I wish I had been old enough during the time we could’ve still made changes to make a difference.

Why? When you cared back then the frustration must have been at least the same it is now. The hope might have been bigger, but at the same time, you would have been part of a very small minority. And I think it would have been hard to endure that almost nobody you know thinks similarly. You might have been the only doomer they know. And how fast we manage to screw up our planet, you would have likely gotten old enough to come to the same conclusion you came to now: we won’t make it.