I'm not a vegetarian, but I have cut back sharply on the meat that I eat.

Even though it's important for all of us to change our light bulbs and the vehicles we drive, it's much more important to change our laws and policies. I drive a hybrid and we've changed our light bulbs and windows and installed solar panels and geothermal ground source heat pumps and most everything else. But putting the burden on individuals to solve this global crisis is ultimately not going to be the most effective way to solve it.

Two thousand scientists, in a hundred countries, engaged in the most elaborate, well organized scientific collaboration in the history of humankind, have produced long-since a consensus that we will face a string of terrible catastrophes unless we act to prepare ourselves and deal with the underlying causes of global warming.

We have to abandon the conceit that isolated personal actions are going to solve this crisis. Our policies have to shift.

I think the cost of energy will come down when we make this transition to renewable energy.

The global warming deniers persist in this air of unreality. After all, the entire north polar icecap, which has been there for most of the last 3 million years, is disappearing before our eyes. Forty percent is already gone. The rest is expected to go completely within the next decade. What do they think is causing this?

The entire North Polar ice cap is disappearing before our very eyes. It's been the size of the continental United States for the last 3 million years and now 40 percent is gone and the rest of it is going.