31 May 2012:
C02 Milestone Reached
As Levels Hit 400 PPM Across Arctic
For the first time in at least 800,000 years, atmospheric concentrations of carbon dioxide have crossed the threshold of 400 parts per million (ppm)
, with stations across the Arctic recording these
record levels, the Associated Press
reports. Global concentrations have hit 395 ppm, but in recent months levels of carbon dioxide in the atmosphere surpassed 400 ppm in the Arctic because of the lack of CO2-absorbing vegetation in the Far North in winter and spring. Pre-industrial levels of CO2 were about 280 ppm, and numerous scientists said that hitting the 400 ppm threshold was a worrisome sign that industrial society continues to emit planet-warming greenhouse gases at an alarming rate. Jim Butler, global monitoring director at the National Oceanic and Atmospheric Administration’s Earth System Research Lab in Colorado, called the new high a “troubling milestone.” Carnegie Institution ecologist Chris Field, a leader of the Intergovernmental Panel on Climate Change, said, “It is an indication that we’re in a different world.” Levels exceeding 400 ppm have been recorded this spring in Alaska, Greenland, Norway, and Iceland.
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies
Yale Environment 360
articles are now available in Spanish and Portuguese on Universia
, the online educational network. Visit the site.
Business & Innovation
Policy & Politics
Pollution & Health
Science & Technology
Antarctica and the Arctic
Central & South America
Tribal people and ranchers join together to stop a project that would haul coal across their Montana land. Watch the video.
is now available for mobile devices at e360.yale.edu/mobile
An aerial view of why Europe’s per capita carbon emissions are less than 50 percent of those in the U.S. View the photos.
The 2015 Yale e360 Video Contest winner documents a Northeastern town's bitter battle over a wind farm. Watch the video.
video series looks at the staggering amount of food wasted in the U.S. – a problem with major human and environmental costs. Watch the video.
video goes onto the front lines with Colorado firefighters confronting deadly blazes fueled by a hotter, drier climate. Watch the video.
A three-part series Tainted Harvest
looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup. Read the series.