By an interesting coincidence, while I’m here enjoying WorldCon, the UK Guardian decided to run a story about the possible outcomes of contact with extraterrestrials. The money quote is this: “‘Green’ aliens might object to the environmental damage humans have caused on Earth and wipe us out to save the planet.”
While I agree this is theoretically possible, there is no reason to consider this any more likely than aliens attacking because they object to our over protection (as they see it) of our natural environment. It’s absurd even to speculate about what might provoke hostility from a member of another human culture without knowing anything at all about that culture. It even more absurd to speculate about what might provoke an unknown extraterrestrial culture. Anything we can imagine, and probably a great many things we can’t, might be the trigger.
Seriously, is it so hard to think up legitimate reasons to protect the environment that people have to come up with silly ones?