Just ask a mastodon how hot it was: atmospheric CO2 reaches 400 PPM
13 May 2013
The earth's atmosphere hit a scary milestone last week, as atmospheric CO2 surpassed 400 parts per million (PPM). The last time CO2 levels were this high, mastodons roamed the earth and human beings didn't even exist. For anyone counting, that was more than 3,000,000 years ago. And we humans accomplished this devastation in a mere 200 years - just three human lifetimes. At current rates of pollution, we'll crash through 450 PPM in a few decades - a level most scientists agree will be globally catastrophic.
As Al Gore said this week in the Huffington Post, "We have been recklessly polluting the protective sheath of atmosphere that surrounds the Earth and protects the conditions that have fostered the flourishing of our civilization." The idea that we can continue to do so without having a ruinous effect on the wellbeing of the human species is utter folly.