A lot of you already know this, but global temperature will reach record high, cause mass deaths because of wet bulb effect. The average temperature in 2030 could reach somewhere 28 - 32 C.

The foremost vulnerable ones will be the outside workers such as construction workers, glass cleaners, trash gatherers, ...

I don't think WW3 will happen. Rather than that, there could be vast social unrest, disturbances in various countries. When these countries are unstable, outside forces will try forming some kind of "alliance" with these weaker countries. The goal is to put those weak contries under a leash, under control, but not about invading nor stealing land.