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Climate change is now an issue for planners
Climate change is set to become a dominant issue in planning Western Australia's medium and long-term future. Recently its importance has been underlined by two major reports and a series of commentaries by organisations like the CSIRO.
Together they have described Australia as "vulnerable" and pinpointed areas like WA's fast-growing Southwest Region as places where significant impacts from global warming can be expected. One of the reports, by the WA Greenhouse Task Force, has also offered a strategy of responses - including proposals for a more integrated approach to urban planning.
Both the federal report, "Climate Change: An Australian Guide to the Science and Potential Impacts" and statements by the CSIRO have drawn attention to the challenges faced by WA.
The federal report lists Western Australia's main vulnerabilities as:
- Water supply in the Southwest;
- Tropical cyclones and floods affecting industry and settlements in the North;
- The wheat harvest; and
- Loss of biodiversity in the Southwest.
According to Dr Barrie Pittock, of CSIRO's Atmospheric Research, such events pose a "significant threat" to Australia's natural resources. He told a Queensland conference on climate change that the decrease in rainfall in WA's Southwest together with similar reductions on the southeast mainland would lead to a further drying out across the country between now and 2070.
"These changes in climate will lead to increased drought, greater fire danger and more soil erosion, as well as more floods and more intense tropical cyclones in some areas," Dr Pittock said.
Although the federal and State reports were prepared separately, the WA report does provide a response to some of the problems outlined in the federal report. For example, WA's draft "Greenhouse Strategy" sets targets for cutting the level of greenhouse gas generated by transport which is currently responsible for about 14% of total emissions.
The State strategy would aim to cut this level by 20% by 2020 through a combination of travel demand management programs, traffic management strategies, infrastructure investment and the promotion of fuel-efficiency and cleaner fuels.
The draft strategy also recommends a "more complete integration of urban planning and transport planning" and emphasises the need for freight planning.
Meanwhile in a media statement to launch the federal report, Dr David Kemp, the Federal Minister for Environment and Heritage, points out that Australia's vulnerability to climate change is intensified by the fact that the country is already generally dry and experiences high natural climate variability from year to year.
The federal report says that on top of regions with specific problems to combat, climate change will also increase the Australia-wide risk of invasions by "exotic pests, weeds and diseases". It says the country could also see "population pressure from neighbouring territories rendered less viable by rising sea levels."
The federal report builds a picture of how Australia's climate is already changing. It says that in the last century Australia's average temperature has increased 0.7° C and that in the last 50 years rainfall has increased over the Northwest and reduced in the Southwest and much of Australia's southeast.
"Effects on runoff are potentially serious as evidenced by a 50% drop in water supply to the reservoirs supplying Perth since the 1970s and near-record low water levels in storages in much of south-eastern Australia in 2002-03 due to low rainfall and high temperatures in the south-east since 1996," says the report.
The federal report say climatic modelling suggests that annual average temperatures across Australia could increase by 0.4° C to 2.0° C by 2030 and by 1.0° C to 6.0° C by 2070 - relative to 1990. At the same time the model suggests annual rainfall in the Southwest could be down by 20% by 2030 - or up by 5%.
It will not be just agriculture that is impacted. "Settlements, industry and infrastructure will be vulnerable to adverse effects of extreme weather events, and particularly to increased heat stress on people and materials," said the report.
The report also suggests the likely costs of change have been underestimated.
"Costs due to impacts and costs of adaptations will increase with increasing global warming," it says.
"They will increase even more rapidly as various critical thresholds are reached, such as changes from profit to loss in particular farming enterprises, or riverine and coastal flooding exceeding present planning limits.
"Potential costs and benefits of climate change need to be balanced against costs and benefits of mitigation in any overall policy response."
Western Australia has now suggested what some of its major responses could be in a draft of the State Government's proposed "Greenhouse Strategy". Public comment is being sought by March 15 on proposals for:
- Reducing emissions;
- Promoting sequestration;
- Ensuring effective adaptation to changed climate conditions; and
- Pursuing economic opportunities that arise from climate change.
The reduction in emissions includes a 12% cut by 2006-07 in those produced by government agencies. With agencies currently generating more than 524,000 tonnes of greenhouse gases annually, such a reduction would be the equivalent to taking 12,000 cars off the road, according to the government's latest audit.
