These things are happening in large measure because of us. We in this country burn 25 percent of the world's fossil fuel, create 25 percent of the world's carbon dioxide. It is us - it is the affluent lifestyles that we lead that overwhelmingly contribute to this problem. And to call it a problem is to understate what it really is. Which is a crime. Crime against the poorest and most marginalized people on this planet. We've never figured out, though God knows we've tried, a more effective way to destroy their lives.

We, all of us in the First World, have participated in something of a binge, a half century of unbelievable prosperity and ease. We may have had some intuition that it was a binge and the earth couldn't support it, but aside from the easy things (biodegradable detergent, slightly smaller cars) we didn't do much. We didn't turn our lives around to prevent it. Our sadness is almost an aesthetic response - appropriate because we have marred a great, mad, profligate work of art, taken a hammer to the most perfectly proportioned of sculptures.

I also think we need unconventional political action, and I increasingly think that there is a need for people of faith to be able to do the kind of things that people of faith did 40 years ago in the heat of the civil rights revolution. This is a moral issue of every bit as much importance requiring every bit as much sacrifice, courage, and energy as that crisis did.

Global warming is no longer a philosophical threat, no longer a future threat, no longer a threat at all. It's our reality.

We finally know where the red line for climate really is. After the rapid melt of arctic ice in the summer of 2007, our best scientists, led by NASA's Jim Hansen, went back to work and produced a series of papers showing that with more than 350 ppm (parts per million) of carbon dioxide in the atmosphere, we couldn't have a planet "similar to the one on which civilization developed and to which life on earth is adapted."

If we all used clotheslines, we could save 30 million tons of coal a year, or shut down 15 nuclear power plants. And you don't have to wait to start. Yours could be up by this afternoon. To be specific, buy 50 feet of clothesline and a $3 bag of clothespins and become a solar energy pioneer.

All the science in the last few years, or almost all of it, really serves to show that the [climate] effects are larger and more rapid than we had thought even a decade ago.