Grim warning on extreme weather for Australia

Cyclone Yasi storm waves hit Townsville. Source: Flickr/BitKeeper82

The Intergovernmental Panel on Climate Change (IPCC) has released a Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). This report brings together the latest findings on the relationship between climate change and extreme events, and their implications for societal development.

The report was prepared by 220 authors from around the world (including three Australians), and took four years to complete. It has undergone an exhaustive review process, and is an authoritative statement from the IPCC.

Key findings include:

Heat

It is 99% certain that there will be substantial increases in temperature extremes by the end of the 21st century. In Australia, there has been an increase in the number of hot days, and a decrease in the number of cold days and this trend is likely to continue, with large scale increases in days over 35°C or 40°C. Heat wave events are likely to become more frequent and persist for longer when they occur.

Precipitation

In some areas of the globe, it is likely that the frequency of heavy precipitation or the proportion of total rainfall that falls as heavy precipitation will increase. In Australia, extreme precipitation is expected to increase.

Damaged house from Cyclone Yasi. Although there may be less tropical cyclones, they are likely to be stronger and cause more damage. Photo source: Flickr/Kenski1970

Drought

Some areas of the globe will experience longer and more intense drought. In Australia, there has been a drying trend in south-eastern and south-western Australia since the mid-20th century. Dry spells are likely to get longer in southern Australia.

Fire

Extreme fire danger days are expected to rise more than 15% in south-east Australia. The window of opportunity for fuel reduction burning will shift towards winter.

Cyclones

Tropical cyclone wind speed is likely to increase but the number of cyclones may decrease or remain unchanged. That is, there may be fewer cyclones, but they are likely to be stronger and cause more damage. In Australia, there is still some uncertainty about regional trends in cyclone activity. However, the strength of cyclones is likely to increase and they may come further south.

Sea-level rise

Extreme coastal high water levels are very likely to increase as sea levels continue to rise. This can worsen the effects of erosion, inundation and storm surges.

Disaster recovery

Extreme events will affect sectors which have a stake in climate such as tourism, water security, agriculture, forestry and health. Post-disaster recovery and reconstruction can provide an opportunity for reducing risk and improving adaptive capacity. The most effective adaptation and disaster risk reduction actions offer development benefits in the short term, and a reduction in vulnerability over the long term.