Hailstorms may become less frequent but more intense, and potentially more damaging, due to global warming, according to a recent study carried out in the United States.
According to research published this month in the journal Nature Climate and Atmospheric Science, the frequency of these storms could decrease by an average of 25% over the coming years, but the size of hailstones could increase by 15-75%, depending on the trajectory of greenhouse gas emissions released into the atmosphere.
To make these predictions, researchers at Northern Illinois University simulated future hailstorms using supercomputer weather models, then analysed how these storms evolve as CO2 emissions increase in the atmosphere.
The predicted reduction in the frequency of these storms is likely to be due to warmer air and increased melting. On the other hand, more vigorous thunderstorm updrafts, favoured by an increasingly warm and humid atmosphere, are likely to increase hailstone size and lead to more intense storms.
According to the experts, these hailstones could measure more than 4cm in diameter, roughly the size of a golf ball.
They also draw attention to the costs incurred by these storms. “Over the last 18 months, we’ve had over US$100 billion in losses in the United States from severe storms, and a majority of that is hail,” lead author Vittorio Gensini said.
Damage is frequently observed on private homes and public buildings (roofs torn off, electricity disconnected), as well as on vehicles. The problem is compounded by the fact that current infrastructure is not designed to withstand large hailstones.
“While not comprehensive, these works do offer insight into a process-based understanding of potential changes and are relatively inexpensive from a computational perspective,” the study authors added.
Research over longer periods, in more regions and on a larger number of climatic events is needed, however, to determine more precisely the frequency and intensity of hailstorms in years to come.
And the US is not the only country concerned by the effects of hail. In France, the period from March to July 2024 was marked by violent hailstorms that seriously damaged agricultural and wine-growing crops in several regions, where thousands of homes were left without power.