It's off the charts - and if you don't believe the scientists, ask the insurance industry, the people we pay to analyze risk in our society.

We'd won the argument 15 years before, we were just losing the fight. And so it became clear to some of us that we would need to organise to fight, that we weren't going to win.

One of my favorite places is the Maldives, an all-Muslim nation in the Indian Ocean with a culture that stretches back 5,000 years. But since the highest point in the archipelago is a meter or two above sea level, even the next hundred are not guaranteed. They've committed to becoming the first carbon-neutral nation on Earth by 2020, building windmills as fast as they can.

There's no huge mystery. If you dig up huge amounts of carbon, huge amounts of ancient biology, hundreds of millions of year's worth of ancient biology, and flush it into the atmosphere in a matter of decades, then it stands to reason that we're going to have enormous effects, and now we can see those effects all around us.

If we had about 100 years, that sort of slow cultural conversion would be exactly the thing to do. But physics is calling the tune here. We've got to respond to a timetable that physics has set for us.

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.

I think that some of it is electoral - helping candidates that are willing to take dramatic actions, not just to say a few words about how climate change might be a problem.