I'm not entirely sure our reaction to dealing with the expected and unexpected effects of man's continual technological and global reach is to run global experiments that will impact everyone on earth without any democratic mechanism behind that decision.
It's more or less exactly how we got where we are now. "More of the same, but in the opposite direction" isn't very convincing.
Fun fact @akira2501, 2501 happens to be my exact karma right now. Which will probably dive a bit tonight. ;)
I don't see doing radical things to try to improve the earth as "exactly how we got where we are now." I see exploitation and capitalism & lack of governance & steerage as how we fucked shit up wicked bad. I see a lack of trying bold ambitious things to try and help rectify our situation as causing a colossal negative impact on earth, already, against our cloud cover, against our ocean oxygenation, against our planetwide survivable temperatures, against our more-moderate weather.
We need some big projects. The earth is huge, massive. To begin to have a real effect, we need to start, start making, start experimenting, start scaling. We can assess & learn as we go. We can adapt. With hope, we (Earth) can find sufficient leverage to not become another Drake Equation casualty.
What we cant do is what you propose: refuse to adapt. To gently seek peaceful global consensus, to reach unanimity before we start.
It's more or less exactly how we got where we are now. "More of the same, but in the opposite direction" isn't very convincing.