Earth Changes
2004 and Beyond


1000 Years of Atmospheric 
Carbon Dioxide History

Pieter Tans, Ph.D.: Senior Scientist, NOAA's Climate Monitoring and Diagnostics Laboratory

"The plot shows the last 1000 years of atmospheric CO2 history as measured in air bubbles in ice cores and since 1958 directly in the atmosphere." Graphic 2004 by Pieter Tans.

As one can from the above graph, the level of CO2 in the air has been essentially flat for 900 years. Then, year after year since 1900, it has gone almost straight up. For sure, something dramatic has occurred over the past 100 years to disrupt our planet's ability to maintain a healthy balance of CO2 in the atmosphere. To the scientist and the layman alike, this should be as startling as it is obvious. I suspect it is resulting from a combination of fossil fuel pollution and increased output of solar energy from our sun. 

To make matters worse, we now find ourselves with far less plant life available to remove CO2 from the air in order to produce the oxygen we breathe. Equally concerning is the rapid increase in the levels of CO2 absorbed by the oceans, which may now have reached their saturation point. Further warming of these waters will release the massive quantities of CO2 they hold like a sponge. Finally, as the soil and tundras warm, they too can release enormous amounts of CO2 into the atmosphere. Add it all together and the ingredients for a runaway greenhouse effect and further global warming are firmly in place. All of the above have been in delicate balance for ages. That is now changing faster than those who are aware can comprehend.   

Atmospheric concentrations of CO2, the gas primarily responsible for climate change, have been rising since records began in 1958. The rate of increase has risen from around 0.8 parts per million (ppm) per year in the 1960s to around 1.5 ppm per year in the 1990s.

Since 2000 the pace has accelerated further, with year-on-year rises of 2.1 and 2.5 ppm peaking with an increase of 3.01 ppm in the 12 months ending in August 2003 (New Scientist print edition, 9 October).



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