Speaking of Gaia, I read Michael Lind’s Why we should embrace the end of human spaceflight on Salon yesterday with horror. He marshals a bunch of straw man arguments against humans in space, the worst of which is dismissing the threat of a planetary catastrophe:
“A sufficiently large asteroid or comet impact like the one that caused the extinction of the dinosaurs could do the job. But if a massive bolide threatened the Earth, we would send unmanned spacecraft, not Robert Duvall or Bruce Willis, to steer it away or destroy it.”
That’s a little complacent. Even if we ever get perfect asteroid defenses cracked you’ve still got to worry about cosmic strings, strangelets, radiation storms, Von Neumann probes, DNA hackers, the Yellowstone super volcano and anything shown on a Saturday afternoon on SyFi. All of our eggs are very much in one planetary basket.
Take the Gaia hypothesis to its ultimate conclusion: if the planet is a super-organism then humanity is the reproductive system. We’re the best bet to spread life beyond Earth and ensure its continued survival. The asteroid scenario may trigger panspermia but that would be for a lucky few bacteria, not Homo sapiens sapiens.
Colonizing space is difficult, expensive and for most people unappealing. But stop thinking about the planet you’re leaving to your children and start thinking about the universe you’re leaving to whatever our DNA based planetary ecosystem may evolve into.
A real environmentalist would focus on making this planet uninhabitable so we escape before it’s too late.