Two years after the BP oil spill, oysters in the Gulf of Mexico contain high concentrations of the heavy metals found in crude oil.
Dolphins in the Gulf are dying at record rates. More than 700 have been found dead on the beaches of Alabama, Florida, Louisiana, and Mississippi.
The first criminal charges relating to the spill are filed against a BP employee for destroying evidence.
The retreat of glaciers in the Alps is causing the Matterhorn to crumble.
The 12-month period from May 2011 to April 2012 is the hottest in U.S. history.
Carbon dioxide levels in the atmosphere reach 391 parts per million, the highest in 800,000 years.
A blistering March sets more than 7,700 U.S. daily-high temperature records. More than 90 cities set monthly-high records. In the Midwest and Great Lakes states, average monthly temperatures are at least 10 degrees warmer than normal.
117,000 electric-drive vehicles are sold, compared with 78,000 in the first quarter of 2011—a 49 percent increase.
Birds are singing more loudly than they did 30 years ago in order to be heard above the urban din.
Left column, from top: iStockphotos by Suzifoo, SteveByland;
Right column, from top: iStockphotos by VisualCommunications, Tsuji, jangeltun