A recent study from the University of NSW’s Sydney Institute for Climate Risk and Response indicates that millions of Australians may be at risk of facing larger and more intense hailstorms due to climate change. Key cities such as Sydney, Canberra, Melbourne, and Perth are particularly threatened, as the ongoing global warming is associated with an increase in hail size.
Dr. Tim Raupach, the study’s lead author, highlighted that simulations reveal significant growth in hail sizes impacting these urban centres. For instance, historical data suggests that 10-centimetre hailstones occurred around Melbourne once every 20 years; however, future projections suggest this could increase to once every three years. In contrast, cities like Adelaide may not experience the same level of change.
Hailstorms have historically been responsible for over 20 per cent of insured losses in Australia from 1967 to 2023, with the largest recorded hailstone measuring approximately 16 centimetres found in Mackay, Queensland. The damage caused by hail is directly related to the size of the stones; therefore, the anticipated rise in hail intensity raises concerns for properties and infrastructure.
Despite the fact that hail is made of ice, its formation relies heavily on atmospheric warmth. Strong updrafts in thunderstorms help lift moisture high into the atmosphere where it freezes, forming what are termed “hail embryos.” The sustained strength and height of these storm clouds are crucial for the development of larger hailstones.
Certain regions, particularly along the East Coast—from north of Brisbane to south of Sydney—are identified as more vulnerable to increased hail activity. This presents specific challenges, especially regarding infrastructure like solar panels, which could suffer greater damage in more frequent hailstorms. Nevertheless, Dr. Raupach cautioned that this should not deter investment in renewable energy sources.
To mitigate the risks from hail, it is advised that individuals take precautionary measures, such as seeking cover during storms, ensuring vehicles are parked in sheltered areas, and maintaining good insurance coverage. Dr. Joanna Aldridge from QBE Insurance pointed out that Australian building codes currently do not account for hail resistance, leaving many structures exposed.
The authors of the study emphasise the importance of both immediate and long-term strategies. While short-term actions may include better personal preparedness, there is also an urgent need to address broader climate issues and advance research into future hail trends. This could ultimately inform urban design to enhance resilience against upcoming storm risks.