Australian news, and some related international items

Southern Australia to be among the worst-hit by global heating

Australia among global ‘hot spots’ as droughts worsen in warming world, The Age, By Peter Hannam, June 1, 2020 The world’s major food baskets will experience more extreme droughts than previously forecast as greenhouse gases rise, with southern Australia among the worst-hit, climate projections show.

Scientists at the Australian National University and the University of NSW made the findings after running the latest generation of climate models used by the Intergovernmental Panel on Climate Change (IPCC). Future drought changes were larger and more consistent, the researchers found.

“Australia is one of the hot spots along with the Amazon and the Mediterranean, especially,” said Anna Ukkola, a research fellow at the ARC Centre of Excellence for Climate Extremes and lead author of the paper published in Geophysical Research Letters.

For southern Australia, the shift to longer, more frequent and more intense droughts up to 2100 will be due to greater variability in rainfall rather than a reduction in average rainfall. For the Amazon, both mean rain and variability changes…….

One reason for the prediction of worse droughts is that the latest models assume the climate will respond more than previously understood to increased atmospheric levels of carbon dioxide and other greenhouse gases.

Some of the models used for CMIP6 predict changes of more than 7 degrees in global and Australian temperatures by the end of the century.

Australia’s vulnerability to big shifts in annual rainfall already challenge the country’s farming sector, while also leaving much of the country’s south more at risk of bad bushfire seasons – such as last summer’s – as forests dry out.

The CSIRO has long forecast a large reduction in stream flows in the Murray-Darling Basin, for instance, as reduced cool-season rainfall combines with higher temperatures. Such a trend appears to have already begun.

While a more moderate emissions trajectory will still produce more intense, frequent and longer lasting droughts in most of the world’s mid-latitude regions than current conditions, the shift will be less than if carbon emissions remain near the top of forecasts. ……..

June 2, 2020 - Posted by | AUSTRALIA - NATIONAL, climate change - global warming

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