Paleoclimatologist Mark Pagani of the Yale Climate and Energy Institute is investigating how increases in carbon dioxide over time have affected the climate.
He measured the change in carbon dioxide by studying the chemical signatures of marine algae found in ocean sediment. Because marine algae are plants, which utilize carbon in photosynthesis, the chemistry of their molecules reflect changes in carbon dioxide levels. Pagani looked at the molecular components of algae going back one half million to five million years ago. What he found is that small changes in the amount of carbon dioxide or CO2 resulted in a big jump in temperature 3 to 5 million years ago, a period when temperatures were very warm.
“If today’s world is the equivalent to what we have evaluated for the past then if we stopped adding CO2 to the atmosphere right now and CO2 stayed at current levels then we would imagine at least a 2 to 2.5 degree increase in global temperatures.”
That’s 2 to 21/2 degrees celsius on average around the globe. A significant increase ---- enough to melt polar ice caps and cause a rise in sea levels. Pagani and his colleagues published their findings in the online edition of Nature Geoscience.
For WNPR, I'm Nancy Cohen.