It doesn’t take the end of the world to upend the way billions live in it. The punishing weather we are uneasily learning to call “normal” is doing that already.
Late last month, a heat wave swallowed South Asia, bringing temperatures to more than a billion people — one-fifth of the entire human population — 10 degrees warmer than the one imagined in the opening pages of Kim Stanley Robinson’s celebrated climate novel, “The Ministry for the Future,” where a similar event on the subcontinent quickly kills 20 million. It is now weeks later, and the heat wave is still continuing. Real relief probably won’t come before the monsoons in June.
Mercifully, according to the young science of “heat death,” air moisture is as important as temperature for triggering human mortality, and when thermometers hit 115 degrees Fahrenheit in India and 120 in Pakistan in April, the humidity was quite low. But even so, in parts of India, humidity was still high enough that if the day’s peak moisture had coincided with its peak heat, the combination would have produced “wet-bulb temperatures” — which integrate measures of both into a single figure — already at or past the limit for human survivability. Birds fell dead from the sky.
In Pakistan, the heat melted enough of the Shipsher glacier to produce what’s called a “glacial lake outburst flood,” destroying two power stations and the historic Hassanabad Bridge, on the road to China.”