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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. 151
    Ray Ladbury says:

    It is interesting to watch the gyrations denialists resort to in order divert attention from the central point of the post: Climate change predicts increased fire susceptibility precisely in those places where it has occurred–e.g. Southwest Oz, California, etc. True, no single fire can be attributed to climate change, just as no single cancer can be attributed to smoking. Trends, though, are a different matter, and climate science has excelled in predicting trends. The denialists…not so much.

  2. 152
    truth says:

    Florifulgurator: re [ 115]
    I replied to your question—without any of the sneering and venom that has been directed at me for having the temerity to ask a few questions and put a different view.
    But my reply was not posted.
    My post was just the facts of the economic crisis.

    [Response: This is not the place for a partisan argument over the current crisis. It’s definitely OT. – gavin]

  3. 153
    Hank Roberts says:

    > collecting up the leaf litter … rake the ground clear

    That was done by hand for a long time — many centuries — in Germany’s parklike forests, and I recall thought that the “waldsterben” forest dieoff might be related to that very long term, very meticulous removal of so much material. One factor among many.

  4. 154
    Geoff Wexler says:

    This is a most useful article followed by some interesting comments. Amongst other things it illustrates the fallacy in the argument which dismisses all past evidence based on single events as “weather” and therefore irrelevant in discussions about climate. This is well known to professionals but not to the lay public. Another example was the European heat wave in 2003 which was 5.4 standard deviations away from the expected value obtained from pre-global warming condtions.

    I very much like Tamino’s approach to teaching this subject which clearly separates observations from the underlying science and which therefore treats the former as pure data with trends, noise and standard deviations rather than ‘weather’ which is tied up with the science and which I suspect has more than one definition.

    The denialosphere are busy arguing that you cannot disregard a cold spell here while focussing on a heat wave there. The answer is contained in the standard deviations (as in Tamino), probability and also in this article and in Hank’s 3rd. link at #88 and the link to Grace released by SARDI therein.

    [Re: #40,43,48,65,75]

  5. 155
    dhogaza says:

    That was done by hand for a long time — many centuries — in Germany’s parklike forests, and I recall thought that the “waldsterben” forest dieoff might be related to that very long term, very meticulous removal of so much material. One factor among many.

    Not sure about forest dieoff, but it’s one aspect of German forestry not adopted by foresters here, and it’s a major reason why the biodiversity of German forests sucks so bad.

  6. 156
    Jim Eager says:

    Re Chris Colose @141: Indeed, the only thing A in AGW “theory” is the source of the rise in CO2. For AGW “theory” to be falsified everything we know about the non-anthropogenic greenhouse effect will have to be falsified as well. That means the “skeptics” will have to explain exactly why most of Earth’s surface is not locked in ice and permafrost, or at least why the natural greenhouse effect stops working well before atmospheric CO2 reaches 387 ppmv.

  7. 157
    John Mashey says:

    re: #147 Nick
    Don’t worry, I proposed sending *redwoods*, which are not Monterey pines. I wouldn’t send the latter, we don’t want the ones we have here. IN our town, they are a discouraged type of tree.

  8. 158
    Rod B says:

    Jim Eager (156) says

    For AGW “theory” to be falsified everything we know about the non-anthropogenic greenhouse effect will have to be falsified as well. That means the “skeptics” will have to explain exactly why most of Earth’s surface is not locked in ice and permafrost, or at least why the natural greenhouse effect stops working well before atmospheric CO2 reaches 387 ppmv.

    Most skeptics do not try to falsify everything behind AGW. (The fringe that do don’t count.) We are skeptical about certain aspects of the “theory” or on the degree of effect from some aspects. We have zero obligation to explain what you said. The “proponents” on the other hand need a bit more than a large standard deviation of the temperature in Podunk two years ago. (Some, but not all, do have…)

  9. 159
    Joe Hunkins says:

    Ray – I’ve no beef on underbrush’s important role here and after looking into it I may have overstated the role of the trees in these fires above – not clear on that yet.

    Ray when you state AGW appears to be a great fire prediction tool are you just talking about IPCC and other general statements or has this been tested?

    It seems folks here are suggesting that despite many other seemingly large factors (e.g. arson) AGW is the ‘straw that fired up the camels back’. I still see no good reason or data to support this sort of “AGW warming is what crossed the fire threshold” contention – that conclusion seems contrived to me though if a study supporting what Ray says exists it would suggest otherwise. Tamino’s ‘Australia’ post does not address this directly unless I’m missing his key point entirely – that is always possible of course.

    Barton Paul: And I think doing nothing about global warming will hurt the economy far more than any mitigation effort possibly could.

    Of course you can think whatever you like, but truth’s claim above is much more in line with most of the published research and expert opinion. There is a lot of economics work on this topic that suggests moderate mitigation is optimal rather than massive mitigation. Solomon at Yale, IMO, offers some of the best insight about this topic.

  10. 160
    Hank Roberts says:

    > redwoods
    Here ya go, good climate for them:

    Chuckle. You should see N. Ca. where I do restoration in my hobby hours.

    Want something worse than Monterey pine?

    We have knobcone pine.

    Fast growing, soft wood, only releases seeds during fires. No commercial use whatsoever, as I understand, except making kitchen matches. Diamond Match Company is, I think, the only market. Great for that — light, soft, burns well. Not much market any longer though.

    It replaces everything where we have forest fires, seeding like mad right after the flames pass, and when that next generation thick on the ground comes to burn, it burns hot enough to burn the topsoil off right down into the gravel layer.

    I take kids camping on my restoration site, point it out, and teach them the old skills of saw and hatchet and when they get tall enough will teach them to swing an axe. Amazing how few opportunities there are these days for kids to go chop down trees.

  11. 161
    Jim Eaton says:

    Hank, I’m not sure why you dislike a native species like the knobcone pine. After all, it often is found on serpentine sites on which few other tree species do well. It requires fire to regenerate, and if fires occur too frequently, chaparral will take over instead.

    No, I don’t have one in my yard (which is not serpentine), but I do have a dawn redwood which is doing quite well. :-)

  12. 162
    truth says:

    Re the response to Marc H [129]:
    To suggest that there are other impacts on the earth over the last 60-100 years that , along with possible natural cycles , should be considered as causes of whatever warming there is now—is not to be ‘stupid’—and is not to have the premise that it must be anything but CO2.
    It’s just to say that a great deal has happened to the earth during that time besides CO2 emissions—and maybe the warming has more to do with those impacts.
    There have been billions of human beings added to the population, with all the individual impacts they bring—their land use changes—farming animals, land-clearing etc.
    There has been an enormous amount of deforestation—– incredible building programmes, turning rural areas into built-up environments—-massive amounts of concrete.
    And lets be real—–of course these impacts are anthropogenic, but we all know that when the warming is labelled ‘anthropogenic’ by the AGW proponents, they’re talking about CO2.
    Marc H’s comments are very rational and reasonably stated.
    Why is it that these very considerable impacts on the earth in the time-frame we’re looking at, are just dismissed and ridiculed—the only acceptable response —the only one that avoids a put-down or vitriolic attack, being one that unquestioningly attributes warming to CO2?
    This seems especially puzzling, when we know, from reading about the various elements and influences that are involved in the climate picture— [and the IPCC and other climate science bodies and researchers regularly say this]—- that there is so much that is still unknown about many of the processes involved—in the oceans and the way they process CO2, cloud science, solar insolation etc.
    The demands of the CO2 response , brings with it, for individual countries, economic impacts that make it enormously more difficult to mitigate the other impacts—and will also necessarily restrict research into the whole climate picture—-and into renewables.

  13. 163

    pete best (#105)

    nice one Dave. Its about time joe (average) got mad and started demanding the start of the new era in energy provision. Australia has a track record of love of coal

    I’m running for Greens in the 2009 Queensland state election and I thought one of the really hard problems the state had to deal with was balancing the budget if coal royalties went away. I started digging for the figures, which turned out to be pretty hard to find, but here they are.

    Qld state budget summary, 2007-8 revenues: $32,276M

    Coal royalites: year ended June 2008 $1,034.8M.

    Tell me if I have my calculation of coal royalties = 3.2% of state revenues wrong. This number is so unbelievable with all the fuss made about how critical coal is to the state budget that it has to be a mistake. Maybe some of the climate science and physics PhDs here can help me. My computer science PhD is obviously not good enough to make sense of this :(

  14. 164
    James says:

    Re Redwoods to Australia: You might want to send Giant Sequoia rather than Coast Redwood, as it tolerates much drier conditions. Specimens do well in Northern Nevada, which I’m told is a similar climate to that part of Australia.

  15. 165

    David writes:

    The usual problem is the high cost of centralizing the biomass.

    What, it costs so much to centralize the biomass called “Food” and “Garbage” that no one can afford to eat or send their trash to the dump?

    Once again, gloom-and-doom stands in the way of what is so simple that Americans are both obese and filling landfills as fast as possible.

  16. 166
    Hank Roberts says:

    > knobcone

    Actually I’m very hopeful someone will come up with a use for the stuff. It’s just that in doing forest fire restoration it’s a nasty weedy fast-growing tree that can make the _second_ fire far worse than the first one. In a mature patchy forest, it only finds good opportunities on serpentine or after spot fires. But in contemporary Dep’t of Agriculture/ OHV / eroded forest land, it can take over many places because they lost their foot of topsoil since a century ago. It’s just as fire adapted as cheatgrass or medusahead. Nasty because of the fact that it follows _people_. Like rats or kudzu. Lovely creatures in their niches in an established ecosystem. Trouble when they accompany human devastation because they like those conditions.
    A six year old with a bowsaw can take down a 15-year-old knobcone that’s 15 or 20′ high, it’s soft wood, easy to cut.

    There’s a grant opportunity here:

    “… woody biomass utilization grant applications for 2009. This nationally competitive grant program seeks applicants that can demonstrate an increased use of woody biomass from forest restoration and hazardous fuels projects on National Forest System lands where little or no capacity to economically use this low value material exists. Visit the TMU 2009 Woody Biomass Grants web page
    for more information and the complete application package.”

    Think about it. You could “economically use” this stuff for biochar and get both fuel and carbon credits out of it, maybe.

    Anyone? Pass the word ….

    (No personal connection to this, except it’s a pestiferous tree for the little bit of restoration I’m doing and the forest is full of it for miles and miles, wherever there was a fire in the past 50 years.)

  17. 167

    Rod B writes:

    Most skeptics do not try to falsify everything behind AGW. (The fringe that do don’t count.) We are skeptical about certain aspects of the “theory” or on the degree of effect from some aspects. We have zero obligation to explain what you said. The “proponents” on the other hand need a bit more than a large standard deviation of the temperature in Podunk two years ago. (Some, but not all, do have…)

    The SCIENCE is rock solid. Anyone who disputes the SCIENCE doesn’t know what a greenhouse gas is or how they work.

    I think — just my opinion — that the only outstanding areas for genuine skepticism are

    1). How much of “climate” is that big ball of fire? I think this will be answered by SC24. However, even if that big ball of fire has an impact, the process is just put off by some number of years, not avoided completely.

    2). How realistic are CO2 level projections? This gets back to ‘fossil fuels are only going to get more expensive as time goes on” and the impact of that on the economy. Is ‘BAU’ possible without destroying the economy (not that it’s all that healthy at the moment)?

    Bottom line is that if CO2 ppm goes to some huge number, and SC20-something returns to normal, we’re basically screwed.

    (reCaptcha sez: “Krewe Ma-“. Yes, it is Mardi Gras time of year.)

  18. 168
    John Mashey says:

    re: #162 James
    I didn’t specify redwood type, but I did say Canberra, specifically because most of the times I visited, it was often cool and foggy, consistent with Oceanic climate, specifically Koppen Cfb.

    San Francisco has a similar temperature & total rainfall range (but no rain in summer, hence Csb). I think there are many parts of the CA coastal mountains whose climate isn’t so different from Canberra’s. Canberra’s rainfall is ~90% of Portola Valley, coast redwoods grow right here, although they definitely want the fog in the summer for moisture. They grow better slightly uphill from here. Of course, all this is confused by the microclimates around here, via which redwoods grow in one canyon, but not in the next.

    But yes, in many areas of Oz, if redwoods could grow there, Giant Sequoias might be better. Of course, given the sad history of importing *anything* to Australia, even redwoods might not be a good idea…

  19. 169
    dhogaza says:

    Specimens do well in Northern Nevada, which I’m told is a similar climate to that part of Australia.

    Regardless of whether or not introduction of another potentially invasive species makes sense, northern Nevada gets friggin’ cold in winter – minus 20C, 30C, 40C etc – where exactly in Australia do similar winter conditons occur?

  20. 170
    Hank Roberts says:

    Oops. Dang, that’s an “Eastern Forests” grant. Keep looking …

  21. 171
    James says:

    dhogaza Says (20 February 2009 at 12:34 AM):

    “…northern Nevada gets friggin’ cold in winter – minus 20C, 30C, 40C etc…”

    It does? Funny, I’ve lived here 30 years or so, and don’t think I’ve ever seen it below 0F (-17C), and that’s rare. A typical winter here might see nighttime lows in mid-20s (-10C).

    As to importation or not, much as I like growing more-or-less native plants, it seems that as the climate shifts, the choice will be increasingly between introducing new types of plants that can cope with the changed climate, or not having much of anything grow at all.

  22. 172
    Nathan says:

    Good luck in QLD, you’ll need it!
    You may also want to find out how much tax revenue was paid by the Coal companies and the workers… It’s more than the Royalties.

    Is there much prospect for hot rock geothermal over there (I’m in WA) I nkow the state Govt here will be charging a royalty for energy produced from hot dry rock geothermal, so it may be a way to balance out the loss of coal?

  23. 173
    Rod B says:

    Furry- (167) what I contend is that some — maybe even most — of the science is what you call ROCK SOLID; other aspects or parts are not. Your examples are a case in point, though I probably would not classify CO2 projections a part of the science per se. One part that I contend is loose (and have done so in RC a number of times) is the marginal increase in forcing from a marginal increase in CO2. Another example (though somewhat related) is the degree and process of band spreading in CO2’s radiation absorption as its concentration increases.

  24. 174
    Jim Eager says:

    Re Rod @158: “We have zero obligation to explain what you said.”

    Then there is zero obligation for anyone to take any of your objections seriously, Rod.

  25. 175
    J says:

    From mike’s inline response to William (#130 above):

    “AGW” therefore combines attributes which are indeed ‘theoretical’ in nature, and others which are merely phenomenological. As such, it is not a ‘theory’ in the standard sense of the term. For an analogy, there is a ‘theory of gravity’ but there is not a ‘theory-of-gravity-making-apples-fall’. -mike

    I like to use the analogy of plate tectonics. Plate tectonics is a fairly complicated theory about global-scale processes. The theory as a whole can’t be tested in the lab in the classical “experimental” sense, so evidence for it has to be deduced from observations and from computer models.

    Likewise, climate change due to radiative forcing from greenhouse gases is a fairly complicated theory about global-scale processes. While we can measure things like CO2 absorption spectra in the lab, the theory as a whole involves ocean-atmosphere exchanges, cloud feedbacks, etc., which can mostly only be observed in-situ or deduced from models.

    The phenomenon of the Himalayas being forced up by the collision of India and Asia is a real-world phenomenon that illustrates the theory of plate tectonics in action. Likewise, the phenomenon of modern global warming via anthropogenic CO2 (and CH4, and CFC) emissions is a real-world phenomenon that illustrates the broader theory of the relationship between atmospheric gases and climate. Other specific “instantiations” of this abstract theory can be seen by looking at Venus’s atmosphere, or at other points in the Earth’s history (the PETM, etc.)

    Unfortunately there isn’t a really good, snappy name (analogous to “plate tectonics”) for the overall theory of “radiative forcing of a planetary climate by atmospheric gases”, at least not any that I find satisfactory (the “Greenhouse Effect” isn’t great, because the analogy of a greenhouse doesn’t really describe what happens here).

  26. 176
    Brian Brademeyer says:

    The southern sea ice also seems to be in free-fall —

  27. 177
    David B. Benson says:

    FurryCatHerder (165) — Unfortunately it is indeed the case that biomass collection costs are high enough to prevent (so far) competing with coal on anything but the smallest scale. If the biomass is already centralized, nut shells for example, then the costs of transportation to a nearby coal-fired electric generator are small enough that some co-firing is being done. My example is near St. Louis.

    Another example is wastes from forestry operations. I know of two 100% wood fired electric generating stations in the U.S. The one about 200 km from here generates 57 MW, not much.

    A largely untapped potential is in municipal waste management where an anaerobic digester is a most excellant idea. I only know of two such in the U.S. which are generating useable energy, one electricity and the other biomethane.

    [reCAPTCHA agrees this is a good direction by entoning “decades thrust”.]

  28. 178
    dhogaza says:

    Googling I see that Elko’s average minimum in December is 13F. That’s -10C as an average minimum, so certainly colder (as well as warmer) nights aren’t going to be uncommon. The coldest temperature recorded in Elko is -41C.

    OK, guess I should’ve said “-10C, -20C, -30C even -40C” … rather than “-20C, …”

    Still friggin’ cold by my standards.

    Now, can you find me a place in Australia that has an average minimum temp of -10C for a winter month?

  29. 179
    Phil Zylstra says:

    Thanks a lot for that David. One factor that the FFDI does not consider adequately is the role of long-term heatwaves. Protracted high temperatures certainly raise the KBDI which in turn affects the Drought Index and has an influence on the overall FFDI, but I believe that the direct impact of a heat wave on live fuel moistures has a profound influence on fire behaviour, particularly in tall complex forests.

    Although I have no direct figures to examine for E. regnans, accumulated high temperatures certainly play a role in accelerated drying of Eucalypts in my own study area just as they have been found to do in a range of other species and sites internationally. A dry vegetation profile means reduced ignition delay times (time taken for a plant to catch fire), which in turn facilitate the spread of flame both upward into the crowns and horizontally in a faster rate of spread.

    Initial modelling suggests that if the heat wave was able to drop the moisture content of Eucalypts to the point of severe moisture stress, the rate of spread for the same FFDI may be up to 6 times faster following a heat wave. If we are expecting more such heatwaves with climate change then I expect more record-breaking rates of spread. There is also the possibility of a positive feedback in fire frequency & intensity for areas that produce dense regrowth.

  30. 180
    Ray Ladbury says:

    Rod B. says “One part that I contend is loose (and have done so in RC a number of times) is the marginal increase in forcing from a marginal increase in CO2. Another example (though somewhat related) is the degree and process of band spreading in CO2’s radiation absorption as its concentration increases.”

    Once you understand this portion of the science, come back to us and tell us if you still think it is uncertain. Rod, we KNOW that you don’t understand this yet. We’re the ones who have been trying to explain it to you. It is not eash physics, granted, but to equate YOUR understanding with that of folks who do this for a living doesn’t wash.

    Or, if you are convinced that you have some insight that a hundred years of physicists have missed, outline the basis for your doubts.

  31. 181
    Hank Roberts says:

    > southern sea ice
    NSIDC says they’re having trouble with the sensors and not to rely on the charts — see their main page for the info. I think they’ve removed the links to those imagery on their own page until they get that sorted out. Direct links right now go to unreliable pictures.

  32. 182
    Hank Roberts says:

    > redwoods, rainfall
    John, turns out redwoods, being social organisms, harvest water from fog quite well. It’s called “occult precipitation” apparently.
    There’s predictable argument over whether clearcutting, by halting that process, also interferes with reestablishment of redwoods. Likely applied worldwide. Forest service papers say there’s just as much groundwater after clearcutting, but I have my doubts they account for the groundwater not used by the trees that were logged.

    Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract B14A-03 INVITED
    TI: Occult precipitation and plants: its consequences for individuals and ecosystems
    AU: * Dawson, T E
    AF: U.C. Berkeley, Department of Integrative Biology

    AB: Fog, dew and cloud water inputs, aptly termed, –occult precipitation” … we now know that plants inhabiting a wide range of ecosystem types from the coastal California redwood forests and grasslands, to the Brazilian Cerrado (savanna), the Chilean community types are utilizing fog, dew and cloud water. Hydrogen and oxygen stable isotope analysis have revealed that both fog drip into the rooting zone and direct foliar-uptake of occult precipitation can occu

  33. 183
    James says:

    dhogaza Says (20 February 2009 at 5:41 PM)

    “Googling I see that Elko’s average minimum in December is 13F. That’s -10C as an average minimum…”

    OK, my fault for using a localism. To Nevadans, Elko is in Northeastern Nevada, while “Northern Nevada” means the area around Reno & Carson City. I don’t find anything in a quick search that gives lowest minimum, but here’s average lows in Reno: Much warmer than further east, and you might notice a considerable warming trend as well. Of course since the temps are taken at the airport, a good part of that might be heat island effect, but even well outside the urban area, the warming has been apparent just in the time I’ve lived here.

    “Still friggin’ cold by my standards.”

    Well, I guess standards differ :-) By mine, it’s almost subtropical. I’ll often ski in just a pair of sweats – my down jackets & wool sweaters haven’t been out of the closet in a long while.

    “Now, can you find me a place in Australia that has an average minimum temp of -10C for a winter month?” Doesn’t have numbers, but if the snow sticks around, it’d have to have an average minimum below 0C, no?

  34. 184
    Chris O'Neill says:


    there is so much that is still unknown about many of the processes involved—in the oceans and the way they process CO2, cloud science, solar insolation etc.

    which means we can assume that any changes we make to the system will be harmless because we don’t know for certain what their effects will be, i.e. what we don’t know can’t hurt us.

    The demands of the CO2 response , brings with it, for individual countries, economic impacts that make it enormously more difficult to mitigate the other impacts

    What an alarmist attitude.

  35. 185
    John Mashey says:

    re: #182 Hank
    Thanks for the new term, “occult precipitation” (actually, what we need here is some “magic precipitation”)

    Yes, that’s why we have a few redwoods on our property, and a block or two downhill, but not much further, as oaks become more frequent. During the summer, there are often days where morning fog comes down from the mountains and stops about a mile down the road towards Palo Alto. The microclimates may not be quite as sharp-edged as SanFrancisco, where there are “foggy blocks”, but you can still guess where there might be redwoods by watching the fog.

  36. 186
    Lab Lemming says:

    Re: redwoods in Canberra:
    The climate is too dry- there’s actually a stand out by the airport that was planted in the mid 20th century- scraggly, half dead, and not recovering well from a fire a few years ago. They are an occasional street tree, but many lost their crowns in the 2004 or 2005 summer.

    As for the northern hot dry winds, if the Diamantina is flooded more often, will that make them less dry, even if they are still hot?

    Last August, Thedbo top station had a mean low of -6, and Charlottes Pass had -7, with the lowest overnight temperature -15.

  37. 187
    Alan says:

    Thanks for this article.

    That Saturday I sat sweltering at home in Melbourne in the afternoon and kept an eye on the BOM site for the expected cold front. In the early afternoon I noticed the Bunyip and later the Kilmore fires appear on the radar (they look like storms but I knew otherwise).

    The wife came home about 4pm and we were due to drive to Wangarata (sic). I pointed out the fires, of which there was only scant reports on the news and said we had better hold off until the wind change because that would blow the fire to the NE rather than the SE. Between 5pm and 5:13 the temprature at nearby Morarabin airport dropped a full 15 deg celcius as the strong hot NW winds flipped to strong cool SW winds. We set off on our trip.

    I lived in Victoria for almost 50yrs and witnessed the ash wednesday and the ’69 fires up close and personal but I have never seen anything like the plume of smoke I saw as we drove out of Melbourne. I was later to learn that it was 15km high and was creating it’s own lightning and wind, more like a volcanic eruption that a bushfire. As we approached Kilmore around 8-9pm we were diverted off the Hume hwy and through the township, things got dark, quiet and very “spooky” but we got past the detour. An hour later we were at our destination glued to the T.V. reports that Kilmore was now isolated and surrounded by fire.

    Some other first hand accounts I read during that week reported engine blocks melting and a man who escaped but was badly burnt because his windsceen melted onto him as he sheltered under a blanket and the fire front roared over his car at 125km/hr. The immense speed and heat meant that very few people escaped with serious burns, as one doctor put it people either lived or were cremated on the spot.

    I cannot fathom the peculiar insanity of the arsonist(s) but that is because insanity has no explaination. However I do have a very ugly explaination for this seditious piece of anti-science hatred in the Sydney Morning Herald that lay the blame on the very people who fortold of such a disater in the 2007 report mentioned in your article and wrote “…it is not arsonists who should be hanging from lamp-posts but greenies.”.

    Note I have linked to the mediawatch report on the article because I refuse to click another SMH link until this woman is either sacked or brought before a court using the sedition laws that were drafted to curb radical Islamic hate mongers. I have written to both the SMH and Ms Devine stating my position and urge concerned readers of realclimate to take the time to do likewise.

  38. 188

    Re 185–right–there is so much unknown about many of the processes involved–in the national economies and the way they process mitigation costs, opportunity costs, offsetting benefits, etc.

    More selective skepticism. Ignorance relative to climate means “all’s well,” ignorance relative to adaptation/mitigation economics means “we don’t dare.”

    I so resent the efforts of those whose brief it is to protract or exaggerate the ignorance.

  39. 189

    truth writes:

    The demands of the CO2 response , brings with it, for individual countries, economic impacts that make it enormously more difficult to mitigate the other impacts—and will also necessarily restrict research into the whole climate picture—-and into renewables.

    I think Chris’s “What an alarmist attitude” response doesn’t begin to do justice to how wrong your comments are.

    For developed countries, the “response” can be performed on equipment replacement timeframes. This model of “replace existing, working coal plants with solar!” is, I think, wrong-headed. 2008 broke records for new wind and solar power installations in the developed world. For the developing world, distributed renewable generation (DRG) makes sense because many parts of the developing world don’t have a reliable grid to be concerned about breaking with DRG in the first place. Instead of megawatt diesel generators, wind and solar DRG is a very viable alternative — and it’s already being done in very small scales right now (okay, right 3 years ago). The problems, by and large, are not financial, but financing. The present economic environment makes that difficult, but it also presents opportunities for long term savings, which are more appealing in a down economic environment than a robust one.

    Turning back to the topic, biomass based generation provides an environmentally friendly solution to excessive fuel load which exists today. Bush wildfires waste potential fuel for human use and any solution (such as wood-gas production) which can capture the excess fuel load and convert it into a managed source of energy is a win-win.

  40. 190
    Ray Ladbury says:

    The ironically named “truth” claims “It’s just to say that a great deal has happened to the earth during that time besides CO2 emissions—and maybe the warming has more to do with those impacts.”

    Your position is utterly unscientific because 1)you propose no credible mechanism by which these changes would cause global impacts (especially in places where there is minimal human habitation–e.g. the polar regions) and 2)you propose no mechanism whereby the known contribution of CO2 to warming should magically cease at 280 ppmv (or ~287 Kelvin). Mechanisms matter. The consensus view has a mechanism. The fact that you don’t like the implications of that mechanism is not sufficient reason to abandon science.

  41. 191
    Rod B says:

    Jim Eager (174), I don’t and can’t lay any obligation on anybody to take any of my comments in any particular way. And try as you might, you can’t either.

  42. 192
    Rod B says:

    Ray (180), No one has ever completely explained the inherent physics behind why some gases have a linear marginal forcing rate, others have a log rate, still others a function of the square root; or why CO2 (a log function rate at current concentrations) is a function of the concentration to the 5.35th power, or why that exponential changes from time to time. All that is explained is numerical controlled lab observations with a physics hypothesis. This is reasonable to use in climatology as it seems in the right direction, and is all we have. But it ain’t “solid physics”, in the meaning FurryCH implied, no matter how loud and often you proclaim it to be.

  43. 193
    Rod B says:

    I’m amazed (though not perplexed) how you guys (FurryCatHerder, Kevin M., Chris O’Neill, at al) change people’s meanings and turn your head to some realities because (I guess) you fear it somehow attacks your dogma. “there is… much… unknown about many of the processes… ” says — now listen carefully — there is much unknown about many of the processes. There is nothing alarmist there; nothing about being daring or macho; nothing about concluding that we should do nothing; nothing about all’s well. Recognizing ignorance is not an attempt to either “protract” or “exaggerate” it. Proclaiming that ignorance doesn’t exist because you want to do this or that or believe this or that is blind faith.

  44. 194
    Rod B says:

    PS to be fair, some are in part looking at the situation through rose-colored glasses and confident in their easy solution.. They disagree (and are wrong IMO), but that aspect can’t be called “blind faith”.

  45. 195
    Hank Roberts says:

    Even if you ‘explain the inherent physics’ for any single molecule across the whole range of temperatures and pressures, you’ll only have begun. Next come interaction effects with two different molecules. Some may ‘cling’ at some orientations and more efficiently transfer energy when they interact for example.

    We have to remember all the cute little ball and stick models are just models; what’s there is a fuzzy cloud of probabilities interacting with others.

  46. 196
    Hank Roberts says:

    PS, Rod, when you drop comments like “nobody has completely explained ….” some folks don’t yet recognize you’re again fishing for people’s goats to add to your collection.

    Using red herrings as goat-bait gets people who mistake those remarks for comments on the science by someone who doesn’t understand it.

    Omniscience is a mental illness, not the culmination of scientific work.

    PS, for anyone claiming to have “completely explained” something, do remember this. It’s curable, I’m assured:

  47. 197


    I’m having a hard time understanding your problem with my saying the science is solid.

    The basic physics — CO2 molecules convert shortwave radiation to longwave radiation, which is more readily trapped in the atmosphere — is very simple. If you don’t understand that part, you’re not going to understand the rest.

    Quarreling about exponents and functions and all that other stuff doesn’t invalidate the basic nature of a molecule of CO2. Different gases absorb light at different wavelengths. The more a gas absorbs in the infrared, the more heat it traps. CO2 is a particularly efficient infrared “trap”, if you will. Because it traps infrared so effectively, even low quality heat energy is kept within the atmosphere by CO2.

    If you can find a way that the previous paragraph doesn’t imply that rising CO2 concentrations result in more trapped heat energy, you’ll have disproven CO2 induced climate change.

  48. 198
    Hank Roberts says:

    Human population doubles.
    Fish population declines far faster.

    Dave, do you foresee a diet of krill paste and a human population of twelve billion?

    “While the data show that ocean ecosystems still hold great ability to rebound, the current global trend projects the collapse of all species of wild seafood that are currently fished by the year 2050 (collapse is defined as 90 percent depletion)….”

    And we’re already on the 3rd or 4th tier of species “currently fished” — anyone remember when mature large cod, tuna, salmon and other top level fish were the main seafood found? Days long gone.

  49. 199
    Ray Ladbury says:

    Rod B., you post #192 is a prime example of why I say you haven’t understood the physics. First, the 5.35 is a coefficient determined by a fit. It is not an exponent of the logarithm. I simply do not understand why you persist in this interpretation. Have you read Ray Pierrehumbert’s Climate book, Chapter 4? It gives a pretty clear discussion of the radiative physics. Basically, the logarithmic dependence arises from the shape of the line in its wings. The reason you don’t have a logarithmic dependence in, say, CH4 is because the concentration is small enough that added CH4 still has a significant probability of absorbing in its peak. Please look over Raypierre’s explanation. It will keep you from posting drivel.

  50. 200
    Phil Zylstra says:

    Re 189’s comments on biomass burning and fuel loads: we need to be aware that the whole Miranda Devine argument suggesting that fuels can simply and easily be ‘removed’ has no broadscale basis. There are a range of case studies from various parts of the world showing reduced fire intensity in the few years following the introduction of prescribed fire, but there are very definite limits that need to be recognised.

    1) prescribed fire only has this effect for a limited time period. This ranges from 2 to 5 years on flat ground, and for less than a year on steeper slopes where most of the fire risk is located.
    2) the studies are very limited in their scope. While they reflect a broad and weak trend, there are forest types that respond to fire with a flush of fast-burning grasses in the first year and dense shrub & lignotuber regrowth in following years. Fuel ‘removal’ is not a panacea but a tool that suits the ecology of certain areas only.
    3) Fuel reduced areas provide reduction in fire intensity only under milder conditions. It is a fallacy to suggest that they would have made an iota of difference in the Victorian fires.

    These factors considered, let me make the point that the fuel is the forest, not just some component of it. If biomass harvesting is to provide some fuel reduction value relevant to the fires we are currently discussing, it will be by removing the forest itself. We cannot maintain forest as a carbon sink (as well as for all of its other ecosystem functions and biodiversity), while removing it for fuel reduction/energy production. Biomass burning needs to be a forestry operation separate to the management of the areas we’re discussing.

    While we have the bush we will have the fires, and while our temperatures increase we will have more of these and more severe. We cannot engineer this reality to suit our polluting lyfestyles. We’re sleeping in the bed we’ve made and we must adapt to this reality.