The amount of water available in the Murray-Darling Basin has almost halved in two decades, with fears it is set to reduce even further as a result of climate change, according to a new report.
Compiled by the Climate Council, the report entitled Deluge and Drought: Australia’s Water Security in a Changing Climate warns of worsening droughts, reduced water security and increased climate volatility as a result of climate change.
If left unchecked, the report states that the effects will have a grave impact on agriculture, with the current drought covering much of Queensland, NSW, east Gippsland and northern Victoria among the weather events being influenced by climate change.
A former Bureau of Meteorology head and one of the seven co-authors of the report, Professor Rob Vertessy, said Australia faced some significant water security challenges as a result of climate change, while Climate Council’s Professor Will Steffen fears stream flows will be impacted.
‘‘We’re very concerned that streamflow in the basin will reduce even further, affecting everybody who depends on the river as well as fish and bird life,’’ Prof Steffen said.
‘‘Climate change is shifting our rainfall patterns and increasing the severity of droughts and floods ... things are getting worse ... Climate change means severe droughts are expected to become more frequent, increasing the risk of water shortages for agriculture and urban water supplies.’’
The report said climate change had had a worsening effect on droughts.
‘‘Since the mid-20th century, the severity of droughts, such as the millennium drought, has also been increased by climate change,’’ the report stated.
‘‘Across the Murray-Darling Basin, streamflows have declined by 41 per cent since the mid-1990s. The intensity of the rainfall deficiencies in the MDB (Murray-Darling Basin) over the last two years is comparable with the worst two-year period experienced during the millennium drought (2006 to 2007).’’
According to the report, agricultural yields in the Murray-Darling Basin were 18 to 22 per cent below average between 2002 and 2009, while April and May rain reduced by a quarter, with autumn breaks coming later in the year or not at all.
Federal Finance Minister Mathias Cormann last week hit back at suggestions the Federal Government needs to do more about climate change.
‘‘We are dealing with climate change,’’ Senator Cormann said last Tuesday.
‘‘My view and our view is that we have to continue to take strong and effective action in relation to climate change but in a way that is economically responsible.’’
However, Farmers for Climate Action has called for immediate action to address and respond to the long-term challenges of climate change and ensure agriculture is protected.