Highest greenhouse gas concentrations for 2.1 million years

By analyzing shells buried under the Atlantic seabed, off the coast of Africa, researchers from the Lamont-Doherty Earth Observatory have determined that current atmospheric concentrations of greenhouse gasses are significantly higher than they have been for more than 2.1 million years. Whereas current levels are at 385 parts per million (ppm), the average over the span was a mere 280ppm, the same approximate level as existed in Earth’s atmosphere before the Industrial Revolution. One thing this work helps to confirm is that the current level of greenhouse gasses in the atmosphere is not part of any natural cycle that has taken place during the span in which human beings have existed. Our emissions are projecting the climate in a direction that is unprecedented in the history of human life.

The technique employed was based on examining boron isotopes in foraminifer shells. The work was published in Science.

Author: Milan

In the spring of 2005, I graduated from the University of British Columbia with a degree in International Relations and a general focus in the area of environmental politics. In the fall of 2005, I began reading for an M.Phil in IR at Wadham College, Oxford. Outside school, I am very interested in photography, writing, and the outdoors. I am writing this blog to keep in touch with friends and family around the world, provide a more personal view of graduate student life in Oxford, and pass on some lessons I've learned here. View all posts by Milan