The crisis is a concrete threatening reality today. It stands to get catastrophically worse unless we take action before the accumulation [of] this global warming pollution reaches such toxic levels that the problem becomes bigger than we can solve.

[T]he scientific enterprise will never be completely free of mistakes. What is important is that the overwhelming consensus on global warming remains unchanged.

All I'm doing, all I have done for 40 years, is spend time with the best scientific experts, gain their confidence, and take advantage of their patience in explaining things to me over and over again in progressively simpler language that I can understand, so that I can read it back to them and get their sign off, where they say, "Yep, that's it, Al. You've got it." When I understand it, I know I can explain it to other people. When the scientists' predictions end up being true, I see that as an opportunity to say to people, "Listen carefully to what they're saying now."

I doubt nuclear power will play a much larger role than it does now.

It seems an easy choice - sacrifice the tree for a human life - until one learns that three trees must be destroyed for each patient treated. Suddenly we must confront some tough questions. How important are the medical needs of future generations?

The truth about the climate crisis is still inconvenient to the large carbon polluters. And so they want to bob and weave and dodge the truth, and pretend like it's still a big controversy, and it's not. They want to pretend that this is up for debate. Like, whether or not the world is round is up for debate, or whether the moon landing really took place.

The climate crisis is the greatest challenge humanity has ever faced. From not only the warming of the earth with higher global temperatures, but also from strengthening storms and expanding droughts to melting ice and rising seas, the costs of carbon pollution are already being felt by governments, corporations, taxpayers and families around the world. The climate crisis will affect everything that we love and alter the course of our future. Now, more than ever, we must come together to solve this global crisis. We must act decisively, rise to the occasion and solve this monumental challenge.