There are serious scientists who argue, for instance, that should global warming become too grave a threat, we can counteract it by reengineering the atmosphere. Some schemes involve scattering sulfates into the stratosphere to reflect sunlight back out to space; others involve shooting water droplets over the Pacific to brighten clouds. If none of this works and things really go south, there are those who maintain people will still be OK; we’ll simply decamp to other planets.
