Look north for a vision of east coast future
At 1.5%, Australia trails the US (18.3%) and China (19.1%) in its contribution to global emissions.
IF WE want to know what Australia's climate will be like towards the end of the century, we could start by looking north or north-west.
A detailed study of changing temperatures and rainfall patterns by some of the nation's leading climate researchers shows many Australian towns and cities on the east coast will resemble settlements that are further north and often inland.
Sydney, however, appears to be an exception to the inland rule. The city's weather is likely to resemble the tropical warmth enjoyed today by Brisbane or Hervey Bay on the Sunshine Coast, under a middle-of-the-range estimate.
''We are trying to build up a picture of what Australia will look like if we were to reach 4 degrees of global warming,'' CSIRO researcher Penny Whetton said.
''If we were to follow the high emissions trajectory path that we are on at the moment, then it is quite possible we will be looking at those temperatures this century.''
If the world follows Australia's current plan to cut back its emissions to 5 per cent below 2000 levels by 2020, much of the 4 degree rise is likely to be locked in, according to climate scientists who will speak at an international conference in Melbourne next week.
Speakers include the German government's chief climate change adviser, Professor Hans Joachim Schellnhuber, the Australian government's adviser, Professor Ross Garnaut, and the Climate Change Minister, Greg Combet. Dr Whetton and a University of Melbourne climate researcher, Professor David Karoly, drew upon Australian climate modelling developed for the most recent report of the Intergovernmental Panel on Climate Change and combined the data with other models.
The results were cross-referenced with rainfall and temperature records from the Bureau of Meteorology, allowing a glimpse of the future for many Australian towns.
''In the mid-range case, Dubbo's climate would move up into central Queensland, and in the most favourable case it is a bit wetter and would be the equivalent of the climate today in Rockhampton,'' Dr Whetton said. ''In the hotter, drier case, it moves out to Hermannsburg near Alice Springs or Tom Price [in Western Australia].''
Under the various scenarios predicted for a warmer Australia, Melbourne's climate would resemble that enjoyed today in Gawler, South Australia, Wangaratta in Victoria or Leeton in south-west NSW.
The hotter, drier temperatures are expected to bring serious challenges to agriculture, along with wider implications for the security of Australia's food supplies.
''We can expect a fundamental change - we think of ourselves as a land of plenty but that's not necessarily going to remain the case,'' said Mark Howden, an agricultural specialist at the government's Climate Adaptation Flagship.
''Looking just at wheat, under the mid-range scenario we would be looking at exports going down from 15 or 16 million tonnes going down to something like nine by 2050. The best case scenario is that we drop a couple of million tonnes. On the worst case, we would be a net importer of wheat by 2050.''
The problem is compounded by the fact that Australia's population will grow, with projections saying it will reach about 62 million by the end of the century. Fruit and vegetables, which often rely on irrigation, are also likely to fall short of demand, Dr Howden's research finds.
''We also need to cut greenhouse emissions from agriculture as well as from other sectors, and we're starting off from quite a degraded base in terms of dry land salinity, so we are facing a really significant set of challenges,'' he said.