Climate change and the Queensland floods

A version of this feature appeared first as part of Crikey‘s daily email.

IN QUEENSLAND, many – but not all – are well into the dirty job of sifting through the acrid mud and rubble for belongings, insurance certificates and hope.

If they’re not doing it already, in the coming months many will also be hoping to find some answers to that short but ever-so-complex question, why?

Premier Anna Bligh has started the process already, calling a Royal Commission with a wide-ranging terms of reference.

Among those terms, is a request the commission make recommendations to improve the “preparation and planning for future flood threats and risks” particularly when it comes to saving lives.

Unarguably the source for the flooding experienced in Queensland and now in parts of Victoria was persistent, record-breaking, heavy rain.

In 2010 Queensland had its wettest year on record, but the spring period leading up to the flooding in the Rockhampton and Bundaberg areas and then in Brisbane, was exceptional. The state got 248 mm of rainfall – almost triple the state-wide long term average.

But Premier Bligh’s Royal Commission and media coverage appears to have given little, if any, explicit consideration of the role of climate change.

This is a strange omission, given that only three months ago the State published its latest assessment of the potential impacts of climate change.

“Climate change is also likely to affect extreme rainfall in south-east Queensland,” the report said, adding that “a projected decrease in rainfall across most of Queensland, the projected increase in rainfall intensity could result in more flooding events”.

A separate Queensland Government report into rainfall intensity, commissioned to provide advice to policy makers on inland flooding risks, also agreed that “the available scientific literature indicates this increased rainfall intensity to be in the range of 3–10 per cent per degree of global warming.”

But if these are the risks for Queensland in the future it doesn’t necessarily implicate climate change in the line-up of suspects likely to be paraded before the public in coming months.

Yet a number of climate scientists are already discussing the role of increased atmospheric greenhouse gases in the atmosphere, caused mainly by the burning of fossil fuels such as coal and oil, and how it impacts extreme weather events.

Dr David Jones, head of climate monitoring and prediction at the Bureau of Meteorology, told me there will be “a healthy scientific debate in the next few years about the point when the probability of an event was so implausibly small before climate change.”

“The signal to noise ratio is so high,’’ says Dr Jones, referring to the difficulty in picking out the climate change influence among the natural variability of weather and climate.

The general view is that this is one of the strongest La Nina we have had in modern history where we have data going back to the early 1900s. The ocean temperatures last year were the highest on record and we know the oceans around Australia are warming quite quickly and that’s the fuel for the storms and rain events. In 2010 we had the highest humidity on record and July to October was our wettest ever.

Professor Matthew England, co-director of University of New South Wales Climate Change Research Centre, is reluctant to explicitly apportion any of the flood crisis to climate change. But he stressed that “to exclude climate change would be premature”.

Earlier this week, he told Reuters news agency: “I think people will end up concluding that at least some of the intensity of the monsoon in Queensland can be attributed to climate change. The waters off Australia are the warmest ever measured and those waters provide moisture to the atmosphere for the Queensland and northern Australia monsoon.”

Professor England explained to me the waters to the north of Australia have warmed by about 0.5C over the last 50 years. Those waters are currently about 1.5C warmer than average, he said, so it’s likely that about a third of this warming is due to long-term ocean temperature increases, the remainder due to the normal La Nina cycle.

The warmth of the waters north of Australia drive our summer monsoon system via evaporation – the warmer the oceans are the greater the resulting moisture content of the atmosphere. In short, a warmer ocean north of Australia means increased monsoon rains.

Professor England added that over the next 20-30 years, it was predicted that this same ocean region would warm by a further half a degree.

Professor Will Steffen, the science adviser to the Federal Department of Climate Change, has announced he will compile a report on the floods for the Gillard-government’s multi-party climate change committee, which he is a member of.

One of Australia’s leading climate researchers, Professor Neville Nicholls, of Monash University and President of the Australian Meteorological and Oceanographic Society, told me that in terms of the impact of climate change on Queensland floods “the simple answer is that we really don’t know”.

He agrees that the core driver of the deluge was the strong La Nina system.

The question is, is [climate change] exacerbating this? I would dearly like to find the answer to that. The IPCC has been projecting for a long time that as we get more warming we will get increased heavy rainfall.

He said not enough studies had been done to have confidence about the role of climate change in single extreme weather events occurring now. But he told me:

We should not confuse low confidence to mean that this is not happening. There are good grounds for believing that the warming is already affecting climate and things like heavy rainfall.

Elsewhere, other academics have been commenting on the recent floods. Professor Ron Cox, of the UNSW School of Civil and Environmental Engineering, said

The recent flood events in Queensland are a clear indication of the need for improved planning to adapt future development for our settlements and infrastructure. With expanding settlements, extreme weather resulting in emergency situations can be expected to become more frequent with higher temperatures and climate change.

Dr Caroline Sullivan, Associate Professor of Environmental Economics and Policy at Southern Cross University, has said climate scientists around the world agree that “extreme events are a likely outcome arising from climate change”.

There is currently so much evidence from across the world that global weather patterns are changing, it is not difficult to find many examples of extreme events.

Let us once and for all learn from this, that climate change is real, and we must act now in a concerted fashion, before nature wreaks further havoc on our pitiful attempts to control it.

You can donate to the Queensland flood appeal here.

Credit to Rod Chester for the picture.

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Author: Graham

Graham Readfearn is a Brisbane-based journalist. Go to the About page in the top navigation for more information.

15 thoughts on “Climate change and the Queensland floods”

  1. Probably best not to get drawn into debates about is it or isn’t it? (although if you ever have to clean up in the wake of another thousand year event, the answer should be clear!)
    Rather, plan for the worst (in traditional conservative fashion)

  2. Arf – the point is, since the floods have been at least in part caused by human emissions, this means we have to urgently cut our emissions.

    It’s not enough to just prepare for the worst – we don’t want more people to die just because our politicians were too weak to stand up to the fossil fuel lobby!

  3. I agree that AGW is a likely contributor to severity of event. I grok the modelling, but my point is that one disaster does not provide definitive statistical proof of climate change (that would be another 1000 year event in the next ten years or so). Meanwhile, the debate has become polarised and nobody’s going to be swayed one way or the other (except after 1000 years’ clement weather, perhaps? … joke! 😉
    So, get on with whatever activity you consider to be most productive. By ‘preparing for the worst’ I would include preparing for our politicians being too weak to stand up to the fossil fuel lobby!

  4. Great update. At the end of the day it shouldn’t be political if the burning of coal is known to cause global warming and long predicted to bring us more regular, more intense climate events according to scientists, La Nina or no La Nina I would imagine!

  5. After 1000 of years of warming since the last major Ice Age and 250 years of warming since the coldest period of the Little Ice Age it won’t be surprising if there is another small amount of warming over the next 50 years regardless of the net effect of fossil fuel burning after allowing for the effects of water vapour and clouds.

    But let’s stop the idiotic prattling about it making sense for Australia to stop burning or exporting carbon based fuels except to a fraction of one per cent of Australians who are natural ascetics and hair shirt wearers. There is nothing Australia can do or say to affect what China, India and the US do to our climate (if anything).

    It seems like common sense to suppose that more energy (because more heat) in our atmosphere is likely to intensify major weather events like cyclones but so what? Let’s plan to make the best of something we can’t stop or control.

  6. Umm George, the last major ice age was over by 10 000 years ago, not 1000. Also the temperature trend since around 6-8 000 years ago had been one of slow cooling.
    Second why would you suppose the world should keep warming out of the “little ice age” if you to take out the effect of human GHG emissions? The planet doesn’t have a desired temperature set point, it simply responds to the sum of the heating and cooling influences. To put it simply, human GHG emissions have made heating influences dominant so we warm.

    I could go on, but the thought that most strikes me is, shouldn’t you at least learn some basics in the topic you’re opining on before accusing others of “idiotic prattling”?

  7. I know that Mike C has learned the basics of picking up a typo but there is no evidence otherwise to justify his sense of superiority. To the contrary, as he has failed to notice that my argument relating to the “idiotic prattling” is an argument completely independent of the likelihood or otherwise of CO2 emissions being the, or a major cause, of continued warming in the 21 century.

    By the way has anyone got adequately detailed accurate scientific explanations of why variable warming has occurred at verious times in the last 10,000 years – some of it with horrendous conseqences?

    Try an elementary clear thinking course first.

  8. Well George you certainly excel at bluster. But might I politely suggest that you carefully check your numbers in the future, grammatical errors are fine but getting your numbers wrong is a bit embarrassing eh?

    As for your question, well it’s a bit vague, do you mean warming on a global scale or local scale?
    Global temperatures since the beginning of the holocene have been pretty stable and showed a slow decline. NOAA point out that “In summary, the mid-Holocene, roughly 6,000 years ago, was generally warmer than today, but only in summer and only in the northern hemisphere. More over, we clearly know the cause of this natural warming, and know without doubt that this proven “astronomical” climate forcing mechanism cannot be responsible for the warming over the last 100 years.”
    I also checked IPCC AR4 chapter 6, as well as more recent reconstructions by Mann 09 and Kaufman 09 and don’t see good evidence for periods of significant warming on a global scale. Perhaps you could specify which periods of warming you mean and what horrendous consequences you are referring too?

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