Climate Change & Global Warming

The annual average concentration of carbon dioxide (CO2) in the atmosphere stood at 395.3 parts per million (ppm) in 2013—a 27 percent increase compared to conditions before the Industrial Revolution. On May 9, 2013, the daily average concentration of CO2 surpassed 400 ppm for the first time at the Mauna Loa Observatory in Hawaii.

November 2011

  • Satellite observations show that as the Arctic tundra has grown warmer in the past three decades, it has also grown “greener.”

  • Phytoplankton productivity has increased 20 percent over the past decade as sea ice extent declines and more open water habitat is available.