Australia
March 17, 2006
It’s hardly a new message that
CSIRO Sustainable Ecosystems climate researcher Mark Howden
delivered to a recent Grains
Research and Development Corporation (GRDC) Update for
Advisers, but it was highly relevant.
Dr Howden’s message was that Australia’s graingrowers will have
to “change with the times” as they adapt to the expected climate
changes. But then, he said, they’ve been adapting already to the
early stages of climate change.
They’ll have to cope with more erratic, and sometimes more
intensive rainfall, El Nino conditions becoming “almost the
norm, rather than the exception”, higher temperatures, fewer
frosts and increasing carbon dioxide concentrations which will
improve crop growth but decrease grain protein.
More than 120 private and public sector advisers attended the
Dubbo Update, one of the annual round organised by the GRDC to
ensure the grains industry remains aware of the latest, locally
relevant, research results.
The NSW and Queensland DPIs, CSIRO, universities and
agribusiness collaborate with the GRDC in presenting the
Updates, while the corporation’s northern region coordinator of
Updates, John Cameron, liaises with local committees to ensure
Update speakers address issues of local research interest.
Dr Howden told his Dubbo Update audience scientists had detected
changes in rainfall patterns, sea levels, rates of glacial
retreat and biological responses consistent with expectations of
“greenhouse” climate change.
Last year was the warmest in Australia’s historical record –
1.09 degrees higher than the average between 1960 and 1990 – and
the last 10 years had been the warmest decade ever recorded
instrumentally.
The last 100 years were the warmest of the millennium, perhaps
even the last 800,000 years.
The most up to date predictions were for a further increase in
global average temperatures of 1.5 to 6 degrees by the end of
the present century, and it was hard to believe such changes
would not have implications for Australia’s cropping industries.
Dr Howden said while Australian farmers would have to be even
more adaptable, there were a number of sensible things growers
and industry could do to cope with, and even take advantage of,
climate change.
The tools and approaches for managing existing climate change
variability would be a good start, but they would need some
additional improvements and capabilities, such as taking account
of factors likeincreased atmospheric carbon dioxide
concentrations.
“Higher carbon dioxide levels make plants more water and
light-efficient, resulting in greater forage biomass or grain
production, especially in dry years, but there will also be a
tendency towards reduced plant nitrogen levels and grain
protein,” Dr Howden said.
“The direct impacts of climate changes on Australian agriculture
will be the result of the combined effect of carbon dioxide
increases, rises in temperature, changes in evaporation and
changes in rainfall averages, variability and intensity.
“It will be the integrated impacts of these changes that we will
need to adapt to, either to counter negative impacts or take
advantage of positive ones. Commonsense management choices in
these areas could be worth between $100 million and $500 million
a year to the grains industry.
“Farmers could look at their own climate records
for evidence of trends in climate and, if there are trends, then
it may be worth looking at the management implications,
particularly where the trends are consistent with climate change
projections.” |