News Blog

Jun 18, 2009 02:30 PM in Environment | 9 comments

Stable ancient atmosphere underscores current greenhouse spike

By Katherine Harmon

 
e-mail print comment

carbon dioxide levels highDespite vast changes in climate since the early Pleistocene, 2.1 million years ago, carbon dioxide levels have stayed pretty stable until lately, according to a study published online today in Science.

All of that consistency, in which peak CO2 levels averaged 280 parts per million, makes today's concentration—385 parts per millions, which is 38 percent higher—all the more stunning, the authors report. Previous work showed stable CO2 levels going back about 650,000 years. 

For the new estimate, the researchers analyzed ancient plankton shells beneath the Atlantic Ocean floor, rather than relying on data from polar ice cores, which can only give readings for the past 800,000 years. The tiny shells provided info on CO2 levels as well as temperature and ocean acidity.

The findings suggest that previous ice ages may have had more to do with other forces, such as changes in the Earth's orbit, than with plummeting levels of carbon dioxide in the atmosphere. But, spikes in CO2 levels did match up with periods of warming.

"Our data continues to suggest that greenhouse gases and global climate are intimately linked," lead study author Bärbel Hönisch, a geochemist at Columbia University's Lamont Doherty Earth Observatory, said in a statement.

Image of Bärbel Hönisch diving for plankton courtesy of Steve Doo

Read More About: carbon dioxide

Share
Propeller    Digg!  Reddit delicious  Fark 
Slashdot    RT @sciam Stable ancient atmosphere underscores current greenhouse spikeTwitter Review it on NewsTrust 
sharebar end

You Might Also Like


Discuss This Article


Click here to submit your comment.

VIEW:

2,573 characters remaining
 
  Email me when someone responds to this discussion.
 

risk free issuefree gift

Sciam - cover Email:
Name:
Address:
Address 2:
City:
State:  
spacer



Most Popular Blog Posts


Editor's Pick

  • Adapting to the Freshwater CrisisForward-thinking experts are getting a better handle on the growing global water shortage and coming up with innovative approaches to ensuring the security, safety and sustainability of this resource

Newsletter

Environment Newsletter

Get weekly coverage delivered to your inbox


 Podcasts

  • 60-Second Earth     RSS  · iTunes The Jellyfish Menace
    click to enable

    Download

  • 60-Second Science     RSS  · iTunes Plants Share Light If Neighbor Is Related
    click to enable

    Download





ADVERTISEMENT
 
 


Also on Scientific American


© 1996-2009 Scientific American Inc. All Rights Reserved. Reproduction in whole or in part without permission is prohibited.
ADVERTISEMENT