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.

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.

After denial comes anger and finally, acceptance.

As difficult as it is to eliminate the risk of nuclear warfare, it requires fewer changes to the global economy than does averting or reversing climate change.

The new markets that arise from ecological constraints will dominate the 21st century economy, and so will markets for knowledge.

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

The "can do" logic, by its own nature, does not accept limits. And an empire does not have a graceful way to evolve out of this role. History demonstrates this time and again.