I'm still trying to figure out exactly what President Trump represents in American politics. But, if nothing else, he represents a way for tens of millions of people who were desperate for change to just turn the table over and say, we want to start over again. But it is a challenge for our democracy. It definitely is. But, again, the remedy has to be devoting enough attention to restoring the way we make collective decisions in this country.

Each and every one of us can make changes in the way we live our lives and become part of the solution [to climate change]

My parents were true believers in the efficacy of American constitutional democracy, and I was thoroughly inculcated with reverence for what we the people are capable of doing. The complication in that simple narrative is that as I got older, the Vietnam War shook my confidence in how our democracy was working. I ended up serving in that war, but it started with a lie, and I was very proud of my father for being one of its earliest opponents.

Anyone who deals with the climate crisis has an internal dialogue between hope and despair, because the challenge is so huge and the danger is so great and the stakes are so high. But I have always resolved that in favour of hope, and actually I'm more hopeful now than I was a decade ago when the solutions were visible on the horizon, but you had to seek reassurance that the technology experts that they're coming, they'll be here.

The consensus is clear. We need an immediate and determined shift to a clean, renewable economy. The continued mass burning of fossil fuels is inconsistent with a healthy, prosperous future for our civilization.

Science has a culture that is inherently cautious and that is normally not a bad thing. You could even say conservative, because of the peer review process and because the scientific method prizes uncertainty and penalises anyone who goes out on any sort of a limb that is not held in place by abundant and well-documented evidence.

When you're going through an emotional experience and you're focussed completely on what's happening, you can't even spare any attention that the camera's there.