Washington Post: Ezra Klein: In 2005, when An Inconvenient Truth came out, I remember that the hope was we could keep the carbon load in the atmosphere to 350 parts per million, and the fear was we would hit 400ppm. Now weve hit 400ppm and people are hoping to avoid 450ppm. This seems to be getting out of hand, and fast.
Al Gore: We have already crossed the 400 parts per million mark. We crossed it earlier this year. The question now is how high it will go before we begin bending the curve. But in spite of...