I've always been more interested in organisms that can move on their own than in stationary plants. But when I canoe or hike along the edge of lakes or oceans and see trees that seem to be growing out of rock faces, I am blown away. How do they do it?

The failure of world leaders to act on the critical issue of global warming is often blamed on economic considerations.

The future doesn't exist. The only thing that exists is now and our memory of what happened in the past. But because we invented the idea of a future, we're the only animal that realized we can affect the future by what we do today.

If America wants to retain its position as a global power, its president must listen to the people and show strong leadership at this turning point in human history.

As an explorer, I know firsthand there are many places in the ocean so full of life that they should be protected. Coral reefs and mangrove coastlines are stressed already by climate change and ocean acidification, and poor planning will just make their plight worse.

Red carpet dressing all depends on the climate. I think richer, deeper colours are more flattering on the body, but the opposite is true if you are in Cannes or St. Tropez where the light makes deep colours look heavy and unflattering.

Though dams and artificial lakes can have significant negative environmental impacts, when carefully considered, mitigated, and managed, the benefits of hydropower often outweigh these costs.

I think governments will increasingly be tempted to rely on Silicon Valley to solve problems like obesity or climate change because Silicon Valley runs the information infrastructure through which we consume information.