There's no such thing as clean coal. It's non-existent. Theoretically, it might be possible, many years from now, to come up with a way to clean it as it's burnt. But there's not a single demonstration project in the United States. [...] Clean coal doesn't exist.

There is no doubt that the issue of race is always present in American politics and in the politics of any multiracial society. There is also no doubt that for some people it is an element in the manifested hostility to Obama. But I don't think it is the major theme at all. Obama is right when he reminds people: By the way, I was black before the election.

George Orwell once wrote that a false belief sooner or later collides with physical reality, usually on a battlefield.

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.

We have arrived at a moment of decision. Our home - Earth - is in grave danger. What is at risk of being destroyed is not the planet itself, of course, but the conditions that have made it hospitable for human beings.

The debate's over. The people who dispute the international consensus on global warming are in the same category now with the people who think the moon landing was staged on a movie lot in Arizona.

I saw the logarithmic growth of computer power.