"We're changing the chemistry of the atmosphere. And we're doing it in a way that has never happened in nature. We're doing it so quickly. Nature, of course, has had fluctuations. We've gone from warm periods to ice ages. But that's been over 1000s and 1000s of years. We're doing it at an unprecedented rate. The experiment’s started. If we stopped all emissions today it will still take over a century to find equilibration. At the same time that we're adding stuff to the atmosphere at an unprecedented rate, we're cutting down, we're destroying the only real safety that we have, which is the web of living green things all over the planet."