The Australian
By: Asa Wahlquist, Rural writer
Australia is hotter than ever and is expected to get hotter, with huge consequences for the nation's farming industry.
CSIRO scientist Mark Howden has warned that changes in climate, even though only slight, meant the nation needed to re-think approaches to agriculture.
Dr Howden, from the CSIRO's Climate Adaptation Flagship, told the Greenhouse 2009 conference yesterday that agriculture practices could look quite different in future decades.
He believes Australian farmers have "world-leading skills both from the science side of things and also the farmer network side of things''.
He foresees a future in which those skills can be exported to other regions, including the US, Africa, southern Europe and South America, as they face a drying climate.
"We have got the skills and experience, which are highly transferable and highly valuable to other countries which haven't yet come to grips with the sort of climate that we are used to,'' Dr Howden said.
Small shifts in temperature had significant consequences, he said. The average temperature over the past decade has been between 0.7C and 0.8C above the 1961 to 1990 average.
"What that means is a cold year now is like a warm to hot year in the time of our grandparents,'' Dr Howden said. "And at the current rate of change, within nine years, the coldest year we will be experiencing will be hotter than the hottest year ever experienced by our grandparents.''
Australia's hottest year on record was 2005, with an average 22.86C, which was 1.06C above the average.
Last year was 0.41C above average. In contrast, the warmest year of the 1950s, 1959, was 0.25C above the average. Most of the 50s were below the average, with the coldest year, 1956, being 0.96C below.
"The 0.7C or 0.8C degree change that we have already seen is actually pretty significant. There is no precedent in the past for the sort of temperatures we have been experiencing.''
He said the rise in temperatures had affected specific agricultural industries such as berry growing that require a period of cold. "Berry growers are already having to adapt, to move or use different varieties or use chemical controls,'' he said.
On the other hand, wheat growers in central Queensland now had fewer worries about frosts, and could plant earlier.
He said the higher temperatures had led to increased evaporation rates, "and consequently droughts being more severe for a given amount of rainfall than they were in the past''.
The big question is whether the long drought gripping the southern part of the country is due to climate change. "The conclusion that we are coming to ... is that there is a human fingerprint in the reductions of rainfall that we are seeing,'' he said.