The History of Atmospheric Carbon Dioxide on Earth
2010-01-19 from:planetforlife author:
Atmospheric carbon dioxide during the last four ice ages.
This graph puts it all together. It is a record of the concentration of carbon dioxide during the past four ice ages. The green part is from: http://www.ncdc.noaa.gov/paleo/icecore/antarctica/vostok/vostok_co2.html The data comes from air bubbles trapped in ice taken from a two kilometer hole drilled into the Antarctic ice sheet. It is like the preceding Keeling curve except that it extends 415,000 years back in time instead of 50 years. The Keeling curve has been added to the right side as indicated by the black and red. The horizontal scale prevents showing any detail.
At 400 PPM, the amount of carbon dioxide currently in the atmosphere is unprecedented, at least in the past 415,000 years. The last time it reached even 300 PPM was 325,000 years ago.
The amount of carbon dioxide in the atmosphere is strongly correlated to temperature and glaciation. The record is jagged, but it is easy to see patterns. When the concentration is below 240 PPM, kilometers thick glaciers cover most of Europe, Canada and the northern part of the United States. There are 4 ice ages recorded here. Note that temperatures decrease irregularly over a span of approximately 100,000 years while temperature increases are sudden and dramatic. We live in an era just after a rapid temperature increase.
Conclusion If present trends continue, Earth's climate will be very different 100 years from now. Nearly all of the world's scientists agree on this. The only disagreement is about the amount and the rate of change.
Climatology is a very complex subject and the preceding is only a foretaste. An indepth report, written by 2,500 scientists from around the world, is available if you want to know more.
http://www.ipcc.ch/ The report was written by the Intergovernmental Panel on Climate Change.