Perhaps you could say that mountaineers are driven by ego or our competitiveness, but there's a lot more to it than that. Whether it's a huge face in the Himalaya or some crag in the woods behind your house, exploration offers us a unique perspective on the world that you can't really find anywhere else.

Specifically choose not to take a GPS. Just create a challenge. You can climb Everest or walk across Antarctica with minimal gear and still have that sense of adventure. But in terms of exploration, Google Earth has this world mapped down to the square foot.

Climbing, as my grandmother said, it's a pretty frivolous thing. She always wondered when I was going to get a real job. But climbing is a real job for me now, and I enjoy it. It's a gift that I'm able to do it, share adventure and motivation with people.

It's our human nature to explore. Tens of thousands of years ago, our species walked out of Africa, traveling far and wide across the entire planet, from the Arctic to the tip of Tierra Del Fuego, making us the most geographically diversified species on Earth.

No day is alike - I do many other things, and I'm very active in the environmental movement.

What is now called 'green architecture' is an opportunistic caricature of a much deeper consideration of the issues related to sustainability that architecture has been engaged with for many years. It was one of the first professions that was deeply concerned with these issues and that had an intellectual response to them.

Left unchecked, climate change risks not only making the poorest poorer, but pulling the emerging middle classes back into poverty, too.

Where Republicans encourage popular myths about taxes, spending, and climate change, Democrats tend to stoke our fantasies about the sustainability of entitlement spending as well as about the cost of new programs.