 This was taken from work by a variety of people, and especially by Jim Zachos, and it was used in a report of the U.S. government, the CCSP, that I helped with a little bit. And so we'll draw you a dinosaur over here, poor dinosaur, because right here, 65 million years ago, this big meteorite came zinging in and the poor dinosaur was wiped out. And what we have is time since then, from 65 million years ago on your left, running up to today on your right. And this is sort of no ice on the planet down here right after the dinosaurs, and then you start to get ice in East Antarctica and then West Antarctica. So over here it is icy. And what you can see down here are estimates of temperature. In a no ice world, it was pretty hot, and then it cooled off as we went the ice, and this was primarily because of dropping CO2. And right here, there's this little blip. It was already hot, and then in a reasonably short time of sort of 10,000 years, the temperature went way up, and then over 100 or 200,000 years, the temperature came back down. And that had all sorts of implications for living. Things, it changed rain, it changed to live where, it drove evolution, it drove a whole bunch of things. And it was caused rather clearly by CO2 being belched out of the Earth system in various places.