Water Journal : Water Journal June 2015
JUNE 2015 WATER 37 Feature Article say we could see as much as 34 per cent less rainfall and more evaporation by 2030. Richard Davis, former Chief Science Advisor to the recently disbanded National Water Commission, says climate change was not considered when the current SDLs for the Basin were set three years ago. “The Authority was quite clear. They did not incorporate climate change into their hydrologic modelling (for the Sustainable Diversion Limits).” He says this was despite the CSIRO incorporating climate modelling into its Sustainable Yields Study for the Murray-Darling Basin in 2007–2008. “I was actually very surprised (when the Authority didn’t). I assumed that these days it’s widely regarded that it’s one of the fundamental drivers for your modelling – your longer term modelling – so you would normally include it. So I was very surprised when they didn’t. I’ve never had a satisfactory explanation for why they didn’t.” Professor Mike Young says he has an explanation. Three years ago, he says, he had discussions with the MDBA Board about how to manage for future climate change, and scientific uncertainty. “My sense at the time, talking to the board, was that they realised to make the change they’d have to go back and change or amend the act and convince the governments to do that and it was just all too hard. It was better to leave these two issues – how to deal with climate change and how to adapt in the future – to future boards and future governments.” Asked for a response, Dr Rhondda Dickson, MBDA Chief Executive, says: “That might be Professor Young’s view, that’s certainly not how the Basin Plan was built. We’ve just recently published a paper, a technical paper actually that talks about how climate change has been incorporated in the Basin Plan.” (This is the technical paper that the scientists are challenging.) Hydrologist Richard Davis says he agrees with Mike Young that three years ago the MDBA board appears to have made a political choice: “Partly because they had enough on their plates fighting the argument for returning water to the environment and they didn’t want to open another front with all the climate change sceptics. I don’t think they wanted radio shock jocks on their tail over climate change at the same time.” Colin Mues, Director of Environmental Management at the MDBA, agrees with the scientists that the SDLs are based on past climate variability of the last 114 years – and not the scientific prediction that in the future average rainfall in the Basin will decrease, with more frequent and severe droughts. Section 6.06 (c) of the Murray-Darling Basin Plan says that the Authority “must” conduct a review of the management risks to the Basin from climate change. But a date has never been set. Colin Mues has revealed to ABC RN the Authority’s proposed timeline. “My thinking is that as we approach the next review point for the Basin Plan, which is currently 2022, it gives us a good window (for a review of climate change as well),” he says. “It’s not a near-term priority, while we have Basin Plan implementation being completed, while we have environmental works and measures being put in place, while we have the understanding of climate change improving all the time. So I would see that it would be after those things are in place or we’ve got time to collect some additional information (about climate change) – that would be the best time for a review.” Professor Quentin Grafton from the Crawford School at the ANU says that climate change must be on the table in 2022 because it’s not on the table now. “Yes, it may well be the case 10 years down the road when we revisit the Basin Plan that we will account for climate change, but that’s in the future, that’s not the reality today”. WJ A note from Chris Davis, Water Journal Technical Editor: The ABC Radio National story reproduced here reveals a vigorous policy debate, precipitated by the paper by Neave et al. in our April issue. The protagonists do not seem to disagree on the science of climate change, but are divided on the proposition that the current Plan does not yet take climate change into account. In an upcoming issue of Water Journal we will be publishing a paper in response to the MDBA paper, authored by Jamie Pittock [et al.] from the Australian National University. Most scientists agree that the Murray-Darling Basin will experience longer periods of drought in future.
Water Journal May 2015
Water Journal August 2015