Since last July, Earth’s average temperature has been at least 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels.
As global temperatures spiked to their highest levels in recorded history on Monday, ambulances were screaming through the streets of Tokyo, carrying scores of people who had collapsed amid an unrelenting heat wave. A monster typhoonwas emerging from the scorching waters of the Pacific Ocean, which were several degrees warmer than normal. Thousands of vacationers fled the idyllic mountain town of Jasper, Canada ahead of a fast-moving wall of wildfire flames.
By the end of the week — which saw the four hottest days ever observed by scientists — dozens had been killed in the raging floodwaters and massive mudslides triggered by Typhoon Gaemi. Half of Jasper was reduced to ash. And about 3.6 billion people around the planet had endured temperatures that would have been exceedingly rare in a world without burning fossil fuels and other human activities, according to an analysis by scientists at the group Climate Central.
These extraordinary global temperatures marked the culmination of an unprecedented global hot streak that has stunned even researchers who spent their whole careers studying climate change.
The low areas around the equator are experiencing more days every year with periods of temperature above human survivability. This means temperatures are too high for our natural evaporative cooling to work. Countries in the area do have some work arounds which is why we haven’t seen large scale deaths from these heat waves yet. Also AFAIK, these temperatures have only lasted a few hours at a time so far and over heating takes time.
As we go on like this though these periods will happen more often and last for longer, likely overwhelming the ability to compensate. It will also spread outside regions with such cooling infrastructure if we keep pushing it.
This is where we’re expecting at least a billion people to pick up and move, and we’re not entirely sure when that would happen. It depends on where the breakpoint is in the climate, and how tolerant the locals are of heat wave deaths.