Neanderthals were pretty smart, and if we actively killed them off, then probably we did so in the same way that humans kill each other.

People sometimes say we need to be really almost on a wartime footing if you want to change. Our whole economy is based on burning fossil fuels, which is taking CO2 out of the ground and putting it up into the air.

There's this idea of shifting baselines. It was coined by a guy named Jeremy Jackson. It's the idea that every generation takes what it sees, and says, "Okay, well, that's the norm."

If in your lifetime you watch a species go extinct, or plummet almost to the point of extinction, that is a sign that something really serious is going on.

What are the Chinese doing, what are we doing, what are - so we need, both the developed world and the developing world, really need to be moving, once again, getting all your arrows in the same direction if you want to have any impact.

Increasingly developing countries are asking for aid to help deal with the consequences of climate change, which we don't want to give.

When you drive to the grocery store, your intention is not to change the world, it just happens to have that impact. So we've done a lot of things without even realizing it, and yes, just being unusual, as you say, does not put you above, in a sense, any of the other organisms with whom we share this planet.