[Symmetry]

The Wizard and the Prophet, which I highly recommend, had a good section on the history of our worries about global warming. As per the article we've understood that increasing atmospheric CO2 would cause global warming for a very long time. What people thought for many decades, though, was that the CO2 we produced would mostly be absorbed by the oceans keeping the atmospheric concentration from getting too high. Figuring out that no, secondary effects would cause the oceans to re-emit that CO2 back into the atmosphere took many decades, into the 1960s I believe.