Climate change impact on Storm Uri unclear: experts
The extent to which climate change could have been a factor in Storm Uri, which rocked Texas and other southern US states last month, causing millions to lose electricity and power, is unclear, according to weather experts.
The storm, for which a wide range of insured losses has been predicted from between $5bn and $20bn, caused record snow and low temperatures, and disrupted ageing electrical and water infrastructure.
But meteorologists have said they are unsure whether climate change was a factor in the severity of the storm. Uri was one of a line of major winter storms to have hit Texas in recent decades, with 2011 the next most recent.
“When we look at the longer-term trend, cold weather events are actually on the decrease in terms of frequency,” BMS Group vice president Andrew Siffert told Trading Risk.
Chris Allen, a senior product manager at catastrophe modelling firm RMS, said that Texas had seen three other events similar to Storm Uri in the past 150 years.
"This isn't something completely out of the blue," he said.
Siffert said that “we really don’t see a true change” in terms of storm magnitude. “There’s not enough data to say for sure,” he added.
The BMS meteorologist pointed the finger at Texan infrastructure as a driver of insured losses from Storm Uri and other events. Millions went without power and water in the state as utility systems buckled under the strain of the extreme weather.
“We’re seeing more and more losses in the insurance industry because of ageing infrastructure,” Siffert said. “Ultimately the insurance industry bears a lot of the burden.”
Experts said that there is no clear consensus on how climate change could affect winter storms in the future, with several variables that could affect storms in different ways.
For example, Arctic warming could destabilise the polar jetstream, which may lead to more frequent storms, RMS’s Allen said. But other factors might reduce the severity of snowstorms.
A 2020 study by the University of Illinois claimed that by the end of the century, there could be 28% fewer snowstorms in the central and eastern US if emissions continue at the current rate.
“Generally, what we consider an abnormally mild winter now, in terms of the number and intensity of snowstorms, will be the harshest of winters late this century,” the study’s lead author, professor Walker Ashley, said in the Nature Climate Change journal.
“There will be fewer snowstorms, less overall precipitation that falls as snow and almost a complete removal of snow events in the southern tier of the United States."