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Bushfires and extreme heat in south-east Australia

Filed under: — group @ 16 February 2009 - (Deutsch) (Español) (Italian)

Guest commentary by David Karoly, Professor of Meteorology at the University of Melbourne in Australia

On Saturday 7 February 2009, Australia experienced its worst natural disaster in more than 100 years, when catastrophic bushfires killed more than 200 people and destroyed more than 1800 homes in Victoria, Australia. These fires occurred on a day of unprecedented high temperatures in south-east Australia, part of a heat wave that started 10 days earlier, and a record dry spell.

This has been written from Melbourne, Australia, exactly one week after the fires, just enough time to pause and reflect on this tragedy and the extraordinary weather that led to it. First, I want to express my sincere sympathy to all who have lost family members or friends and all who have suffered through this disaster.

There has been very high global media coverage of this natural disaster and, of course, speculation on the possible role of climate change in these fires. So, did climate change cause these fires? The simple answer is “No!” Climate change did not start the fires. Unfortunately, it appears that one or more of the fires may have been lit by arsonists, others may have started by accident and some may have been started by fallen power lines, lightning or other natural causes.

Maybe there is a different way to phrase that question: In what way, if any, is climate change likely to have affected these bush fires?

To answer that question, we need to look at the history of fires and fire weather over the last hundred years or so. Bushfires are a regular occurrence in south-east Australia, with previous disastrous fires on Ash Wednesday, 16 February 1983, and Black Friday, 13 January 1939, both of which led to significant loss of life and property. Fortunately, a recent report “Bushfire Weather in Southeast Australia: Recent Trends and Projected Climate Change Impacts”(ref. 1) in 2007 provides a comprehensive assessment on this topic. In addition, a Special Climate Statement(ref 2) from the Australian Bureau of Meteorology describes the extraordinary heat wave and drought conditions at the time of the fires.

Following the Black Friday fires, the MacArthur Forest Fire Danger Index (FFDI) was developed in the 1960s as an empirical indicator of weather conditions associated with high and extreme fire danger and the difficulty of fire suppression. The FFDI is the product of terms related to exponentials of maximum temperature, relative humidity, wind speed, and dryness of fuel (measured using a drought factor). Each of these terms is related to environmental factors affecting the severity of bushfire conditions. The formula for FFDI is given in the report on Bushfire Weather in Southeast Australia. The FFDI scale is used for the rating of fire danger and the declaration of total fire ban days in Victoria.

Fire Danger Rating           FFDI range
High                          12 to 25
Very High                     25 to 50
Extreme                         >50

The FFDI scale was developed so that the disastrous Black Friday fires in 1939 had an FFDI of 100.

To understand the environmental conditions associated with the catastrophic bushfires on 7 February 2009, we need to consider each of the factors and the possible role of climate change in them.

Maximum temperature: This is the easiest factor to consider. Melbourne and much of Victoria had record high maximum temperatures on 7 February (2). Melbourne set a new record maximum of 46.4°C, 0.8°C hotter than the previous all-time record on Black Friday 1939 and 3°C higher than the previous February record set on 8 February 1983 (the day of a dramatic dust storm in Melbourne), based on more than 100 years of observations. But maybe the urban heat island in Melbourne has influenced these new records. That may be true for Melbourne, but many other stations in Victoria set new all-time record maximum temperatures on 7 February, including the high-quality rural site of Laverton, near Melbourne, with a new record maximum temperature of 47.5°C, 2.5°C higher than its previous record in 1983. The extreme heat wave on 7 February came after another record-setting heat wave 10 days earlier, with Melbourne experiencing three days in a row with maximum temperatures higher than 43°C during 28-30 January, unprecedented in 154 years of Melbourne observations. A remarkable image of the surface temperature anomalies associated with this heat wave is available from the NASA Earth Observatory.

Increases of mean temperature and mean maximum temperature in Australia have been attributed to anthropogenic climate change, as reported in the IPCC Fourth Assessment, with a best estimate of the anthropogenic contribution to mean maximum temperature increases of about 0.6°C from 1950 to 1999 (Karoly and Braganza, 2005). A recent analysis of observed and modelled extremes in Australia finds a trend to warming of temperature extremes and a significant increase in the duration of heat waves from 1957 to 1999 (Alexander and Arblaster, 2009). Hence, anthropogenic climate change is likely an important contributing factor in the unprecedented maximum temperatures on 7 February 2009.

Relative humidity: Record low values of relative humidity were set in Melbourne and other sites in Victoria on 7 February, with values as low as 5% in the late afternoon. While very long-term high quality records of humidity are not available for Australia, the very low humidity is likely associated with the unprecedented low rainfall since the start of the year in Melbourne and the protracted heat wave. No specific studies have attributed reduced relative humidity in Australia to anthropogenic climate change, but it is consistent with increased temperatures and reduced rainfall, expected due to climate change in southern Australia.

Wind speed: Extreme fire danger events in south-east Australia are associated with very strong northerly winds bringing hot dry air from central Australia. The weather pattern and northerly winds on 7 February were similar to those on Ash Wednesday and Black Friday, and the very high winds do not appear to be exceptional nor related to climate change.

Drought factor: As mentioned above, Melbourne and much of Victoria had received record low rainfall for the start of the year. Melbourne had 35 days with no measurable rain up to 7 February, the second longest period ever with no rain, and the period up to 8 February, with a total of only 2.2 mm was the driest start to the year for Melbourne in more than 150 years (2). This was preceded by 12 years of very much below average rainfall over much of south-east Australia, with record low 12-year rainfall over southern Victoria (2). This contributed to extremely low fuel moisture (3-5%) on 7 February 2009. While south-east Australia is expected to have reduced rainfall and more droughts due to anthropogenic climate change, it is difficult to quantify the relative contributions of natural variability and climate change to the low rainfall at the start of 2009.

Although formal attribution studies quantifying the influence of climate change on the increased likelihood of extreme fire danger in south-east Australia have not yet been undertaken, it is very likely that there has been such an influence. Long-term increases in maximum temperature have been attributed to anthropogenic climate change. In addition, reduced rainfall and low relative humidity are expected in
southern Australia due to anthropogenic climate change. The FFDI for a number of sites in Victoria on 7 February reached unprecedented levels, ranging from 120 to 190, much higher than the fire weather conditions on Black Friday or Ash Wednesday, and well above the “catastrophic” fire danger rating (1).

Of course, the impacts of anthropogenic climate change on bushfires in southeast Australia or elsewhere in the world are not new or unexpected. In 2007, the IPCC Fourth Assessment Report WGII chapter “Australia and New Zealand” concluded

An increase in fire danger in Australia is likely to be associated with a reduced interval between fires, increased fire intensity, a decrease in fire extinguishments and faster fire spread. In south-east Australia, the frequency of very high and extreme fire danger days is likely to rise 4-25% by 2020 and 15-70% by 2050.

Similarly, observed and expected increases in forest fire activity have been linked to climate change in the western US, in Canada and in Spain (Westerling et al, 2006; Gillett et al, 2004; Pausas, 2004). While it is difficult to separate the influences of climate variability, climate change, and changes in fire management strategies on the observed increases in fire activity, it is clear that climate change is increasing the likelihood of environmental conditions associated with extreme fire danger in south-east Australia and a number of other parts of the world.

References and further reading:

(1) Bushfire Weather in Southeast Australia: Recent Trends and Projected Climate Change Impacts, C. Lucas et al, Consultancy Report prepared for the Climate Institute of Australia by the Bushfire CRC and CSIRO, 2007.

(2) Special Climate Statement from the Australian Bureau of Meteorology “The exceptional January-February 2009 heatwave in south-eastern Australia”

Karoly, D. J., and K. Braganza, 2005: Attribution of recent temperature changes in the Australian region. J. Climate, 18, 457-464.

Alexander, L.V., and J. M. Arblaster, 2009: Assessing trends in observed and modelled climate extremes over Australia in relation to future projections. Int. J Climatol., available online.

Hennessy, K., et al., 2007: Australia and New Zealand. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, M.L. Parry, et al., Eds., Cambridge University Press, Cambridge, UK, 507-540.

Westerling, A. L., et al., 2006: Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity. Science, 313, 940.

Gillett, N. P., et al., 2004: Detecting the effect of climate change on Canadian forest fires. Geophys. Res. Lett., 31, L18211, doi:10.1029/2004GL020876.

Pausas, J. G., 2004: Changes In Fire And Climate In The Eastern Iberian Peninsula (Mediterranean Basin). Climatic Change, 63, 337–350.

399 Responses to “Bushfires and extreme heat in south-east Australia”

  1. 51
    Lawrence Coleman says:

    I live in SE Queensland with is further north than Vic and SA so should be hotter but lickily our late summers are very humid and is that moisture that moderates our temperature. What has happened in Australia this summer is straight out of the climate change text-books. We are all aware of the extreme heat and dryness in the south giving rise to the bushfires but what you may not be aware of is that many parts of australia are experiencing 1/100 year droughts, that north queensland has been deluged for the past month or more by continous rain resulting in 2/3 of queensland being flood delared and $250mil worth of damage and counting. We have all the extremes running concurrently…drought,fires,record temps,major flooding and hurricane force winds. Australia’s temps have been getting progressively hotter and hotter over the last 40 years, but what I have noticed more and anything is that the climate is becomming increasing unstable..the regular El-nino/La nina cycles of the past that farmers planned sowing their crops by is virtually it’s a lucky dip what they get..usually a depressing continuation of this 10 year drought. Now the eastern seabaord of australia and california usually gets the same weather..weird.

  2. 52
    Sekerob says:

    Lawrence #51, few weeks ago read the Indian IOD cycle was identified as a major rain source, for NA, contrary to just ENSO regulated.

  3. 53
    truth says:

    David Karoly:
    I’m wondering why you fail to mention the announcements in recent days in Australia, that researchers from the CSIRO, UNSW Climate Change Centre and the University of Tasmania conclude from their research, that the extended droughts of South-Eastern Australia, and previous ‘iconic droughts’ in that area, [ eg the World War 2 drought of 1937-1945, and the Federation drought of 1895-1902 ]are caused , not by El Nino [ not primarily anyway], nor by AGW, but by the ‘variable and irregular cycles’ of the Indian Ocean Dipole.
    Does your neglect to mention this mean that you dispute their findings?
    As we in Australia know, droughts and bushfires have always been a constant in the Australian climate picture—since long before industrialisation and anthropogenic CO2 emissions.
    This was a really terrible fire, but it’s not Australia’s worst in intensity—–that was in 1851 according to historians, but back then of course the bush was largely uninhabited.
    As with hurricane Katrina in the US , the loss of lives now is huge, because so many people have increasingly chosen to live in the danger areas.
    It’s not only Victoria, South Australia and Canberra that have population areas interfacing with the bush.
    Many Sydney suburbs have streets adjoining National Parks bushland, and residents are required by local governments to leave in their backyards, the massive eucalypts that they know are what fuels the fire and would spread it ‘like wildfire’ through the suburbs if it were not for our wonderful people of the voluntary fire services.
    Some control burning is done, and fuel reduction carried out, but it always falls short of what’s necessary , due to the power of the environmental lobby—in Victoria, letters to authorities from residents begging for the mitigation are on record, and it’s the environmental red tape and over-legislation that causes the required measures to be postponed or canned.
    Incidentally, is it your contention that rural weather stations in Australia, where surrounding conditions and land use have remained unchanged—-show a strong warming trend?
    To what do you attribute the strong warming of the 1930s, when atmospheric CO2 levels were much lower than now?

    [edit – if you want serious responses, dial down the rhetorical flourishes]

  4. 54
    Richard Steckis says:

    #29 Lawrence Coleman:

    “By far the longest continuous heatwave in our recorded history.”

    I assume you mean the recorded history of Victoria and South Australia.

    The longest continuous heatwave in Australia’s and in fact the recorded history of the World was the heatwave in Marble Bar Western Australia.

    Duration: 183 days
    Dates: October 1923 to April 1924

  5. 55
    Ray Ladbury says:

    Harold Pierce Jr., As usual, you don’t have a clue. Trees are not the major danger when it comes to fire. Dry litter and undergrowth are where the fires start.
    As to attribution of the fires to climate change, of course one cannot attribute any one event to a “trend” like climate, just as one cannot attribute cancer in any one smoker to cigarettes. When you see unprecedented fires burning in Oz AND in SoCal, etc. AND when the IPCC predicts just these trends in advance the evidence becomes a lot stronger.

  6. 56
    Greg says:

    “Protracted drought”, “rainfall decline over Southern Australia”? Where’s that then?

    Popular delusions and the madness of crowds…

    [Response: In those diagnostics, the relevant one is SouthEastern Australia (which includes the region in question here). For instance here. – gavin]

  7. 57
    wmanny says:

    For a brief historical perspective of Australian bushfires:

  8. 58
    JCH says:

    the BraveNewClimate article helps explain the rationale for an AGW link here in addition to the obvious most important likely “cause” of arson. – 17 February 2009 at 4:47 AM

    I would think the most trivial item in the list of causes for this fire would be the alleged source of ignition. Fires are commonly started by arsonists, and by accidental ignitions, and by natural ignitions.

    Regardless of the source of ignition, usually fires don’t flare into uncontrollable infernos over a wide area that kill 200 people.

  9. 59
    Mark says:

    Further to Kevin’s post #50, Scotland USED to have a fairly abundant soil. Then humans cleared the land for farming and the soil wasn’t thick enough to stand without the trees. And so the modern view of Scotland is miles and miles of scrub grass and heather with a lot of bare rock. But that happened so long ago people now think that that is the unspoilt natural beauty of Scotland.

    But it used to be a lot of trees. Trees that protected the soil from the weather, held it against the elements and time and enriched it with their products.

    Now it produces shortbread tins.

  10. 60
    pete best says:

    Re #59, the whole of the UK was covered in the caledonian forest. Hardly any of it left now across the entire UK. Shame but there you are.

  11. 61
    Alan Millar says:

    Temperatures in the SH are currently running cooler than in 1988 the start of the alarmism. (Trends don’t contribute to fires actual heat does!). Australia as a whole was not exceedingly hot in January.

    If fires start more frequently then, perversely, there will be less damage over all as it is the unburnt accumulation of bracken, shrub etc that really transforms local fires to huge conflagrations.

    [edit – not an appropriate phrasing]


  12. 62

    Maybe Al Gore & Kevin Rudd need to talk.

  13. 63
    duBois says:

    Regardless of the source of ignition, usually fires don’t flare into uncontrollable infernos over a wide area that kill 200 people.

    Exactly. Mrs. O’Leary’s cow may have started a fire, but Chicago burned because it had lots of wood buildings jam-packed together. The current fire’s occasion may have been arson, but that’s simply the difference between necessary and sufficient causes. S.E. Australia had become a tinder box due to drought. Something was going to cause a fire.

  14. 64
    Ike Solem says:

    Re#53, Yes, that is the fossil fuel lobby response to global warming – blame it on “natural cycles” – for example, try the San Diego Union Tribune on drought in California: La Nina blamed for more drought:

    Yes, meteorologists are still talking about continued drought in their long-range predictions. La Niña is the culprit.

    Very definitive statement, isn’t it? This is typical of the coverage by the press – and even mild-mannered climate scientists are calling for change on that:

    “Business managers of media organizations, you are screwing up your responsibility by firing science and environment reporters who are frankly the only ones competent to do this,” said climate researcher and policy analyst Stephen Schneider, in assessing the current state of media coverage of global warming and related issues.”

    Odd, though – I don’t see any reporters picking up on that press release, do you? “Yes, we have distorted the issue for the benefit of the fossil fuel lobby” – no, I don’t expect that headline.

    Let’s consider the real science instead: we know that basin-scale ocean-atmosphere oscillations influence precipitation and temperature pattens on a global scale. I prefer the term wobble, as in the Southern Wobble, the Pacific Decadal Wobble, etc., as that better fits the actual behavior. However, keep a few things in mind:

    1) These oscillations are nothing new – they were going on at the beginning of the 20th century, when global temperatures were cooler.

    2) If a mass on a spring is oscillating, and you heat up the spring, does the oscillating behavior change? Yes, it does – and we can expect that similar effects will occur with ENSO, etc.

    3) We know that global warming is shifting atmospheric circulation patterns on a global basis, with associated changes in water vapor distribution. Ocean circulation pattern changes may be happening, but are hard to detect.

    Put another way, could any of these natural cycles be responsible for the warming oceans, the melting poles, and the expanding subtropical dry zones? Perhaps in one specific location, the argument could be made – but this isn’t just Australia. It’s California and the U.S. Southwest, Argentina’s Pampas regions, China and Africa – it’s a global phenomenon, and what it appears to correlate with is the global warming induced expansion of the subtropical dry zones, as predicted by models and observed in the real world.

  15. 65
    Abi says:

    I understand the difference between weather and climate, but I’m unsure about when weather becomes climate.

    At what point does weather (pattern) become climate? Do we have to wait for the end of the climate trend (about 30 yrs) to proclaim that the climate has changed, or can we do so during the trend, and if so, at what point? Also, do we need to wait for experts to tell us what is happening, just like in this thread or can we assume it, based on our own local experiences?

    Our last couple of summers here in the UK have been a wash-out, which is in line with climate change predictions for our part of the world, yet we’re not really allowed to say it’s climate change. How many years of such consecutive summers do we need to say our climate has changed? Also, can we say “our climate is changing”, after a few years of noticeable and predicted changes?

    It would be nice if we could have proper guidance on the issue of transition, particularly as it is bound to become more prominent in the near future with changing weather around the world. Also, without it, deniers will continue to exploit any uncertainty.

    Finally, is there a list/catalogue of climate change events around the world, e.g. the droughts, fires etc?

    Many thanks for your help.

  16. 66
    Rod B says:

    I’m not sure (yet) if I agree with Karoly’s conclusions or not, but I am very impressed with what clearly is a learned, objective, and scientific treatise, seemingly free of prejudices and orthodoxies.

  17. 67

    So, who caused the fires and killed the people in Australia? The arsonists and us.

    Of course, we could always “blame the victims,” which is what they did to the Love Canal mothers for failing to prevent their children from playing on the grass.

    But for me the “musical chairs blame game” stops here. I’ll continue to reduce my greenhouse gas emissions, while the scientists trudge on in their becoming evermore confident of my role in the harms, while the policy-makers dilly-dally, while denialists deny; and I’ll let the Australian criminal justice system take care of the arsonists, and let people in fire-prone areas figure out safer places to build or rent homes.

  18. 68

    Alan, I’d be curious as to your source, as your statement doesn’t accord well with the SR ’05 data for January ’09, just posted by the NCDC:

    Southern Hemisphere anomalies & rankings

    Land: +0.53°C (+0.95°F)–10th warmest January in instrumental record.
    [Record year: 2006 (+0.78°C/1.40°F)]

    Ocean: +0.45°C (+0.81°F)–8th warmest.
    [Record year: 1998 (+0.55°C/0.99°F)]

    Land and Ocean: +0.46°C (+0.83°F)–7th warmest.
    [Record year: 1998 (+0.58°C/1.04°F)]

    Hopefully January meets your idea of “currently” well enough. :)

  19. 69
  20. 70
    tamino says:

    Re: #64 (Ike Solem)

    I prefer the term wobble, as in the Southern Wobble, the Pacific Decadal Wobble, etc., as that better fits the actual behavior.

    You are *so* right! I’m often frustrated by naming them “oscillations,” which implies some periodicity to the behavior when there’s really no reliable evidence of periodicity in these phenomena. Some of them show characteristic time scales, but not periods.

    By the way, I find your comments are consistently well thought out and on point.

  21. 71
    Greg says:

    Yes, that link will do nicely Gavin. It shows that current rainfall isn’t any different to the entire 1900-1950 period. So I ask again, “rainfall decline over Southern Australia”??

  22. 72
    tamino says:

    Re: #71 (Greg)

    It looks like you’d rather take a simpleton’s approach — any graph that allows you to maintain a delusion — than do the work required to understand what’s really involved.

  23. 73
    Bill DeMott says:

    Yes, that link will do nicely Gavin. It shows that current rainfall isn’t any different to the entire 1900-1950 period. So I ask again, “rainfall decline over Southern Australia”??

    71. Comment by Greg — 17 February 2009 @ 3:06 PM


    My reading of the graph indicates that wet season rainfall has been below the long term average for the last 11 or 12 years. Moreover, the rain deficit has gotten worse in the last several years. There was another long term drought in the 1930’s as well. Evidently people living in the area look at vegetation and realize that there has been a severe drought for over 10 years.

  24. 74
    wmanny says:


    Not the list you were looking for but certainly a topical one.

    The earliest recorded Victorian bushfire was in 1851, climaxing on 6 February or ‘Black Thursday’. By 11am that day the temperature had soared to 47 degrees celsius in the shade, conditions which saw the bush burn from Barwon Heads to Mount Gambier, 10 deaths.

    ‘Red Tuesday’ – 20 January, 1898: towns were razed and several people killed as fires swept across the Otway Ranges and south and west Gippsland.

    ‘Black Sunday’ – 13 February, 1926: fires devastated the central highlands of Victoria claiming 31 lives.

    ‘Black Friday’ – 13 January, 1939: with rivers at their lowest levels for 80 years and humidity at eight per cent, 71 lives were lost to fires and the town of Noojee destroyed.

    ‘Ash Wednesday’ – 16 February, 1983: fires burned from the Dandenongs to the Otway Ranges and on to the Adelaide Hills. 73 dead

    In January 1985, at least 12 bushfires and 240 minor blazes swept across Victoria. Six people were killed and 66 injured in blazes at Maryborough, Avoca and Little River. The fire destroyed 182 homes, 400 farms and 46,000 livestock.

    In January 1997 fires raged across the Dandenong Ranges, Creswick, Heathcote, Teddywaddy and Goughs Bay. 2 died.

  25. 75

    When can we label weather as caused by global warming? Or maybe just “consistent with global warming”

    No weather event can ever be labeled as caused by global warming, at best only linked. Can it? Can anyone imagine if there any clear case possible?

    Even a new and unseen weather event – like a Category 6 hurricane or a super tornado or a ball-lightning storm, nothing can ever said to be caused by global warming. But instead a rare confluence of blah, blah…

    But can we say the converse? That without global warming, in a climate of 20, or 50 years ago that these events would not happen?

    In the face of fires, floods, drought, I am frustrated that there is not stronger language, perhaps simplified, that locks in the connection.

  26. 76
    Jerry Toman says:

    When I’ve posted at this site in the past, nobody has paid much attention to what I have had to say, perhaps because I’m not a “climate scientist”. However, it didn’t stop me then and it won’t stop me now from posting my theory.

    There has been some discussion in this thread about the Urban Heat Island (UHI) and its possible effect on wildfires. I have pointed out (don’t remember where) that such an effect could have worsened (from FI#1 to FI#2) the tornado that crossed downtown Atlanta, about a year ago.

    While temperatures in inner cities are frequently measured to be up to 5 C greater than the surroundings, someone here (#35) pointed out that the Melbourne fire occurred even when the central city temperature was lower than the suburbs.

    You also have a fire index (FFDI), but it appears to be only a calculated number, for which nobody has a good “feel”. In the north, we also have the calculated “wind chill” equivalent temperature, but even still people don’t pay as much attention to this as they do the actual temperature.

    I hypothesize that the potential for devastating wild fire is a combination not only of the dryness, number of days of high temperature without rain, etc., but also of atmospheric conditions, that have to do with the depth of the inversion layer.

    As is the case with thunderstorms in humid regions, these are may not triggered until the layer of free convection approaches the surface (see CAPE_Class). This tends to happen in the late afternoon.

    In a wildfire situation in a dry climate there is not enough humidity to trigger a thunderstorm, but a similar situation could quickly and greatly worsen any fire that might break out.

    Instead of just using a thermometer to measure current temperature and your FFDI, I propose that an inexpensive “wildfire potentiometer” also be constructed to supply additional information to the public.

    This would look like an “empty water tank” perhaps 20 x 20 meters in diameter. The walls on the bottom half would be opened and replaced by closely spaced airfoils (~1 wide, at a fequency of about one or two per meter of circumference), that would allow air to pass inward, and deflect the air tangentially at a uniform angle (say 45 deg. for a start). You could also put a “cone” in the center to help convert radial flow to vertical flow efficiently.

    It would be instrumented with anemometers or Pitot tubes that measure the converging wind flow velocity, as well as temperature, relative humidity and plume height rise (maybe with Doppler radar, after seeding with dust).

    It could be placed on a mild rise, mesa, or even a building (best in a city). You could also put them in the forests or other wooded areas.

    By showing a visual of this on the Telly (or whatever you call it in Australia), as well as broadcasting the FFDI, people could get a better sense of how dangerous the situation might be.

    You might need to burn something inside to get it going, initially (careful with those embers).

    Just a thought. (Oh, and you might also be interested in visiting

  27. 77
    truth says:

    Ike Solem : Re [64]:
    Are you suggesting that the CSIRO researchers and those from the two Australian universities who attribute the SE Australia droughts to the Indian Ocean Dipole effect , are fossil fuel lobbyists?
    Hardly—-and I don’t think David Karoly would suggest for a minute that they are.
    Those scientists made the point that ‘iconic Australian droughts’ from the past [ and some of the worst occurred long before heavy industrialisation and high CO2 emissions from burning of fossil fuels ], were caused [ according to their research], by the Indian Ocean Dipole.

  28. 78
    Hank Roberts says:

    Yeah, look it up, it’s even in the newspapers:

    “The current Indian Ocean warming pattern is unprecedented and probably related to climate change, researchers say.

    The report found that a phenomenon known as the Indian Ocean dipole plays a dominant role in determining temperature and rainfall in south-east Australia….”

  29. 79
    Pat N says:

    Earlier starts to the growing season increase the fire threat for later in summer. September 2008 was the warmest of record in the SH according to NASA.

    Trends show earlier spring thaws in the Upper Midwest.

  30. 80
    Hank Roberts says:

    Oh, Ike — re #53 and #78

    To belabor the point — the stuff from the userid “truth” was just spin, a misleading excerpt from the stories reporting climate change altering the Indian Ocean dipole — leaving out the climate change part and hyping it as disproving climate change.

    Could be just copypasting stuff from CO2Sci, WCReport, WTFU, or the Swindle thingers. Not even worth checking unless someone’s desperate for cites.

    Then trying to dope-slap you with the red herring “fossil fuel lobbyist” stuff. I mean, don’t even bother with this chit.

    There’s often a germ of fact behind the distorting mirror being promoted. Look around for that, don’t reply to the bogosity as though it were information.

  31. 81
    Hank Roberts says:

    p.p.s., for the definitionmongers, usage thus:

    Chits are a type of wargame counter that are generally not directly representational but used for the following purposes: * Tracking, being placed …

  32. 82

    Before you get too excited about WUWT posts (#45 Harold Pierce Jr), do some fact checking.

    The Mitchell Shire Council’s Minutes of 12 September 2005 clearly show that the claim that the trees were cleared for fire safety was an after the fact defense, and permission was not sought to clear them as required by the law. Opportunities to remedy the matter at lower cost were ignored.

    The Sheahans are not the innocent victims of bumbling bureacracy that they try to make themselves appear to be.

  33. 83
    William says:

    #20 Hank Roberts, dhogaza #19 and Dave Benson #18
    Before everyone piles on Joe Hunkins #15, a reading of David Karoly’s first citation (C. Lucas et al, Consultancy Report prepared for the Climate Institute of Australia by the Bushfire CRC and CSIRO, 2006) does not claim to prove that climate change has exacerbated fire danger. Please find the following quotes taken directly from the study:

    Page 49 “Is ths apparent recent increase in fire weather due to climate change or is it simply the reflection of some natural (and unforseen) interdecadal change? Unfortunately, it is not possible to answer this question unequivocally at this time.

    Page 51 ” The available data indicate that the fire seasons we have been experiencing for the last few years have been longer and in many ways stronger than any observed dating back to the 1940’s. It is not that a given day has a higher FFDI value rather, there are more VHE days and fewer low to medium FFDI days. A reasonable hypothesis for this behavior is that we are currently experiencing an upswing in fire danger due to some natural forcing with an interdecadal time scale, and that this is being exacerbated by the subtle ongoing effects of climate change.”

    Page 53 “Examining longer-term observations at eight stations, back to the early 1940’s in many cases, reveals considerable inter-decadal variability. Periods of increasing and decreasing fire weather danger are apparent in the record. The peaks of these cycles occur roughly every 20 years and the time series might suggest that we are at or near a peak, although there is no physical evidnce on which to estimate when or to what extent a decrease might occur.”

    Page 52 “Given the influence of ENSO on the climate of Australia, and particularly the southeast, understanding any changes which may occur in it’s behavior is paramount for understanding fire danger. Unfortunately, the current generation of climate models do not simulate ENSO particularly well. As noted earlier, there is a low-confidence projection that ENSO will likely stay the same. Any future changes in ENSO will likely affect the results presented here.

    My point in pulling these quotes out of the report is to illustrate that the causality of a “.6C increase in temperature over 160 years = more fires in Australia” is not exactly the slam dunk that is being portrayed on this thread. I encourage all to take the time to read the literature to get a broader understanding of the topic.

  34. 84
    Peter Martin says:

    It is worth knowing the level of global warming in a particular region rather than just assuming that the generally quoted 0.6 degC figure for the second half of the 20th century is applicable everywhere.

    The warming on land, globally, has been much greater:

    And the warming in central Australia has been greater still:

    Parts of central Australia have warmed by 0.5 deg C per decade since the mid 70’s which would make these regions some 2 degrees warmer now than they were then.

    Fire hazardous conditions in Australia’s more highly forested coastal regions are generally brought about by movement of air masses from the central region, an extra two degrees of warmth adding significantly to the danger.

  35. 85
    William says:

    Why look only at the period 1970 forward in your second link? Looking at the period 1910 forward the chart indicates warming of.10-.15C per decade. That’s quite a bit different than .5C per decade.

    You may wish to take another look at your GISS link. The chart plots variations to zero anomaly. Remember that temperatures at the conclusion of the “mini ice-age” took a while to warm back up to more “normal” levels.

  36. 86
    William says:

    #84 Peter
    You may wish to take another look at the GISS chart you link. It plots temperature anomalies compared to zero. Coming out of the mini ice-age in 1850 it took about 70 years to reach the zero anomaly level. .6C refers to above zero anomaly.

    I’m not sure why you selected 1970 as your starting point in the Australia temperature link but if you use all the data provided the warming falls to .10-.15C per decade. That’s quite a bit less than .5C per decade.

  37. 87
    dhogaza says:

    Earlier starts to the growing season increase the fire threat for later in summer.

    There’s been some good work published here in the US regarding the fact that invasive, native cheatgrass has altered fire cycles in shrub-steppe and shortgrass prairies (first annual up, first to dry, first to burn which moves the fire season forward, leading to more frequent and hotter fires as the stuff burns hot).

    And there’s other good work showing that cheatgrass is among the invasives moving their range northward.

    And other good work showing that the growing season overall in shrub-steppe at least is trending earlier, giving cheatgrass more time to dry out and be lit by summer electrical storms.

    Just one example of how climate change is interacting with our other efforts to totally screw up native ecosystems in an unpleasant way …

    While the details are different than SE Australia, the basic way in which climate change and other human impacts on the fire ecology interact negatively perhaps are not.

  38. 88
    Hank Roberts says:

    William, 9:19pm

    > does not claim to prove
    Of course not. Science doesn’t do proof. Straw man? Or didn’t you know that? If not please ask for pointers to the explanation, it’s important for you to understand.

    > 1970
    look at the rate of CO2 increase before and after 1970. Remember the lag time (‘committed’ warming not instant).

    The 2006 paper predates, for example, these:

    If you look at nothing else but one picture, look at this one:

  39. 89
    Richard Steckis says:

    Richard Pauli:

    “But can we say the converse? That without global warming, in a climate of 20, or 50 years ago that these events would not happen?”

    No. We cannot say the converse.

    We know that there was a super El Nino of 30 years followed by a 30 year La Nina in the sixth century AD. That event brought 30 years of rain followed by 30 years of drought. It is regarded by some researchers as one of the causes of the collapse of the Moche civilization in Peru.

    These events would have most certainly affected Australia. Our climate is intimately linked to the El Nino/La Nina cycle, particularly in the east of the continent. Our experience is the oppostite of that in Peru. An El Nino brings rain in Peru and brings dry conditions in Australia and vice versa for La Nina.

    Therefore, the current drought in Australia is by no means unprecedented.

    [Response: Don’t confuse unprecedented with attributable. These are very different things. – gavin]

  40. 90
    William says:

    The “proof” language is from Karoly’s citation so I don’t get your comment about a straw man. I Looked to Wikipedia for a definition of the scientific method:

    “Despite the existence of well-tested theories, science cannot claim absolute knowledge of nature or the behavior of the subject or of the field of study due to epistemological problems that are unavoidable and preclude the discovery or establishment of absolute truth. Unlike a mathematical proof, a scientific theory is empirical, and is always open to falsification, if new evidence is presented.
    Even the most basic and fundamental theories may turn out to be imperfect if new observations are inconsistent with them. Critical to this process is making every relevant aspect of research publicly available, which allows ongoing review and repeating of experiments and observations by multiple researchers operating independently of one another. Only by fulfilling these expectations can it be determined how reliable the experimental results are for potential use by others.”

    I think it’s great that there are so many good climate science blogs where discussions like this can be conducted, where new observations can be tested and where we can all share publicly every relevant aspect of observations and experimental results so that they can be repeated and tested for reliability.
    Thanks for including me in this discussion.

  41. 91
    Ricki (Australia) says:

    Some more info:

    “Apparently from aerial imaging the temp was 3000c” — can anyone confirm this?

    When European settlement began, there was far less “fuel” on the forest floor due to the large number of small ground dwelling creatures such as Bilbies, Betongs, Bandicoots, etc. These creatures eat the plants and turn over the litter encouraging decay and enriching the soil. They have largly disappeared following the introduction of our dogs and cats, the clearing of habitat for cattle and the introductions of rabbits (who out-compete them) and foxes (who eat them).

  42. 92
    Stef in Canada says:

    Re: Jim Galasyn Says:
    > Thank you for this summary. I’ve been calling the Victoria fires the first climate-change disaster of the 21st century. Now I have a quick, thorough summary to link to.

    Jim, I tend to think of it as the second “What The Frak” disaster of the century. The 2003 European heat wave took around 35 000 souls:; and likely would not have happened without GCC. However, if you look around Wikipedia, you’ll find a great number of heat waves in recent years (the 2006 European and North American Heat Waves, the 2007 Asian Heat Wave, the 2007 European heat wave, etc.); most of these have incurred hundreds to thousands of excess deaths. Of course, some heat waves are natural in any event, but because mortality rates are locally exponential in temperature and duration, we’re likely to see a lot more poking into the extreme red over the rest of the century.

  43. 93
    Peter Martin says:


    Yes its just as valid to look at the changes in Central Australian temperatures from 1910 as 1970. I had to choose something from the menu!

    I must say that the data produced by the Australian Met office is excellent. If I have one small criticism it would be that the colour coding isn’t that easy to read. There’s sixteen shades but only fifteen numerical values.

    I have interpreted the values as best that I can, but if anyone disagrees…….

  44. 94
    James Killen says:

    #5 “I’ve been calling the Victoria fires the first climate-change disaster of the 21st century.”

    I think history we disagree with you and nominate Katrina instead.

    #11 “I would so love this to be published in the Sydney Morning Herald as a riposte to Miranda Devine’s recent piece blaming the fires on “greenies”.”

    Ms Devine’s column is hardly deserving of any riposte. Let’s be clear that her role on the left-of-centre SMH is as a rightist town fool on whom we can’t vent our spleen. Surely even she does not believe she is employed as a journalist (nor half of what she writes). Yes an article like this one ought be given greater prominence in our national media, but it is too sober to share a stage with Mirands.

  45. 95
    Greg says:

    Tamino, your post deals with drought (which you defined as involving both rainfall and evaporation) and a specific area (the Murray Darling basin, not Southern or even South-Eastern Australia). So I will ask for a third time, very simply, has there been any statistically significant change in long term rainfall in Southern or South-Eastern Australia? The answer is no. It has, at worst, returned to the long-term average seen between 1900-1950. This is a statement of fact. I’m not drawing any more conclusions from that, but you surely must concede that *for rainfall at least* there is no, as yet, apparent change in the climate of southern/south-eastern Australia.

    [Response: The Bureau of Meteorology in its Special Climate Statement 16 in October 2008 reports record 7-year low rainfall totals and record 12-year low rainfall totals for Victoria and Melbourne. These record low rainfall totals are also referred to in Reference 2 above. – David Karoly]

  46. 96
    DJA says:

    David Karoly has omitted one very important variable that of Fuel loading.I quote from FIRE CLIMATES OF AUSTRALIA: PAST, PRESENT AND FUTURE,Christopher Lucas
    Bureau of Meteorology Research Centre/Bushfire CRC, Melbourne, Victoria, Australia

    “The MaArthur Forest Fire Danger Index (FFDI) is an Australia-specific fire weather index,specifically geared toward dry sclerophyll (e.g.eucalyptus) forests with a fuel load of 12 t/ha.”

    There are reports of the fuel loading many times the 12t/ha (tonnes/hectare), one report was the fuel loading over 100 tonnes/hectare.

    We really need to understand what influence fuel loading has on extreme fires. This is more important than relating this fire to climate change.

  47. 97
    PHE says:

    Jerry Toman (77)
    I suggest you build one and see if it works.
    If it doesn’t, at least it will be an entertaining exercise, and can remain as a piece of modern art.

  48. 98
    Mark says:

    Greg, #95.

    Can we have access to the raw data and the source code/build scripts and sundry extras to validate your comment?

    Heck, just your data will do, but expect several people to demand that you provide all of them just like they ask of Eric et al.

  49. 99
    gjp says:

    There is a new paper accepted for publication in Geophysical Research Letters about south-west australia droghts:
    Ummenhofer et al. claims south-west australia droughts are a conseguence of indian ocean (the lack of negative IOD precede long term droughts), warmer temperature amplified PDSI response this time.
    Maximum temperature increase probably is also a conseguence of droughts due to lack of evaporative cooling.

  50. 100
    Dave says:

    Congrats to David for this post. I live in Victoria Australia, and I can tell you the weather here has been hell on this earth – record breaking unprecedented heatwaves and an awful unending drought.
    I have one message for the remaining idiot climate change deniers – come here and see it. Come here and see how a state which used to be called ‘The garden state’ is now turning into a foul baking desert racked by fire.

    Up until now the debate over climate change has been between the scientists, and the tinfoil hat morons and paid shills who deny the science. But now a new phase begins. The people actually living this hell – people like me, are going to aggressively get involved, because we are sick to the back teeth with what is happening to our climate and we want to go all out to stop climate change or stop it any further.

    So bring it on deniers – you have an open, standing invitation to come and visit Victoria and see it for yourselves.