17 June 2011 – The federal government has released details of expected climate change impacts for Australia’s states and territories in a report, Climate Change Potential Impacts and Costs.

Following are highlights from the report.

The Australian Capital Territory:

  • Water supply threatened through reduced rainfall and runoff into the Cotter and Googong catchments.
  • Annual rainfall could decline by up to 10 per cent by 2030 and 25 per cent by 2070, relative to 1990. Decreases in annual runoff are also projected in the ACT region of up to 20 per cent by 2030 and 50 per cent by 2070.
  • Rising temperatures and a greater number of extreme hot days. Annual average number of days over 35°C in Canberra could increase from five days currently to up to 26 days by 2070 without global action to reduce emissions.
  • Agriculture is particularly sensitive to changes in temperature and the availability of water. These projected changes could directly affect the productivity of the ACT region’s agricultural industries including its regional wine industry.

The Northern Territory:

  • Rising sea levels will impact on Kakadu National Park, given its wetland system is contingent on a delicately balanced interaction between its freshwater and marine environments. Fundamental changes in ecological function of the national park will place severe pressure on many species of both plants and animals.
  • Beef production could be reduced by about 20 per cent by 2030 and over 30 per cent by 2050. Climate change may also exacerbate the impacts of heat stress and cattle ticks on beef production.
  • Tropical cyclones may be more intense categories, but there could be a decrease in the total number of cyclones. For example, the number of category three to five cyclones is projected to increase, and by 2030 there may be a 60 per cent increase in intensity of the most severe storms, and a 140 per cent increase by 2070.

NSW:

  • Housing – Between 43,900 and 65,300 residential buildings, with a current value of between $14 billion and $20 billion may be at risk of inundation from a sea level rise of 1.1 metres. (see our article on this )
  • Extreme heat days in Sydney of over 35°C are likely to increase from 3.5 days per year currently experienced to up to 12 days by 2070 without global action to reduce emissions.
  • Extreme fire danger days in the Sydney region could rise from the current nine days per year to as many as 15 in 2050. Research suggests that by 2020 fire seasons will start earlier and end slightly later, while being generally more intense throughout their length, with these changes becoming more pronounced by 2050.
  • Dengue fever could move south to become established throughout northern NSW under moderately warmer and wetter climate conditions
  • Snow season may decrease by 96 per cent by 2050, under an extreme emissions scenario with increased warming and decreased rainfall. Species such as the mountain pygmy possum will have nowhere to retreat as the climate warms.
  • Lord Howe Island could be affected by increasing altitude of the cloud layer through rising sea surface temperatures, constituting a major climate related threat to the plant communities.

Queensland

  • Extreme heat – Without mitigation, climate change is projected to cause an increase in the number of days in Brisbane above 35°C from one per year to up to 21 per year by 2100. With no mitigation, total temperature-related deaths may reach 5878 by 2100 compared to 1747 in a world with no human-induced climate change.
  • Coral bleaching – Rising sea surface temperatures could result in more frequent and widespread coral bleaching events. This is likely to diminish the ability of corals to recover and adapt, seriously threatening the Great Barrier Reef ecosystems.
  • Forests – Cloud forests and other highland rainforest types are predicted to become greatly reduced in area and more fragmented across the wet tropics even under a moderate climate scenario of 1°C temperature increase and a small reduction in rainfall. A 2°C rise in average temperatures could force all endemic Australian tropical rainforest vertebrates (such as ring-tail possums, tree kangaroos and many insects) to extinction.

South Australia

  • Wine – Rising temperatures are likely to have a major influence on wine grapes bringing the harvest forward by a month and yielding lower quality grapes which would eventually affect grape prices.
  • Drought – Declines in rainfall will lead to a greater frequency and/or severity of drought, with decreased flows in water supply catchments.  However, research also shows that despite a drier average, there may also be an increase in flood risk due to an increase in extreme rainfall events.
  • Land-based species and ecosystems restricted to Kangaroo Island and the Mount Lofty Ranges are likely to be among the most vulnerable to climate change. Coastal ecosystems will also be vulnerable to sea level rise, storm surges and reduced rainfall. Ecosystem change is also likely to impact on internationally significant migratory bird species.

Tasmania

  • Subalpine areas – a change in fire regimes may affect fire-sensitive conifer species including huon pine and cause a significant decline in their populations. Endemic fish species in the highlands of Tasmania are also vulnerable to extinction under higher temperatures.
  • Sealife – An increase in sea surface temperature and strengthening of the East Australian current will drive many plankton, seagrass and mangrove species southwards and significant declines in marine kelp forests around Tasmania have already been attributed to warmer sea temperatures.
  • Salmon – A temperature rise of 3°C may result in severe stress to Tasmanian salmon. Warmer temperatures are also likely to increase outbreaks of disease in aquaculture operations and changes to rainfall and changes in salinity, nutrients and sediments may also have a negative impact.
  • Tasmanian rock lobster – fishery, with an estimated value of $72 million (at the first point of landing) in 2009, is also vulnerable to climate change. Warmer water and changing ocean currents are expected to impact on lobster fisheries and allow the spread of sea urchins that damage lobster habitat.

Victoria

  • Murray Darling Basin – Much of Victoria lies within the Murray Darling Basin region where climate change is likely to have serious impacts on water resources. Projections indicate a 13 per cent reduction in average surface water availability in the south of the Murray Darling Basin as a median outcome by 2030. The reduction would be greatest in the south-east where the majority of runoff is generated and where the impacts of climate change are expected to be greatest.
  • Water catchments – In Melbourne the average long-term stream flow into water supply catchments could be reduced by up to 11 per cent by 2020, and as much as 35 per cent by 2050.
  • Extreme temperature – The average annual number of days above 35°C is likely to increase from nine days currently experienced in Melbourne to up to 26 days by 2070 without global action to reduce emissions.
  • Snow – A reduced snow cover of 10 to 40 per cent relative to 1990 by 2020 is projected. Fire Penguins – Increased occurrence of hot, dry and dusty weather is projected for the future and may result in increased fire-related risk of Little Penguin death and injury on Phillip Island.
  • Wheat – While wheat producers may benefit from carbon dioxide fertilisation with modest levels of warming, yields are likely to decline under more extreme warming scenarios. For example, in the region of Birchip, yields may drop by more than 20 per cent by 2100 in the absence of mitigation.

Western Australia

  • Extreme heat – Projections indicate that the annual average number of days above 35°C in Perth could increase from the 28 currently experienced to up to 67 days by 2070 without global action to reduce emissions. A hotter, drier climate would inflict a high economic impact on water supply infrastructure across the country, with Perth likely to be the most severely impacted city in Australia through climate change induced water scarcity
  • Species – Climate change is likely to have severe impacts on endemic species in the south-west, including native fish which are vulnerable under higher temperatures.
  • Agriculture is WA’s second major export industry. The state’s vast area provides soils and climates suited to a variety of agricultural production from rangeland grazing and broad acre cereal cropping to irrigated pastures and horticulture, orchards and vineyards. Wheat, wool, beef and lamb are its main products.
  • Wheat and sheep– By 2070, south-west WA is likely to experience yield reductions in wheat. Cropping may become non-viable at the dry margins with strong warming and significant reductions in rainfall. Projections indicate that wheat production could decline by 8 per cent by 2030 and 12 per cent by 2050, with similar declines for sheep meat.

Minister for Climate Change and Energy Efficiency, Greg Combet  said: “We can avoid the worst of these impacts if we take action now to tackle climate change including by introducing a carbon price,” he said.

“For the impacts which scientists advise are unavoidable it is important to start considering ways of managing and adapting to these changes.”

See the full report here