“The latest computer modeling I’ve seen indicates that at mid-century, there might be 150 million people classified as “environmental refugees.””

Where people aren’t as deeply reliant on fossil fuel as in the United States, it’s far easier for them to imagine change on this scale. When you go to Europe, they’re much more ready. They use half the amount of energy per capita that we use. They can imagine using less than that. They see the benefits. They’re ready to go.

If we continue to think of ourselves mostly as consumers, it’s going to be very hard to bring our environmental troubles under control. But it’s also going to be very hard to live the rounded and joyful lives that could be ours. This is a subversive volume in all the best ways!

We’re going to need that kind of movement, because the fossil fuel industry is a sprawling adversary – at work everywhere, its tentacles in everybody’s politics, invulnerable, I think, to direct frontal assault, but probably more brittle than it guesses if we come at it from all sides.

Especially in recent years, the more and more we understand what we are doing, the more we have the science to tell us what we’re doing, the fact that we continue to do it without taking steps to address it strikes me as, among many other things, irreverent in an extreme.

Ice in the West Antarctic and over Greenland, i.e., ice that’s over a rock at the moment, that will raise the level of the sea as it slides into the ocean, putting at risk everyone and everything that lives on the coasts, and that includes an enormous percentage of the world’s people.

We have built a greenhouse, a human greenhouse, where once there bloomed a sweet and wild garden.

Everything that the administration has done has been counterproductive.

My guess is that liberating the fossil fuel industry to frack anywhere they want will drive down the rate at which we’re converting to sun and wind. And it’s entirely a rate problem at this point.

Renewable energy is far more labor-intensive than fossil fuel production.

But tolerance by itself can be a cover for moral laziness.

I’m probably the wrong person to ask. My partner in much of this work [climate movement], who really came up with the divestment campaign with me, Naomi Klein, I think has written powerfully about this.

[Barack Obama] done some good things, he’s done a couple of bad things. He’s obsessed with this all of the above energy policy and… lots and lots of drilling in the States, so he’s been weak on it.

What makes us different? We’re the creature that can decide not to do something that we are capable of doing.

Probably more than anything else, the place that we really see the effects of the power of even the relatively mild temperature increases so far is in the melting of everything frozen on the planet.

The movers and shakers on our planet, aren’t the billionaires and generals, they are the incredible numbers of people around the world filled with love for neighbor and for the earth who are resisting, remaking, restoring, renewing and revitalising.

If you were running a solar company you may be okay – you may be able to keep growing. The question for physics is: Can you grow fast enough to begin to catch up with the damage?

When you fully understand the situation, it is worse than you think.

Environmental pollution is an incurable disease. It can only be prevented.

The environmental crisis is a signal of this approaching catastrophe.

In all matters moderation is desirable. If a thing is carried to excess, it will prove a source of evil.

In general, any productive activity which introduces substances foreign to the natural environment runs a considerable risk of polluting it.

The proper use of science is not to conquer nature but to live in it.

My entry into the environmental arena was through the issue that so dramatically – and destructively – demonstrates the link between science and social action: nuclear weapons.

In every case, the environmental hazards were made known only by independent scientists, who were often bitterly opposed by the corporations responsible for the hazards.