Quick!! We need to fire up the DeLorean and go back and have FDR enact Carbon Credits along with Cap and Trade so that....errrummm, wait. It got better without .gov intervention? How did that happen? Especially if you look at the 40's and 50's when we burned more fossil fuels (war and post-war recovery) then we did in economically stagnant 30's when they were melting fast.... Maybe mankind and our actions HAVE NOTHING TO DO WITH IT.
I happen to think we do have something to do with global temp, but don't hang me yet, I don't drink the kool-aid. I wish someone would study the climate history of the last few hundred years overlaid with human activity. I theorize that during the little ice age we exacerbated a natural cooling trend with particulate emissions, during the early industrial revolution we were burning massive amounts of coal and wood in a very dirty fashion. Contemporary reports talk of the reduced daylight in places like London. You know, how Beijing looks now! Circa the civil war Virginia was nearly completely deforested, figure that's a little snapshot of lost air filters. High C02, lots of particulate=reduced surface heating. I think over the past century we've gotten a lot less particulate emissions along with a natural warming trend. I guess that stuff like that has a much higher effect on global temps than CO2. See Krakatoa, cooled the whole earth.