Climate change set to expand extreme weather impacts: IAG report
Insurance Australia Group (IAG), in collaboration with the National Centre for Atmospheric Research (NCAR) in Boulder, Colorado, has released a report on the impacts in Australia of extreme weather events caused by climate change on property risk.
The report, dated November 2019, warns that, as a result of climate change, severe and destructive tropical cyclones have and will continue to move south, increasing most rapidly in south-east Queensland/north-east NSW and coastal areas south of Shark Bay in Western Australia.
Launching the report last week, IAG Managing Director and CEO, Peter Harmer, said IAG is one of the only insurance groups internationally that has an in-house natural perils team made up of meteorologists, scientists, climate studies experts and engineers, dedicated to understanding climate risk and extreme weather events. He said the team had been the driving force behind the climate action plan that IAG launched last year
Other key finding of the report are:
Planning for inland penetration of tropical cyclones should be based on substantial increases in both rainfall rate and affected areas. Winds are likely to decay more slowly, so increased wind-driven rainfall ingress should be expected both at the coast and inland.
More intense storms combined with rising sea levels point to increasing storm surge impacts, and these may be very substantial in some regions.
Intense short duration rainfall is expected to increase almost everywhere in Australia, resulting in more frequent flooding in urban areas and in small river catchments.
Areas at risk of large (2.0-4.9cm in diameter) and giant (>5.0cm in diameter) hail should progressively shift southwards, with the largest increase in risk likely to be in the region inland from the Hunter River south through the central and southern New South Wales highlands and central to eastern Victoria
The multi-day impacts of east coast lows on the south-eastern seaboard of Australia are expected to increase because of wind-driven rainfall ingress, flash and riverine flooding. This effect will be compounded by rising impacts from storm surge, waves, and coastal erosion.
Bushfire risk, as measured by the trends in fire danger indices, is likely to increase in almost all locations nationally, leading to more frequent and extreme events, and longer fire seasons.
Sea level rise is expected to accelerate around the Australian coastline but at differing rates.Past assessments of sea level rise are lower than those that recent observations show.
Sea level rise will contribute substantially to escalating impacts from storm surge and the impacts on coastal natural systems, buildings and infrastructure. The greenhouse gases that are already present will cause sea level rises to continue well into the next century even if there are significant emission reductions globally through the coming decade.
The report, Severe Weather in a Changing Climate, is available here.
The ABC Radio National program, Background Briefing, interviewed members of IAG's Natural Perils Team. The ABC report is available here.