As many know, the Chinese expression for "crisis" consists of two characters side by side. The first is the symbol for "danger," the second the symbol for "opportunity."

I think I may have a future as a disembodied head.

What's at risk [in 100 years] if we do not take action, truly is the survival of civilization as we know it... Literally that is the case. We have seen global warming so far of just a little bit less than one degree Celsius and look at what's happened. Superstorm Sandy. Boulder Colorado. All these fires. Hurricane Irene one year before.

It seems an easy choice - sacrifice the tree for a human life - until one learns that three trees must be destroyed for each patient treated. Suddenly we must confront some tough questions. How important are the medical needs of future generations?

Pollution should never be the price of prosperity.

Politics has become a game of meaningless, mindless battles, conducted by unscrupulous methods and people, designed to transform even the most serious policy debates into sport.

I'm naturally an optimist, but my basis for hope is rooted in my understanding of human nature.