That's an incredibly confident statement that very much misses the point. 50% loss of the global human population means we don't come back to the current level

That's an incredibly confident statement that very much misses the point. 50% loss of the global human population means we don't come back to the current level of technological development. 80-90% means we go back to the stone age. Photosynthesis stops working at temperatures very close to our current high temps. Pollen dies at temperatures well within those limits - we're just lucky we haven't had massive heatwaves at those times in the year. People need to understand that climate change isn't a uniform bumping up of the thermostat - it's extra thermal energy that exists in a closes system. That extra energy does what it wants, when it wants, in ways we can't currently accurately predict. It could be heatwaves that kill off massive swaths of global food production. Or hurricanes that can spin up and hit any coastline at any time of year. Or a polar vortex that gets knocked off the pole and sits over an area of the globe where the plant and animal life has zero ability to survive the frigid temperatures. It's not a matter of getting to wear shorts more often. We're actively playing russian roulette with the future of humanity.