What happened that would cause such an increase I wonder. Hmm..
Option A: It's the cows and their methane-filled bowels. They just started pooping more during the Depression. (You know that was a stressful time, even for cows.)
Option B: Al Gore was born and God wanted him to have a mission in life.
Option C: Hell (and the North and South Poles) stopped freezing over when the Democrats took power.
Option D: The world population exploded, cutting down more trees than ever before; the burning of fossil fuels increased; millions upon millions of combustible engines produced more fumes than a Grateful Dead concert.
I'm going with Option A, no I mean D. But don't take my word for it. How about a group of scientists from around the world.
On Feb. 2, 2007, the United Nations scientific panel studying climate change declared that the evidence of a warming trend is "unequivocal," and that human activity has "very likely" been the driving force in that change over the last 50 years. The last report by the group, the Intergovernmental Panel on Climate Change, in 2001, had found that humanity had "likely" played a role.