A new climate is emerging in Australia, according to maps released by the Australian Export Grains Innovation Centre (AEGIC).
AEGIC analysed data from more than 8000 Bureau of Meteorology stations around the country and discovered that traditional rainfall zones have shifted 100–400km since 2000. The only expansion of the winter rainfall zone has occurred in southeast Tasmania where winter rainfall has become more reliable.
AEGIC agro-meteorologist Dr David Stephens said: “Since 2000, there has been a general increase in summer rainfall across Australia, and a corresponding decrease in winter rainfall, leading to shifts in rainfall zones extending for hundreds of kilometres.
“Rainfall between May to October over much of the heavily populated regions of southern Australia has decreased by 10-30%, while summer rain has increased by up to 40% in some areas.
“This change in climate has major implications for farming and pastoral systems as the profitability of different crop types change, disease risks change and the composition of rangeland grasses changes with stocking rates.”
Regions with a Mediterranean climate and winter dominant rainfall are contracting in a south-westerly direction and summer rainfall zones are expanding southward.
Between these regions, there is a uniform rainfall zone where summer and winter rainfall are similar. The southern boundary of this zone has shifted from southern/central New South Wales down into central Victoria and the Mallee region of south-east South Australia.
Stephens said the climate had settled into a new pattern and Australian farmers should factor this into their practice.
“Australia is going to need some of the most water-efficient farming systems in the world to mitigate the effects of a drier and warmer climate in southern Australia. Research in this area is vital because Australian crop yields have been among the most affected by climate change compared to other grain exporting nations.”
Maps Copyright © 2016 AEGIC. Reproduced with the kind permission of Australian Export Grains Innovation Centre.