The biggest hope at this point honestly is that fewer people are having kids and we're on track to halve the world population in another couple generations. Greenhouse emissions cut by half.
The per capita emissions of USA/Canada/Gulf countries have to be cut by a factor of 8-10 to reach sustainable levels. The per capita emissions of EU/China/SEA have to cut by 4 to reach sustainable levels. All within the next 25 years if we want to avoid crossing tipping points.
Halving the population in 50 years is not a realistic plan.
I haven't read up on all the assumptions made for those projections. If something unassumed pops up that makes things substantially worse then the population peak would come earlier I guess. But that's a gamble.
Halving the population in 50 years is not a realistic plan.