How dry I am: Droughts and desalination, another amplifying feedback

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"How dry I am: Droughts and desalination, another amplifying feedback"

drought-little.jpgOur never-ending quest to identify all the amplifying climate feedbacks takes us back to Australia:

THE worst drought in a century, especially in Australia’s most populated and fastest growing regions, has forced state governments to make expensive, and in some quarters unpopular, decisions to secure water supply.

As rainfall dwindles, new dams are a less-than-promising prospect, so governments have looked to the boundless resource surrounding us — the sea — for an answer. Their solution: desalination….

The Bureau of Meteorology, in its annual climate statement for 2007, “warns of a drying trend in the decades ahead.” I noted last year that one Australian newspaper reported

… drought will become a redundant term as Australia plans for a permanently drier future, according to the nation’s urban water industries chief…. “The urban water industry has decided the inflows of the past will never return,” Water Services Association of Australia executive director Ross Young said.

People, however, need water. And even though many Australian kids now “use timers to take two minute showers, and collect the water in buckets so it can be re-used in the garden”(see “What climate change drives behavior change“), conservation is not enough for some:

Four states — Western Australia, Queensland, South Australia and NSW — either have working desalination plants or are planning to build them. Opponents say that producing the large amount of electricity required to run a desalination plant hastens climate change, which may be the culprit behind Australia’s drying trend. The scientific jury is still out.

Actually, I don’t think you’ll actually find very many climate scientists who believe the jury is out on whether human-caused climate change is a major contributor to Australia’s drying trend — since the expansion of the subtropical deserts is in fact a major prediction of climate change (see here, page 10-11).

THE FEEDBACK: Greenhouse gases cause climate change that increases drought and water shortages, which in turn drives countries to desalination, which in turn generates more greenhouse gases — a classic amplifying feedback. A classic amplifying feedback unless, of course, you do the desalination with renewable power:

Some governments have countered or appeased those arguments by building wind farms to offset the power needs of their desalination plants. In Queensland, Premier Anna Bligh has challenged energy companies to come up with the best way to power a planned desal plant at Tugun on the Gold Coast using only renewable sources.

She said recently: “I want industry to come to us with their best ideas — it could be solar or wind-generated power for example, it could be carbon offsetting, or it could be a combination. Making the plant carbon neutral will save 207,000 tonnes of greenhouse gas emissions every year — which is equivalent to emissions from 46,000 cars.”

Western Australia was first off the mark with a large-scale plant. Its Kwinana plant opened in November 2007. Now it provides about 45 gigalitres of water per year, about 17 per cent of Perth’ s needs. It is powered by a wind farm at Emu Downs, although the Australian Competition and Consumer Commission recently found that statements by the Perth Water Corporation that the plant was carbon neutral were misleading, and told it not to make similar claims in the future. The corporation is now calling for tenders for a new plant at Binningup, 155km south of Perth.

Gosh, claims of carbon neutrality that were misleading — who ever would have guessed? (see “CCX sells rip-offsets: “It seemed a little suspicious that we could get money for doing nothing”“)

Victoria is building a plant at Wonthaggi in Gippsland which will supply about 150 billion litres a year, roughly one third of Melbourne’s water. The Victorian Government says it has already included the price of using renewable energy into the cost of the project.

Sydney’s desalination plant is being built at Kurnell on Botany Bay. The state government hopes to have it pumping 90 gigalitres of potable water per year from late 2009. To offset the power needs the state is building, with a private partner, a wind farm at Bungendore, east of Canberra. The 63-turbine farm is projected to have a capacity of 132 megawatts, about eight times greater than NSW’s existing installed and accredited wind power.

Stung by public criticism of the plant’s power needs, the state government says that renewable energy certificates earned from the wind farm will provide clear public evidence that the desalination plant is powered by 100 per cent renewable energy.

Running desalination plants on wind power is a start. But the future is using concentrated solar thermal power (CSP) for desal, see for instance, here and here. Given that Australia is one of the leaders in solar baseload, I suspect this will be their strategy once CSP becomes standardized over the next few years — assuming people figure out what to do with the “super-salty brine” left over from desal:

Not everyone is happy with desalination. Community groups have sprung up in each state where a plant is planned to oppose them on environmental and finance grounds.

In South Australia, the Save Our Gulf Coalition says the planned plant at Port Stanvac presents many problems. Coalition chairman Peter Laffan says for one, the site is a contaminated former oil refinery.

“Our chief concern is the brine in the Gulf St Vincent because it is very slow moving water and we have unusual phenomena in dodge tides; every two weeks there is no tidal movements for a day or so.”

That, together with the fact that flushing takes three to six months, means there is a significant threat that the brine will not disperse. Laffan says brine builds up in low-oxygen slugs that can create “dead” zones.

That’s all we need — more hot, acidic, and now salty coastal dead zones in a globally warmed future (see “The Dead Zone“). Such are the pitfalls of adaptation/desalination.

Maybe we should focus harder on prevention — after all, it’s going to take all the wind and solar (and other forms of carbon free energy) we can imagine just to avert mass desertification in the first place (see “Is 450 ppm (or less) politically possible? Part 2: The Solution“).

Other amplifying feedbacks:

Drought-related Posts:

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14 Responses to How dry I am: Droughts and desalination, another amplifying feedback

  1. Sam says:

    the expansion of the subtropical deserts is in fact a major prediction of climate change (see here).

    The above link seems to be wrong. Doesn’t take you to a page that supports your claim.

    [JR: It was supposed to be the link to the Hansen paper. I have now put in a link to the draft. The bottom of page 10 has a paragraph with the relevant studies.]

  2. vakibs says:

    Scarcity of fresh water is the most serious problem affecting mankind, not climate change. Climate change only makes it worse.

    When you don’t have enough fresh water, it immediately means you don’t have enough food. Water scarcity implies hunger, not thirst. This is one of the dangerous misconceptions amongst people.

    Agriculture is the most important consumer of fresh water. And when fresh water becomes scarce, cultivators will be forced to claim greener pastures (forest lands). Food and water scarcity is a dangerous threat to the biodiversity of the planet – much more than climate change is.

    Most of the deforestation that is happening in Amazon or Indonesia is due to subsistence farmers. Their numbers will rise rapidly in the case of famine or food scarcity. In fact, subsistence farming is a direct threat to wildlife all over the planet – in Africa, India and so on.

    The most serious effects of climate change are not rising sea levels (as scary as they might seem), but increasing drought due to melting glaciers and erratic monsoon patterns.

    Growing human population makes it only worse. We have a crisis of the highest order at our door steps. We need to diffuse this crisis right now !

    The only way out is water desalination to increase the availability of fresh water. Unlike what is claimed in this post, the energy required for desalination can come from carbon-neutral sources, such as wind, solar or nuclear power.

    Most importantly, nuclear power has a direct impact on desalination because it is cheap (nuclear plants have a history of being profitable, even if they use 50% of their capacity for desalination).

    Australia, particularly, has a lot to gain from nuclear / solar desalination as it has huge swathes of desert land which are only growing bigger (It also has some of the largest reserves of Uranium).

    Ofcourse, none of these solutions are valid in the long term. The only possible solution in the long term is to reduce human populations. This is predicted to happen in the next 300 to 400 years (with increased urbanization). Until then, we need to look for methods such as water desalination to avoid calamities.

  3. TomG says:

    They just dump the brine back into the ocean?
    That surprises me.
    I believe in Israel they “mine” the Dead Sea by pumping the Sea’s water into evaporating ponds and once the water is gone, the remaining minerals are collected. The problem is they’ve been too aggressive and have lowered the Sea to a critically low level.
    Perhaps the volumes in Australia are too high for the Aussies to “mine” the brine.

  4. Richard says:

    Meanwhile, a new study suggests that Victoria (Australia’s smallest state, with 5.2 million people, mostly in Melbourne) could cut its CO2 emissions by 54 percent over the next 12 years by changing behaviors, and utilizing energy efficiency and renewable energy.

  5. john says:

    Vakibs;

    I’m not sure what is to be gained by claiming one problem is worse than another – particularly when they are inexorably linked, as fresh water and climate change are.

    My own perspective is that if climate change were not an issue, fresh water would not be one either. We could use a combination of efficiency and desalinization to meet it with limited consequences. The surface of the earth 70% water, after all. Moreover, much of the shortage is caused by — or soon will be caused by — global warming. Desertification and loss of alpine glaciers will do more to shape our future shortages than demographics alone.

    so, if we must “rank” our problems, global warming seems to me to be the central issue we must solve, or all others — including water shortages — will get worse.

  6. David B. Benson says:

    vakibs — Tropical forest deforestation is largely due to logging, legal or not. Then the ranchers move in for a few years, at least in the Amazon. The subsistence farmers only get it when it won’t support cattle any longer.

  7. paulm says:

    We’re missing the point here trying to implement technology to maintain our consumption. It just is not going to work. eg Switch to desal to solve water shortage kill off – marine life.

    Were running out of natural water because of climate change and because were at a threshold – over consumption and over population.

    Theres a fundamental equation that we are not going to beat – the earths resources are finite and unless we live in a sustainable manner were cooked.

  8. paulm says:

    And heres an article that addresses the point….

    A climate change conversion
    We cannot tackle global warming by technology alone: we will need ethics, as individuals and as a society

    Can the climate change crisis be answered purely by science and technology, or does it need to be understood as a moral and spiritual issue too?….

  9. JCH says:

    Fewer people will work. No new technology required. Cheap.

  10. jorleh says:

    There is 90% of the world´s fresh water just around the corner in Australia. Antarctica.

    The Aussis must be some kind of idiots if they don´t know this fact. And the potential energy of the Antarctic ice masses to generate millions of TWh´s of energy for them. Easily. And for all of us.

  11. vakibs says:

    @paulm

    We are already in a cooked situation, due to over consumption and over population – what we need to do is damage control. Unless we have water desalination projects, there will be terrible implications for humanity and the rest of life forms on this planet.

    Human population is projected to stabilize by 2050 and decrease gradually from then on. We need to have a strategy to maintain the biodiversity equilibrium of this planet, during this transition period.

    @john

    Water scarcity is happening at this very moment. The primary cause is overpopulation, which is abusing surface water and drilling out geological water acquifiers. Melting glaciers and changing rainfall patterns are a secondary cause.

    The problem of fresh water scarcity has to be tackled head on. Human history is replete with civilizatioins being uprooted due to lack of water. We need to avoid this catastrophe, otherwise the consequences of warfare and famine will be manifest not just on mankind, but also on animal and plant life.

    It is easy to blame loggers for deforestation, but they are only part of it. There is increased pressure on forest land due to overpopulation, particularly amongst traditional tribal communities which have long practiced slash and burn agriculture. This will only worsen in the face of water shortage. Cattle ranches on forest land is another terrible story, the meat goes for the consumption of urban people. This is one area that has to be severely monitored – the transportation of meat products, if only for the sake of health.

  12. David B. Benson says:

    vakibs — Slash and burn is not much of a problem, IMO, nor are water shortages predicted for (most of) the Amazon rain forest nor in Southeast Asia, just the Congo rain forest. In any case, slash and burn is slowly being replaced by the sustainable practice of slash and char.

    In South America and Indonesia, loggers are the first and worst. Those coming later mean the forest has no chance to recover.