Well said. Ultimately knowing that it is too late (for those with the power) to prevent the feedback loop is not truly defeatist - or its opposite. Defeat and victory are no longer relevant here, the Climate Change Game (which we were never playing) is over, the scores are tallied.

I don't need to believe that 'my civilisation' will successfully survive after I die in order to want to improve it somewhat, or prepare for potential future generations. I try not to attend to such matters out of the expectation of success/reward or failure/punishment (y'know barring the part where me-want-eat), but because it is preferable for the world to be harmonious regardless of its fate. It's a happy coincidence that adaptation to climate/biodiversity collapse is also extremely compatible with, if not contingent upon, the kinds of systemic transformations I work towards.

"Before the doompill, chop wood, carry water. After the doompill, chop wood, carry water."