Several weeks ago, a group of scientists published a potential scenario in which Earth became uninhabitable by all forms of life. It was, admittedly, a worst-case scenario in which global warming eventually leads to a catastrophic explosion of gases completely destroying the environment conducive to any form of life with which we are acquainted.
The scary thing about this scenario isn’t that it will probably happen. It’s that it could happen. Scientists can’t rule it out absolutely. And as we get hints that life may have existed on other planets such as Mars and then died out when the climate changed, it becomes less difficult to imagine that something similar could happen to our own planet. And we already know that entire highly successful civilizations on our own planet have in the past been completely destroyed by environmental events such as floods, pandemics, earthquakes, and volcanic eruptions.
As an alternative, we are thousands of years away from being able to send pioneers to set up life on another planet to replace the one we’ve trashed. Right now, the estimates are that it would take a space ship at least 500 years to reach the nearest potentially habitable planet we know about. Setting up home elsewhere also assumes that humans can procreate in outer space, not a clear certainty, and that during the long trip, the voyagers in the space ship would not all murder each other or be wiped out by some other plague sweeping through the space ship.
It also assumes that once they landed, the planet would be habitable but not inhabited. Or at least not inhabited by any form of life that would not be apt to welcome a space ship full of humans. It’s a big ask.
Personally, I think working on climate change here on Earth is a better bet.