The first person to come up with the idea of global warming was a 19th-Century Swedish chemist.

Question: When did we first discover that humans could alter rnour climate? 

Bill McKibbon: The first person to even rncome up with the idea was in the late 19th Century, the great Swedish rnchemist Arrhenius who later won the Nobel for other work did some back rnof the envelope calculations about what would happen if we burned all rnthe coal that we were at that point beginning to burn. Oddly enough, hisrn numbers come not that far from what the biggest super computers on rnearth are now cracking out—but really nobody paid any attention until rnreally the 1980s. That’s when we had computers big enough to begin rneffectively modeling the climate and that was the first point at which rnscientists really began to sound the alarm. Probably Jim Hanson, the rnNASA scientist before congress in June of 1988 saying "Global warming isrn real" is as good a point as any to kind of pick as the starting date rnfor the global warming era. 

Question: If we had rnaddressed the issue in 1988, would we be in the same predicament we are rnin today? 

Bill McKibbon: We wouldn’t be in the same rnposition. We might still be going to have to deal with some mild effectsrn of climate change, but we would be well on our way now to having made rnthe transition away from fossil fuel. It’s going to turn out to be a rngreat, great historical shame that we didn’t pay attention when we knew rnwhat was going on. You know I wrote the first book about all of this 21 rnyears ago in 1989. At the time, I was 27 and believed that people would rnread the book—which they did, it was translated into 24 languages I rnthink—and then they would act and solve the problem, which they didn’t. 

Thern only thing we didn’t know 20 years ago when I wrote "The End of Nature"rn was how fast is this going to happen, where is the red line? Being rnhuman we all hoped that it was some ways away, so it would be somebody rnelse’s problem to deal with. Those hopes have been steadily evaporating.rn For the last 10 or 12 years it’s been very clear that the earth was rnmore finely balanced than we realized and that we were seeing change rnhappening ahead of schedule and on a larger scale than we expected, but Irn think if you were looking for a date, summer of 2007 when we saw the rnvery rapid melt of sea ice across the Arctic was really the pointed... Irn spent that summer getting phone calls from scientists I’ve known for a rnquarter century who have always been worried and concerned, but all of arn sudden were panicked, or saying no matter what physical phenomena we rnlook at we’re seeing this kind of violent flux. 

Question:rn Do you think it’s still possible to avert the worst effects of global rnwarming? 

Bill McKibbon: Everything is relative. We’rern not going to stop global warming, obviously. We’ve already warmed the rnplanet a lot. That’s what this new book “Eaarth,” that’s the point it rnmakes. This is already underway and in a big way, but what is bad can rnalways be made worse. If we don’t act soon then the stakes are really rncivilizational in scale. So far we’ve raised the temperature about one rndegree with another one degree locked in from the emissions we’ve rnalready put into the atmosphere. One degree has been enough to melt the rnArctic. Two degrees will do more damage, but if we don’t act very rnquickly, scientists are quite clear that the temperature will go up rnfour, five, six degrees in the course of this century and that’s just rnchange of a sort that we’ve never even contemplated.