Key findings from the South Eastern Australian Climate Initiative — ASN Events

Key findings from the South Eastern Australian Climate Initiative (7755)

David Post 1 , Bertrand Timbal 2 , Francis Chiew 1 , Harry Hendon 2
  1. CSIRO, Canberra, ACT, Australia
  2. Bureau of Meteorology, Melbourne, Vic, Australia

From 2006 to 2012, SEACI – led by CSIRO’s Water for a Healthy Country Flagship and the Bureau of Meteorology delivered research which answers key science questions about the causes and predictability of climate variability and change and the impacts on water availability across south-eastern Australia, inclusive of one of Australia’s most productive and populated regions – the Murray–Darling Basin. By placing these extreme events into historical context and developing improved seasonal predictions and long term projections of future climate and water availability, SEACI has enabled better management of the impacts of climate variability and change.

SEACI research outputs have improved projections of the future climate of south eastern Australia. The climate models analysed predict a reduction in winter rainfall for south-eastern Australia, translating to a considerable reduction in both winter and annual runoff. If the global average temperature increases by 1 °C, average annual rainfall is expected to decline by between 0 and 9 percent, and average annual runoff is expected to decline by between 2 and 22 percent for the southern section of the SEACI region (south of 33° latitude).

Another key implication of SEACI research is that the cool or ‘filling’ season, where most of the runoff for water supply systems is produced, may be less reliable in the future. Also, in the light of expansion of tropical influences, this may be offset to some extent by increased rainfall in spring and summer, depending on the state of the Pacific, Indian and Southern Oceans. SEACI research also demonstrated changes to surface water and groundwater connectivity during the Millennium drought, particularly in low relief catchments.

SEACI research also contributed to improvements in the seasonal forecasting of rainfall and streamflow across south-eastern Australia. These improved forecasts will assist resource managers and users in adapting to a variable and changing climate. The Australian Bureau of Meteorology has adopted these forecasts for operational use.