Bob Brown reckons the aliens haven’t made contact with us yet because they’ve wiped themselves out like we’re destined to do. But he can relax. The aliens are alive and well and we’ll make contact with them once we’ve discovered the Mass Effect relays. So instead of trying to bring technological progress to a screaching halt, the greens should try doing all they can to support it.
Then, of course, the Reapers will wipe us out along with the rest of organic life as they do every 50,000 years or so, but at least humans won’t be to blame.