 I mean, the fundamental measurement there is, what is the total energy of the sun? That's our main energy input to the Earth. The only other form of energy is the geothermal energy that, like in volcanoes, comes from inside the Earth. But if you average that over the whole Earth, that's 10,000 times less than the solar energy coming in. So really negligible when it comes to what's determining the average energy of the Earth. The average energy of the Earth depends on whether that incoming energy of the sun is equal to greater than or less than the emission from the Earth of energy back out into space. That depends on the Earth's temperature. The higher the temperature, the more Earth is trying to shed that heat. And right now, we think the ability of the Earth to shed the heat has been reduced by the CO2 and greenhouse gases. And so that little bit of imbalance in the energy is what's causing the global warming. So that's a big study. And not only the causes of the global warming, but also what are the impacts of global warming. So there are impacts on the vegetation distribution, on the seasons, the growing season is lengthening. Some trees now are slightly migrating northward. Usually people say we should look at the trees, two states south of us, to see what we're going to have in the next couple of decades in our state, say here in Maryland. We look two states south. So maybe we'll have Georgia peaches up here before too long. And things growing here are not going to be able to grow so well. They're going to have to move north. And then of course the Canadians worry about where will their plants move, because the closer you get to the pole, the more you kind of run out of areas that are cool enough. Birds of course, some birds like the snow goose migrate to Greenland to nest. And so Greenland is melting what will the snow goose do? So impacts on the weather, on species, and of course on us. And we depend on those other species.