Scientists are telling us that 350 parts per million [of carbon] in the atmosphere is the upper limit. We're at 387 parts per million now, and we're up in that zone where the risk of going past irrevocable tipping points is elevated. It's no different than going to a doctor and learning your cholesterol is too high, and you're at risk for a heart attack. You have to work to lower your cholesterol and hope to get there before the heart attack comes.

Alone among businesses, the fossil-fuel industry is allowed to dump its main waste, carbon dioxide, for free.

Everything that the administration has done has been counterproductive.

With each month that passes, a solar panel gets 2 or 3 percent cheaper. So while we're holding the fossil fuel industry in check, the engineers in the renewable energy world are undercutting them from the other side.

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.

It drives me crazy to see so much of this planet's life so casually endangered. The first steps are so easy (drive smaller cars, for instance) that it's very hard to understand why we haven't taken them. But I know that this is the issue our generation will be judged by.

When you have solar panels, your electricity gets there for free, no one's figured out how to meter the sun yet. And that's good.