Hailstones in Canberra are likely to get bigger and come more often, according to a new study of the impact of climate change. Researchers at the University of New South Wales ran simulations for cities in Australia, and concluded the conditions in the ACT were increasingly suitable for bigger hailstones than the ones that decimated buildings and vehicles in 2020. "We looked at changes in hailstone size between simulations of historical and future periods," Tim Raupach of the university's Institute for Climate Risk and Response said, "and we can see increases in hail size produced by the model around Sydney, Canberra, Melbourne and Perth". "Our projections also show hailstorms becoming more frequent in Brisbane, Sydney, and Canberra," Dr Raupach said. In 2020, hailstones the size of cricket balls pummeled thousands of cars, presenting insurance companies with 37,000 claims from the ACT alone. The record size of an Australian hailstone is 16cm across, more than twice the width of a cricket ball. Hailstones that size struck in Queensland in 2021. The researchers said more intense storms in the future could increase the chances of such large-diameter hailstones. Contrary to what you might expect, hailstones strike in the spring and summer. They form when warm air is pushed quickly up into cooler air in thunderstorms. When they rise high enough, they turn to ice. "The stronger the updraft, the longer a hailstone can stay in the storm and grow," Dr Raupach said. "Eventually, the hailstone gets too heavy and falls." The researchers forecast that the conditions for hailstones to stay aloft and gather more ice were going to become more frequent. While the most obvious damage in Canberra was to cars and some buildings (like the Shine Dome, where water poured in through shattered ceiling windows), the researchers warned that solar panels would also be increasingly vulnerable (because there are more of them about). "Hail can damage solar panels. We've seen it happen," Dr Raupach said. The study was done in conjunction with QBE Insurance, which has an obvious interest in finding out what future risks are. "Australian building standards still don't include hail resilience, which leaves many properties vulnerable," study co-author Joanna Aldridge from the insurance company said.