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.

To use a Southern euphemism, our space program has been snake-bit.

The climate crisis is the greatest challenge humanity has ever faced. From not only the warming of the earth with higher global temperatures, but also from strengthening storms and expanding droughts to melting ice and rising seas, the costs of carbon pollution are already being felt by governments, corporations, taxpayers and families around the world. The climate crisis will affect everything that we love and alter the course of our future. Now, more than ever, we must come together to solve this global crisis. We must act decisively, rise to the occasion and solve this monumental challenge.

Today we're dumping 70 million tons of global-warming pollution into the environment, and tomorrow we will dump more, and there is no effective worldwide response. Until we start sharply reducing global-warming pollution, I will feel that I have failed.

Atheists have just as much of a right to the public discourse as any ... people of any religious faith in this country.

The conversation on global warming has been stalled because a shrinking group of denialists fly into a rage when it's mentioned.

Most people in politics draw energy from backslapping and shaking hands and all that. I draw energy from discussing ideas.