Consider what kind of car you get. Buy cars and other products that have the least impact environmentally.

The truth is that we're at a critical juncture in the history of our species and if we don't act soon, we could inhabit a world we don't recognize anymore. But the most important truth is that we are capable of stopping climate change before the worst of its consequences are locked in. The solutions exist - all we need is the will to do something about it.

And just as the false assumption that we are not connected to the earth has led to the ecological crisis, so to the equally false assumption that we arenot connected to each other that has led to our social crisis.

There's an old African proverb that says "If you want to go quickly, go alone. If you want to go far, go together." We have to go far - quickly. And that means we have to quickly find a way to change the world's consciousness about exactly what we're facing, and why we have to work to solve it.

As important as it is to change the light bulbs, its more important to change the laws

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 scientific evidence of how serious this climate crisis is becoming continues to amass week after week after week.