Archive for ‘Water’

May 31, 2011

Water and Climate Change and Adelaide…

On Monday 30th May four excellent speakers yesterday gave Adelaideans a free chance to learn more about water and climate change and even the nature of science itself. The event, part of the “4 in 40” series, took place at the Flinders Street Baptist Church, and was organised by the Water Research Centre at the University of Adelaide and the Department for Water. Under the banner “Four in Forty,” each of the ten minute presentations outlined current research and its implications.

Dr Graham Green of the Department of Water chose to focus on work done around changes in supply (run-off, ground water recharge).
He explained that small changes in climate could lead to large changes in the amount of water available for human use (there were lots of numbers, and charts and you’d best wait for the audio download rather than rely on my scrambled recollection). He explained how his team’s modelling was carefully constructed, looking at past variations in the amount of run-off and the ground-water replenishment during winter variations, showing there is indeed sensitivity to climate.
He then outlined work that had been done looking at rainfall and water availability in the Clare Valley using low and high emissions scenarios (based on humans either doing a lot or virtually nothing to control their carbon emissions). Potentially very scary times ahead, methinks…

Next up, Mark Thyer outlined the challenges in calibrating models of ecological systems, and why getting it right matters (simply put – if models give poor details, poor management decisions will result, and understanding and quantifying uncertainty will also allow scientists to figure out what is wrong with the model and fix it).
He showed how at any stage along the “inputs – processes – outputs” line error could creep in. He ran out of time before he could really explain his very Doctor Who-ish “BATEA” (Bayesian Total Error Analysis”) [7 page pdf here] , and although there was probably too much material for 10 minutes (my cerebro-spinal fluid was leaking out my ears by the end of it), I’m very grateful that he covered the ground he did. It’s important to realise that the caricature of climate models that denialists spread – that they’re simply computer models dreamed up and then left untouched – is totally false.

Next up was Brad Udall, of the University of Colorado and NOAA. He engaged the audience by asking how many knew of the concept of the Anthropocene (the word invented by Nobel laureate Paul Crutzen to describe the new geological age of human impact on the Earth). He also recommended the latest edition of the Economist, with the cover story “Welcome to the Anthropocene” (it’s the one with the 16 page slaggng off of Australian political discourse!)
He wanted us to realise that climate change is mostly about (changes to) the water cycle, and he wanted to get across the almost Buddhist notion of needing “the Right priorities, the right science and the right management.”
He got the first big laugh of the day by showing a cartoon of a scientist pointing at a pie chart and saying “the trouble is 56% can’t do the math and 54% won’t do the math.”
He pointed out that climate change will affect water cycles in “scary ways” and contrasted the 20th century water management (“demand has increased, we’d better go and get more supply”) with 21st century management, which would need to be much cleverer and iterative.
He threw in a very useable quote by one T Morris Longstreth quote “Of course we weren’t lost. We were merely where we shouldn’t have been without knowing where that was.” [see pdf of Udall’s here]
He also recommended a Policy Forum 2008 article “Stationarity is Dead.”
He (controversially) gave Australia an “A” for its water management, contrasting it with America (an F). The correct priorities, he said were a) the Environment, b) Critical Human Needs and c) Agriculture. The American system, he expounded during the questions, was based on a “first in line first in rights” system dating back to the 1850s, and not fit for purpose.

On the question of science he was at pains to pint out that models are not crystal balls, and that they don’t give policy makers the sorts of answers they are looking for (models don’t get variability right, or scales etc), and that there is a lure of false certainty to be resisted.
He cited the aphorism “model for insights, not outcomes” and President Eisenhower’s line “Plans are worthless, planning is everything.”
In the future, Prof Udall said “Group learning is mandatory.”
The right management, he felt, would have to be aimed at discovering robust, resilient and adaptive solutions. More important than “averages”, which hide more than they reveal, he felt that Probability Distribution Functions – giving ranges of likely outcomes – were crucial.
He warned also that “robust will not be cheap” and dismissed 2050 targets were any use, since reality will be “a moving target.”

Udall’s was a hard presentation to follow, but John Tibby acquitted himself very well. He was presenting Dr Jennie Fluin’s work on “A paleo perspective on the history of the Lower Murray and its relationship to past climate.”
He presented his conclusion first (since he was sure he’d run out of time) and it was that “Under climate ‘boundary conditions’ similar to present there have been periods of low flow longer than experienced [in the last 170 years].”
He then launched into a fascinating account of how scientists can be confident of that scientist, involving different diatoms that thrive in conditions of different salinity and pH and flow. There’s evidence for sustained periods of both higher and lower flow in the past….

There was time for some questions. I asked Graham Green about which emissions scenarios they’d used (B1 and A2, as per the wider work they were fitting into; he kindly explained afterwards why that was the case, pointing out that as far as the short-term [2030] goes, there’s not much difference between the A1F family and A2), and asked all the panellists if, since there is growing uncertainty in the modelling, should scientists be flagging to policy-makers that there’s a more-than-negligible chance of rapid/severe change.
Graham Green felt that it was up to the end users to decide what level of uncertainty they were tolerating, but mentioned that if the risk profile is such that you can’t change rapidly [desalination plants don’t get built overnight, as Mark Thyer pointed out in his answer to the same question] then policy makers may need to bet high. Mark Thyer broadly concurred, and pointed out that it was important to make sure systems were resilient, but that this wasn’t easy to do.

Brad Udall was then questioned on his rosy assessment of Australia’s response. He admitted that after being here for 2 months he was able to see warts, but asserted that relative to water reform worldwide, Australia was ahead of the game. He used the lovely aphorism “I’d rather be upstream with a ditch and a shovel than downstream with a decree.” Adelaide is downstream…

There was a further question on the modelling and the amount of sensitivity to variability.
Mark Thyer confessed that a lot of the end-users are still – understandably – very keen simply to be told what number to put into their models but that he nonetheless does not advocate a single number approach, but rather putting a range of scenarios (or inputs) into the models of the system to be tested to see how it will react to future changes…. Brad Udall pitched in, reiterating that the Anthropocene changes some of the base expectations, and advocating “get a lot of very smart people in a room and don’t assume anyone has the answers”.

The final question was on the ethical implications of this research, and the likelihood of massive die-off of humans, especially in poorer countries. You could see the panelists play “pass the parcel” until Brad Udall offered some observations that scientists are wary of entering such terrain, though some have (he gave the example of James Hansen), since it come with the risk of tarnishing a reputation for ‘objectivity’.

The session then concluded with tea and coffee and biscuits and the traditional flurry of exchanged business cards.

Kudos to the hosts, and the panelists – most informative…

Other links
Water Connect – The WaterConnect website is your link to the latest information about South Australia’s water resources and water activities. WaterConnect offers you direct access to water-related data, applications and publications.
Goyder Institute – The Goyder Institute supports water resource policy and management in South Australia through scientific research.

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