Europe’s record-shattering New Year’s Day heat shows we’ve underestimated the risk of extreme climate events

This may sound familiar. The number of unprecedented climate and weather disasters has exploded in the past several years, suggesting that scientists underestimated the growing potential for extreme outlier events — such as 2022′s deadly and damaging heat wave in India and Pakistan, the destructive flooding in Yellowstone National Park and the U.K.’s all-time highest temperatures last July. Recent experience suggests that as the world warms, these events might not be such outliers.

Can’t rely on history

The climate of the present is no longer like the climate of the past — so looking backward isn’t a good way to gauge what the future might bring.

Underestimated impacts

Short-changing the potential for extreme events has wide-ranging implications for everything from emergency management to building and highway codes.

In some sense, this means the world is doubly unprepared: The extreme events themselves may exceed the predictions of both historical records and climate models, and the impacts on humans and other systems may leap past what computer programs warn about.

Diffenbaugh pointed out that the impacts of extreme events depend on how humans have prepared for them and that there are often there are tipping points beyond which that preparation fails. “There are lots of examples where you’re safe below the threshold, and there’s literal catastrophe beyond the threshold,” he said. “Flooding is a great example.” If a levee can handle a certain amount of water, everything is mostly fine up until that amount is exceeded — and then everything is very much not fine.

Not just a short-term problem

Using data that examines the world’s 215,000 glaciers individually, Rounce and his colleagues found that even at 1.5 degrees Celsius (2.7 degrees Fahrenheit) warming — the low end of Paris Agreement targets that is still achievable but slipping out of reach with each passing day — 26 percent of the ice present in 2015 will disappear by 2100. With more warming, that number could balloon to 41 percent. Globally, that’s as much as an 8 percent jump from previous best estimates, and in some regions — such as Alaska and the southern Andes — the difference is upward of 20 percent.

Rounce said that losing glaciers can have wide-ranging cultural impacts, and the melt will also contribute more to sea level rise than previously anticipated — 115 millimeters (4.3 inches) by 2100 if the current warming trajectory is maintained, or around half the amount of rise observed since 1880. And he added that while the new study’s projections are on the scale of decades, acute extreme events like heat waves can play a huge role in what actually happens to the world’s glaciers.