The struggle against poverty in the world and the challenge of cutting wealthy country emissions all has a single, very simple solution... Here it is: Put a price on carbon.

This is by far the most serious crisis civilisation has ever faced.

We face a climate crisis now that is the most serious challenge our civilization has ever confronted. And the greatest country in the world [America] has to remain a part of this unprecedented global agreement to deal with it.

If the only tool we use to analyse what's valuable is a price tag, then those things that don't have price tags begin to look like they have no value.

Many of the green places and open spaces that need protecting most today are in our own neighborhoods. In too many places, the beauty of local vistas has been degraded by decades of ill-planned and ill-coordinated development.

John McCain is now openly endorsing the policies of the Bush-Cheney White House and promising to actually continue the same policies over again? Hey, I believe in recycling but that's ridiculous.

The interior of the earth is extremely hot – several million degrees.