Climate change is fuelling more intense and damaging storms in Australia, our new report has found.
The Super-Charged Storms in Australia report finds Australia is highly vulnerable to increasingly intense storms, including storm surges associated with tropical cyclones and east coast lows.
The annual frequency of potential severe thunderstorm days is likely to rise by 30% for Sydney, 22% for Melbourne and 14% for Brisbane by the end of the century.
1. Climate change is fuelling more intense and damaging storms.
- Extreme weather events including tropical cyclones, extreme rainfall, hail/thunderstorms and extra-tropical cyclones (for example, east coast lows) are now occurring in an atmosphere that is packing more energy and carrying more moisture than it did in the 1950s.
- Climate change exacerbates coastal flooding from storm surges both from intensifying coastal storms and from higher sea levels. The risk of coastal flooding from storms has increased significantly as sea levels have risen about 20cm since the mid-19th century and are projected to increase 0.3-1.0m by 2100 compared to 2000 levels.
2. The recent storms in South Australia and New South Wales have been influenced by climate change.
- One of the most intense storms to impact SA in 50 years hit in September 2016. This storm resulted in 80,000 lightning strikes, golf-ball sized hailstones and left 1.7 million people without power. All extreme weather events including the SA storms are occurring in an atmosphere that is warmer and contains more moisture.
- The June 2016 extra-tropical cyclone (east coast low) brought intense rainfall and coastal flooding to the NSW east coast including Sydney. The associated storm surge caused extensive coastal erosion, flooding and consequent loss of property and housing. The damage caused by the storm surge was exacerbated by sea-level rise as a result of climate change.
3. Climate change will continue to exacerbate storms in Australia, increasing the risk of devastating impacts.
- Australia is highly vulnerable to more storms of increasing intensity, especially storm surges associated with tropical cyclones and extra- tropical cyclones, including east coast lows, that are likely to become more intense.
- Australia’s infrastructure has been built for the climate of the 20th century and is unprepared for more intense coastal storms and rising sea level.
- Extreme rainfall events are projected to increase in intensity across most of the continent, but the trend may be less prominent in southwest Western Australia, where large reductions in mean rainfall are projected.
- Tropical cyclones are projected to become less frequent but more intense, with stronger winds, higher rainfall and more severe storm surges.
- East coast lows are expected to decrease in number by about 30% towards the end of the century, but the intensity of the most severe east coast lows could increase.
- The annual frequency of severe thunderstorm days is likely to rise by 14% for Brisbane, 22% for Melbourne and 30% for Sydney by 2100.
4. Without strong action on climate change, storms and other extreme weather events will continue to become more intense and more damaging.
- Australia must do its fair share of meeting the global emissions reduction challenge by cutting its emissions rapidly and deeply to help stabilise the world’s climate and reduce the risk of more extreme storm events.
- Australia’s very weak target of a 26-28% reduction in emissions by 2030 compared to 2005 levels – and we are on track to miss even this target – leaves Australia lagging well behind other OECD countries.