https://www.nytimes....896ed87b2d9c72a
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.
After a brief lull, the temperatures and humidity began to rise again. On May 14, it was 51 degrees Celsius in Jacobabad, a city of almost 200,000, with a “wet-bulb” reading of 33.1 — just below the conventional estimate for the threshold of human survival, which is 35. More recently, scientists have suggested a lower threshold, even for the young and healthy, of just 31 degrees Celsius. Ten weeks in, the heat wave is testing those limits.
But just as remarkable as the intensity and duration of the South Asian heat wave is the fact that it is, already, not much of an anomaly at all.
We want to call events like this “extreme,” but technically we can’t, “because they’re not rare anymore,” Friederike Otto told me, from London, just as the heat wave reached its April peak.
Dr. Otto is a senior lecturer at the Grantham Institute for Climate Change at the Imperial College of London, whose World Weather Attribution group just published a “state of the science” briefing. Among other things, it concluded that climate change has made every single heat wave in the world both more intense and more likely.
She is herself a leading figure in the emerging field of climate attribution, which has grown increasingly central to the messy project of making sense of environmental and ecological disarray. With the impacts of warming growing evermore unmistakable, we no longer ask science only what to expect from further warming, but also how to quantify, categorize, conceptualize and narrativize the climatic anomalies we now encounter, somewhere in the world, almost daily.
A U.N. report published in April suggested that by just 2030 the world would be experiencing more than 500 major disasters each year. And the quickening frequency of what were once called “generational disasters” or “500-year storms” or even “acts of God” disorients us, too, so that it becomes hard to distinguish once-a-decade events from once-a-century ones — our disaster depth of field blurred by climate disruption. “What used to be a very extreme event is now probably not a very extreme event but something that we expect in this warmer climate quite frequently,” Dr. Otto said. “We really are in a quite different world.”
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