Euan Mearns, Geologist: I don’t think humans have the power to alter the climate. I’ve been especially doubtful of the claim that CO2 in the atmosphere is a significant regulator of the earth’s climate. Even If we believe that CO2 is part of earth’s greenhouse gas effect that is making it possible for us to be alive, the CO2 component of earth’s atmosphere is increasing at only about 1 part per 100,000 every 5 years. It will take at least 1,500 years for earth’s CO2 component to increase from the current 40 part per 100,000 to 100 parts per 100,000. That would be 0.10% instead of the current 0.040%.