World is on a path for uncontrollable, fast methane release from all arctic permafrost and consequent short-term rapid warming - this will create a hot, humid world where wet-bulb temps will become deadly for billions of people living closer to equator than the poles, most of india, middle east, southern/central america,all of africa will have 50 Celsius weather for months.
Ocean fisheries and plankton will collapse, marine food chain can't operate at such warm weather.
This of course will start a huge migration towards the north and will trigger social collapse as western welfare systems stop working and goverments bow to populist demands - some form of civil wars/coups will be tried to maintain old order as brown masses of hungry, impoverished people stream north and become majority of population.
Its going to look like this:
https://www.france24.com/en/20190601-india-heatwave-temperatures-pass-50-celsius