To use a Southern euphemism, our space program has been snake-bit.

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?

When energy prices go up, the difficulty of projecting demand also goes up - uncertainty goes up.

At some point, a false belief collides with physical reality.

I think George W. Bush has a warm, engaging personality. But, you know, the presidency is more than just a popularity contest.

The climate crisis requires a bottom-up, grassroots demand for solutions because the elites in many parts of the world are under the influence of old industry.

The good news is, we have everything we need now to respond to the challenge of global warming. We have all the technologies we need, more are being developed.... But we should not wait, we cannot wait, we must not wait.