Meat is a wasteful use of water and creates a lot of greenhouse gases. It puts enormous pressure on the world's resources. A vegetarian diet is better.

We run enormous risks and we know what kind of reductions of greenhouse gases are necessary to drastically reduce risks. Reducing emissions by half by 2050 is roughly in the right ballpark. It would bring us below 550 ppm.

There's no shortage of Democrats who are at least as committed as Schwarzenegger to reducing greenhouse gases.

The basic scientific conclusions on climate change are very robust and for good reason. The greenhouse effect is simple science: greenhouse gases trap heat, and humans are emitting ever more greenhouse gases.

You could warm Mars up, over time, with greenhouse gases.

Sending a container from Shanghai to Le Havre emits fewer greenhouse gases than the truck that takes the container on to Lyon.