Carbon dioxide - part 2 – University of Copenhagen

27 September 2008

Carbon dioxide - part 2

It could also be that those that promote the idea that CO2 levels follow global temperature changes rather than leading are right?

Ice cores tell us that during the last many glacial ‐ interglacial transitions, CO2 and temperature changed together, probably with a small lead of temperature. The best explanation of glacial‐interglacial changes I've ever heard is that rather small changes in the Earth's orbit force small changes in the temperature, which are then amplified by feedbacks in the climate system, of which CO2 is one, and the ice‐albedo‐feedback is another. This means that although temperature may lead CO2 slightly, CO2 does not change merely as a consequence of changing temperatures, but is also a cause for further temperature change. There is simply no known forcing that could produce glacial‐interglacial transitions alone, so it must be a complex combination of different factors and feedbacks.

-- Sune O. Rasmussen, post doc