Even if we planted a tree on every square yard available in the planet by the end of the century we would only capture at most 10 percent of the CO2 we need to reduce. This does not mean that we should not plant trees; we should, for biodiversity's sake, and for our long-term future together with the other species.

The consensus is that climate change ranks along with nuclear warfare as the top two risks facing human civilization.

Climate change is new and complex. We don't have all the answers.

Trying to conserve a privileged global position makes change traumatic for the US.

Carbon negative power plants can provide energy while they overcome poverty and change economic values in the right direction.

The sun is the source of all energy on planet Earth and we cannot experiment with our only energy source.

Technology is a many-headed monster and perhaps it would be better to regress to a safer past and avoid technological change; it is tempting to think like that.