonwealth of Australia hide caption

itoggle caption AP Photo/Commonwealth of Australia

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

Tools like these ax heads from Vinelz, Switzerland, were used by Neolithic farmers and may have been part of their sex appeal to hunter-gatherer women. Sandstein via Wikimedia hide caption

itoggle caption Sandstein via Wikimedia

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

A large crack in the earth is seen in Port-au-Prince, Haiti, after a 7.0 magnitude earthquake Tuesday. Matt Marek/ American Red Cross via Reuters/Landov hide caption

itoggle caption Matt Marek/ American Red Cross via Reuters/Landov