And they are already working on mass border militarization so they can gun down millions trying to survive.
Straight up coming down to "Do you have an industrialized plumbing system?" and "Do your buildings have A/C?"
So much of the future of humanity will be dictated by the machinery that guarantees access to the basic conditions of life. One reason why I am not bullish on the future of the American state. We're a country that loves social murder. We will gleefully box in our neighbors and let mother nature finish them off. Turn every minority neighborhood and rural community into the Superdome during Katrina.
Climate
Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.
As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades:

How much each change to the atmosphere has warmed the world:

Recommended actions to cut greenhouse gas emissions in the near future:

Anti-science, inactivism, and unsupported conspiracy theories are not ok here.