That's the thing with public opinion, you don't need a good justification to get things done, only a sufficient one. If a devastating asteroid did hit and NASA

That's the thing with public opinion, you don't need a good justification to get things done, only a sufficient one. If a devastating asteroid did hit and NASA/ESA/etc got all the funding they ever wanted to catalog the sky, and announced they'd finished 2 years later, a large slice of Joe Public would respond "you said the chances were 1 in a million last time. Why should we trust you now?" With the right resources that could be leveraged into a Mars colony with actual sustainability in mind. I think you'd find the threat of asteroids to be a much more relatable and palatable threat than Climate Change. It's an purely external force of nature that no human can claim responsibility for or point fingers over. An asteriod strike would also be the single, short-term-but-devastating situations humans have a evolved to deal with, as opposed to the long-term creeping rot of Climate Change. Likely much easier to get action over asteriods. Hell, asteroids are already #2 on the list of things NASA should focus on according to a recent PEW survey. https://arstechnica.com/science/2018/06/nasas-priorities-appear-to-be-out-of-whack-with-what-the-public-wants/ https://arstechnica.com/science/2018/06/nasas-priorities-app...