National Resources Stewardship Program

Four hundred and forty million years ago, when CO2 levels are estimated to have been more than 10 times today's, our planet was in the depths of the coldest period in the last half billion years. At other times, high CO2 levels coincided with warm periods. There is no meaningful correlation with temperature in the geological record. Over the past half million years, the Antarctic ice core records show a remarkable link between temperature and CO2 . Yet, these records consistently show that temperature rises some 800 years before CO2 rises, not after it. Even over the past century the CO2/warming correlation is poor, with significant cooling taking place between 1940 and 1980 while human-produced CO2 emissions were increasing rapidly. In all these records there is no evidence to show that CO2 has ever acted as a climate driver or even as a significant secondary effect to accelerate climate warming.