Humans on the Earth behave in some ways like a pathogenic micro-organism, or like the cells of a tumor.
Life does more than adapt to the Earth. It changes the Earth to its own purposes.
NASA will send up a big sun shade that will be in orbit between the earth and sun and deflect 2 or 3 percent of the sunshine back into space. It would be cheaper than the international space station.
We'd never have got a chance to go outside and look at the earth if it hadn't been for space exploration and NASA.
A billion could live off the earth; 6 billion living as we do is far too many, and you run out of planet in no time.
