Australia's largest general insurer, IAG, partnered with NCAR's C3WE to undertake a comprehensive literature review focussed upon the climate change science of severe weather and its application to the most damaging weather events experienced in Australia. Damaging weather phenomena investigated included tropical cyclones, severe convective storms - notably hail, East Coast Lows, river and flash floods, urban scale flooding, storm surges and bush fires.
The science of extremes was found to have deficiencies in some areas in terms of what general insurers like IAG, as well as the wider business community, require. Analysis of insurance data has shown that the specific meteorological phenomena from these major historical events that led to multi-million dollar impacts upon the Australian community and economy are not well represented in climate science extremes studies. In some cases the base climatology is deficient and there has been slow progress leading to improve these climatologies.
The meteorological, hydrological and oceanographic extremes that produce the greatest amount of damage are not the 99th percentile events but the 99.99th percentile or rarer events, as well as shifts in their geographical distributions across Australia.
In the case of severe convective thunderstorms there is little research that investigates the past, current and future distributions of damaging and destructive hail. For tropical cyclones changes in the relative frequency of different intensities and southward shifts in the potential areas prone to landfalling cyclones is important to inform land planning decisions and building codes. For river floods catchment rainfalls coupled with suitable antecedent conditions capable of producing floods with an AEP rarer than 0.25% are needed. For bushfire there is the need to better identify the current and near future risks of meteorological conditions capable of supporting catastrophic fires.
IAG is seeking to have these aspects of climate change science brought to the fore.