The CSIRO have published a joint research paper showing the results of research conducted into the effects of a +4ºC rise in global temperatures, finding that such an increase would lead to major reductions in annual rainfall in southern Australia, significant increases in evaporation across the country and reduced snow cover in alpine regions.


The findings, presented by CSIRO’s Climate Adaptation Flagship researcher Dr Penny Whetton, show that compared to annual average temperatures recorded in 1850, a 4ºC warming might occur by the end of this century if greenhouse gas emissions stay high.


"Rapid global warming of 4ºC would be unlike anything experienced before by modern human societies – presenting us with huge challenges in terms of our ability to adapt," Dr Whetton said


She said according to a review of recent climate models by CSIRO and Melbourne University, Australian climate changes at 4ºC or more of global warming include:

  • Temperature increases of about 3ºC to 5ºC in coastal areas and 4ºC to 6ºC in inland areas
  • Likely declines of annual rainfall in southern Australia, particularly in winter, of up to about 50% but uncertain rainfall changes in other regions
  • Marked increases of potential evaporation of about 5% to 20%
  • More droughts in southern Australia
  • Snow cover duration falling to zero in most alpine regions.


The joint paper presents figures for Australian capital cities and regional centres centred on current climate and the impact of combined temperature and rainfall change.  Since records began in 1910, the average temperature has risen nearly 1.0 ºC. 


"It is important to note that although some climate change is inevitable, changes of the magnitude described here are still avoidable as long as we are able to significantly reduce global greenhouse emissions," Dr Whetton said.


CSIRO produced national climate projections in 1990, 1992, 1996 and 2001 and, jointly with the Bureau of Meteorology (BoM), in 2007. The next set of national climate projections are planned for release in 2014, representing a significant climate science milestone timed to follow the next global assessment by the Intergovernmental Panel on Climate Change (IPCC).

"In three years, Australians will have the latest climate projections for the 21st Century for a range of factors including; sea levels, seasonal-average temperatures, rainfall, as well as extreme weather events such as heatwaves, fires, droughts, floods, and cyclones," Dr Whetton said.

"Our research will only be of value if it is clearly communicated and then rigorously applied in formulating adaptation strategies."