NEW STUDY CLAIMS THAT CO2 CAUSED RAPID WARMING 56 MILLION YEARS AGO

Here is an interesting article that attempts to equate a period of rapid warming in the past (56 million years ago) with the situation today where CO2 levels are increasing, as they apparently were then. The article does not give all the details needed to prove their case, in fact it raises quite a few questions. The first is, how can they be certain that it was not the warming which caused the CO2 level to rise rather than the CO2 which caused the warming? The article states that the ocean temperature was 10 degrees C warmer than now, which would mean that the oceans would dissolve much less CO2, meaning that atmospheric levels would be much higher. Also the level of CO2 at that time was believed to be much higher than now and the temperature was also much higher and yet there was no runaway warming. It peaked at about 5 degrees of increase and then reduced.