Climate change is happening, humans are causing it, and I think this is perhaps the most serious environmental issue facing us.

There is no debate in the scientific community...We need [Congress] to change things, not to deny what's happening.

I stand by my assertions that although you can know what happens to any individual species that you modify, you cannot be certain what will happen to the ecosystem. Also, we have a strange situation where we have malnourished fat people. It's not that we need more food. It's that we need to manage our food system better.

The debate [in Undeniable] was nominally about creationism as a "viable" explanation for what we observe around us. For my side, the debate went very well; I'm not sure what I would change, although I can imagine shortening my answers during the rebuttals, perhaps.

As my old professor Carl Sagan said so often, 'When you’re in love, you want to tell the world.’ And I base my beliefs on the information and the process that we call science. It fills me with joy to make discoveries every day of things I’ve never seen before. It fills me with joy to know that we can pursue these answers. It is an astonishing thing that we are — you and I are one of the ways the universe knows itself.

Science is the key to our future, and if you don’t believe in science, then you’re holding everybody back. And it’s fine if you as an adult want to run around pretending or claiming that you don’t believe in evolution, but if we educate a generation of people who don’t believe in science, that’s a recipe for disaster. We talk about the Internet. That comes from science. Weather forecasting. That comes from science. The main idea in all of biology is evolution. To not teach it to our young people is wrong.

I feel that I've often pointed out that there are countless aspects of life and nature that scientists and scientific thinkers cannot explain. Why the universe is accelerating in its expansion and what came before the Big Bang serve as compelling examples. The process of science provides a way to seek answers to those questions.