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.

January 2012

  • The Arctic of recent years—warmer, greener, less icy—is likely to be the new normal for the Far North. One sign of the ongoing transformation of the Arctic is the spread of shrubs across the tundra.