[AnthonyMouse]

The idea that humans can colonize other planets is plausible. You send a thousand smart people to Mars with the right supplies and equipment and they could use it to build a self-sustaining infrastructure that then grows into a community of millions.

The idea that ten billion humans are going to take off in spaceships and abandon the Earth is utterly preposterous. The last human on Earth will die on Earth, not leave it for some other place.