system
Given the following post, respond as if you're commenting on Reddit:
human
I think that the argument "Humanity shouldn't expand into space until we stop harming Earth" is utter nonsense. CMV

This argument is heard frequently in discussions of government funding for space exploration. It assumes some universal standard of fairness and natural duty, and that since we're failing to manage Earth  we are therefore unworthy of having anywhere else to play. It's a very parental sort of argument, akin to "You can't have any dessert if you don't eat your vegetables".

This is nonsense. If we are to learn any lesson from nature, it is that survival matters most. And homo sapiens has a much better chance of long term species survival if we have members in as many different locations as possible, since changing local conditions (solar flare, asteroid, epidemic) could wipe out a local population (like a single planet). Which means that getting genetically viable populations of humans off of Earth should be a higher priority than protecting Earth, since the state of planet Earth is irrelevant to human survival in the long run.
gpt
If we establish a functioning colony off-world, the human race will be able to survive disasters such as asteroids which cause mass extinctions on Earth every hundred million years or so.  However, politicians and colonists will also be able to survive man-made disasters such as massive nuclear barrages.  This ability to survive the destruction of the Earth's humans makes a massive nuclear strike much more likely to occur than 1:100 million.  And then the colony's likelihood of survival may be far from 100%.  So by colonizing other worlds without any solution to nuclear war other than "strike first", we may actually make the extinction of humanity more rather than less likely.