> Countless human lives can be saved if we're willing to work together.
The major problem is equatorial heat. After a certain point of wet bulb temperature, you either die or migrate a billion people away from the equator into Europe.
Billions can't afford air conditioning. An air conditioning unit is equal to their entire annual income. You don't even have an airtight room within which you can install the AC unit. Let alone a stable electrical grid during heatwaves.
Their state capacity and wealth just isn't there to plan for the worst, either. Their civic society would sooner collapse than mobilise to solve this problem.
My intention isn't to sound chauvinist, this is just a reality of the political fragility of poorer countries, combined with the extreme difficulty of mobilising large amounts of resources to solve long-term challenges.