John Holdren

Any objective look at what science has to say about climate change ought to be sufficient to persuade reasonable people that the climate is changing and that humans are responsible for a substantial part of that - and that these changes are doing harm and will continue to do more harm unless we start to reduce our emissions.

Humanity cannot afford to muddle through the rest of the twentieth century; the risks are too great, and the stakes are too high. This may be the last opportunity to choose our own and our descendants’ destiny. Failing to choose or making the wrong choices may lead to catastrophe. But it must never be forgotten that the right choices could lead to a much better world.