New South Wales Bushfires & Climate Change – The Final Report
The New South Wales Government has published its final report on the devastating forest fires of 2019/20, which destroyed 5.5 million hectares (21,236 square miles) of outback wilderness in South Eastern Australia, killing or displacing nearly 3 billion animals in the process, destroying thousands of homes and claiming many human lives too.
Climate change is mentioned in the report, so you can guess of course that the media has leapt on it immediately to claim climate change ‘clearly’ fuelled Australia bushfires, that climate change ‘clearly played a role’ in conditions that led up to Australia’s 2019-2020 fires and that Australia should should expect “worse” in the years to come (because one of the main causes was climate change).
The Graun typically goes into alarmist overdrive:
The inquiry found climate change and rising greenhouse gas emissions “clearly played a role in the conditions that led up to the fires and in the unrelenting conditions that supported the fires to spread” but climate change alone “does not explain everything that happened”.
The report said that extreme conditions of the kind seen last summer are likely to happen again and dangerous fires will become more frequent, meaning state and local authorities would need to do more to prepare.
Former fire chiefs who have called for an urgent response from governments to the climate crisis said the findings of the review supported their position.
During the fire season, former fire chiefs from several states said their advice to the Morrison government that the climate crisis was making fire seasons worse had been ignored.
“The NSW bushfire inquiry has echoed what the experts have said all along: climate change is driving longer, hotter and more dangerous bushfire seasons, including our Black Summer,” said Greg Mullins, a former fire and NSW rescue commissioner.
Mullins said Australia was in a new era of climate-driven bushfires in which fires were more likely to develop dangerous pyroconvection events. He said governments needed to do more to address the underlying cause.
“Immediate steps the NSW state government can take to drive down emissions include: rejecting all new coal and gas projects like Santos’ Narrabri project, and accelerating its net-zero plan to create clean, long-term jobs in sectors like renewable energy,” he said.
Australia’s devastating 2019-2020 bushfires were “clearly” fuelled by climate change, a government inquiry reported Tuesday following some of the largest forest fires ever recorded worldwide.
The text included dozens of recommendations and featured a blunt rebuke of those who insisted the fires were nothing to do with climate change.
“Climate change as a result of increased greenhouse gas emissions clearly played a role in the conditions that lead up to the fires and in the unrelenting conditions that supported the fires to spread,” it read.
Yeah, sock it to the climate deniers, like me, who insisted that climate change had very little to do with the fires, that they were overwhelmingly the result of a confluence of extreme weather and natural variability driven by natural climate modes affecting that region.
Doom, gloom and more doom. As if the People’s Republic of Australia hasn’t got enough on its plate at the moment, with Dictator Dan wanting to lock down Victorian citizens for another year because eight people died on Tuesday, seven of them in aged care. Covid Zero policy they call it. It means if you put your bins out after 8pm, you get cops threatening to wave a gun in your face and enter your home without a search warrant – because you’re putting lives at risk. They’ve also got the Net Zero climate crisis fanatics claiming that Aussies can prevent their wilderness from going up in smoke in future by adopting ‘clean energy’, by giving up air conditioning, cars and gas barbies whilst getting used to constant blackouts. I suspect those twin political strategies are not a hundred miles apart. Covid zero looks a lot like entry level net zero; short, sharp and very nasty with net zero being the long tail ‘green recovery’. Tucker Carlson seems to think there’s a link.
As usual with the media, if you want the real story and if you want to know what part climate change might really have played in the Australian wildfires, you have to go the original report, in this case a massive 466 page document which would probably take many hours to read and digest properly. I’ve just skimmed the important parts which talk about the direct causes of and the corresponding host of contributing factors to the wildfires.
Chapter 2 of the Report is titled ‘CAUSES AND FACTORS CONTRIBUTING TO 2019-20 BUSH FIRE SEASON’.
This Chapter addresses the first component of the Terms of Reference which asks the Inquiry to consider and report on “the causes of, and factors contributing to, the frequency, intensity, timing and location of, bushfires in NSW in the 2019-20 bushfire season including consideration of any role of weather, drought, climate change, fuel loads and human activity”.
Fair enough. This is what the authors say about the role played by climate change:
The Terms of Reference specifically ask the Inquiry to comment on the role of climate change in contributing to the 2019-20 bush fire season. Early on, the Inquiry consulted Professor Andy Pitman AO from the University of NSW and Director of the Australian Research Council Centre of Excellence for Climate Extremes. Professor Pitman explained that while climate change, in particular increases in temperature that have been attributed to increased carbon dioxide emissions, is clearly a contributing factor to the type of bush fires seen in the 2019-20 season, it does not provide the full explanation for why they were so bad. For example, it cannot be said with certainty that the extent and severity of the drought leading into the fire season was caused by climate change, but it is also not possible with the available evidence to say that it wasn’t. In this Chapter we tease apart the causal and contributing factors for these fires with a view both to understanding what we do and do not know in this area and, as discussed in later Chapters, to informing practice in preparing for and responding to fires of this kind.As Professor David Bowman from the University of Tasmania told the Inquiry, there was a ‘constellation of factors’ that together contributed to an extremely unusual bush fire season.
Hmm, not really much there to get your teeth into. Bit of a ‘might have, might not have’ cop out really. But the report goes into more detail below:
As the BoM informed the Inquiry, there are several climate variables that increase the risk of a bad fire season. Two phenomena – or modes of climate variability – in particular have been highlighted as key contributors to the intensifying dry conditions in the lead-up to the 2019-20 fire season: a strong and long-lived positive Indian Ocean Dipole and a negative Southern Annular Mode associated with a sudden stratospheric warming event.
Positive Indian Ocean Dipole The Indian Ocean Dipole (IOD) is a key driver of Australia’s climate. The IOD refers to changes in sea surface temperatures between the western and eastern Indian Ocean, which influence temperatures and rainfall patterns in Australia. A positive IOD tends to bring drier and warmer than average conditions to central and south-eastern Australia during winter and spring, and the IOD in its negative phase typically brings wetter than average conditions. There was a strong positive, relatively long-lived Indian Ocean Dipole (IOD) from May-December 2019. The IOD was also positive in 2018, and at near record intensity in 2019
While the IOD is certainly not the direct cause of the 2019-20 fires, it is quite possible that it played a role in preparing the landscape for fire.
Nothing we didn’t already know.
There was a combination of negative Southern Annular Mode (SAM) and a Sudden Stratospheric Warming event from October to December 2019. A negative SAM is a large-scale mode of weather and climate variability associated with a shift in the atmospheric pressure patterns across the Southern Hemisphere. A Sudden Stratospheric Warming is a more irregular phenomenon where temperatures in the stratosphere above the south pole heat rapidly. The effect of both these events, individually, is to push the westerly winds that circle the Antarctic continent over the Southern Ocean further towards the equator. In general, this leads to a greater predominance of westerly winds over the southern half of Australia. When these two phenomena are combined, they can cause a prolonged northward shift in the belt of westerly winds. A negative SAM event alone usually only lasts a couple of weeks. SAM in a negative phase in spring and summer generally leads to a decrease in rainfall and increase in westerly winds from inland Australia. These conditions can greatly increase fire danger ratings in NSW and south-east Queensland. The Sudden Stratospheric Warming event that began in August 2019 was the strongest in the southern hemisphere since 2002, and contributed to a prolonged negative SAM event lasting from October to December 2019 inclusive. The resulting predominance of westerly winds over Australia throughout spring, combined with a very dry interior of eastern Australia as a result of protracted drought, played a crucial role in further drying the landscape and increasing fire danger over eastern regions of NSW. The BoM advised that the two phenomena combined “produced an intense period of low rainfall and above average temperatures with consecutive heatwaves over parts of eastern Australia in late 2019”. Lim, Hendon, Boschat, Hudson, Thompson, Dowdy and Arblaster (2019) have shown that the likelihood of conditions that contribute to fire risk in central NSW was significantly higher in years with a Sudden Stratospheric Warming event (including the previous strongest event in 2002). Further, Harris and Lucas (2019) have also shown that, for the central coast, the negative SAM is the primary influence of elevated fire weather (as measured by the Forest Fire Danger Index (FFDI)) in late winter and spring, and has a greater influence in that region than the IOD (or the El Niño/Southern Oscillation).
However, the BoM explained that, when multiple phenomena that are associated with drier conditions across eastern Australia are coincident (or in phase), they can reinforce the effects.
Finally, we have the influence of ENSO variability:
In addition to the IOD and the SAM, the El Niño/Southern Oscillation (ENSO) is a third key climate phenomenon that influences rainfall in NSW. As well as experiencing the climate modes that are associated with below average rainfall, we were also (and still are) experiencing a long period of time without seeing the climate modes that are associated with wetter than average conditions – a negative IOD or a La Niña – both of which are associated with wetter conditions in south-east Australia. In the lead-up to the bush fires, the El Niño/Southern Oscillation (ENSO) was neutral – which means we were not experiencing either El Niño (generally drier) or La Niña (generally wetter) conditions. So, in the lead-up to the 2019 fires, we experienced climatic drivers that increase likelihood of dry conditions (i.e. the positive IOD and negative SAM), as well as a long period of time since a negative IOD phase or a La Niña which would be associated with wetter conditions. As observed by Professor Andy Pitman “neither the IOD or ENSO are hard core predictors of Australian rainfall but they do weight the dice to change the probability of significant rainfall”
So this tells us that we had a pretty unique confluence of natural climate drivers which combined to create the perfect weather conditions for the extreme wildfires which ravaged south eastern Australia in summer 2019/20. Taken together, they more than adequately explain the conditions which occurred at the time. We don’t really need ‘climate change’ but of course, they need climate change because if natural climate variability and weather alone can explain a natural disaster, then they don’t really have a ‘climate crisis’ and they’ve got to have a visible climate crisis to justify ‘climate action’.
So then they roll out the usual spiel about ‘long term trends’:
The variables described in the previous sections were acting on top of longer-term observed background trends of higher temperatures in Australia and reduced cool season rainfall. The BoM indicates that long-term trends in key climate variables (rainfall and temperature) have increased the tendency for dry and warm winter and spring conditions over south-east Australia. CSIRO reports that Australian’s mean annual temperature has increased by almost 1.5C since 1850, along with reduced rainfall across the southern half of the continent. This warming is predominantly due to changes in climate associated with increased greenhouse gases in the atmosphere. The State of the Climate 2018 report shows a decline of around 11% in April-October rainfall in the south-east of Australia since the late 1990s. Overall higher temperatures acting over a long time period (not just during the fires) also have the effect of increasing the growing season due to warmer winters with clearer skies, which all increases evaporation. This increases the risk that we begin spring with a drier landscape. These trends, combined with the positive IOD and negative SAM in the lead-up to the 2019-20 fire season, provided the antecedent conditions for very high fire danger by drying out the landscape.
Spot the sleight of hand? The only really long term trend is the 1.5C increase in average temperature since 1850. Somehow, that’s supposed to have played a significant part in the wildfires is it? But then they talk about a decline of rainfall since the 1990s which also gets blamed on demon CO2 but could equally as likely be part of a long term natural climate cycle. All they’ve got really is the rise in average temperature since 1850 and blaming all of that on man-made climate change is also not scientifically very justifiable.
The rest of Chapter 2 explains how it was the particular weather conditions during 2019/20 which drove the peculiar severity of the wildfires, making them very difficult to contain, but then they have to finish with a climate change flourish, which is basically just poorly evidenced and unfocused pseudoscientific waffle. This is where the idiot MSM get most of their alarmist climate change spiel from as well.
Fires will not be of the scale and type seen in the 2019-20 season every year. However, a repeat of fires of that scale, or worse, is a realistic prospect. Indeed, we should expect to see serious fires more frequently. For a fire season like 2019-20 to occur again, multiple risk factors need to combine in the right way and there are some key drivers that we need to be watching closely. Unfortunately, there are several factors ‘loading the dice’ to increase the probability of these things combining in the right way for serious fires to become more frequent in the future.
It’s those really technical climate science terms in action again: ‘we should expect worse/more frequent such events‘ and ‘the dice are being loaded‘. Not forgetting that old chestnut ‘is consistent with climate change projections‘:
Some of the important contributing factors can be linked to changes in climatic conditions associated with increased carbon dioxide emissions. The higher concentrations of carbon dioxide in the atmosphere affect the risk of some conditions conducive to fire occurring.
In general, much of what is being observed in south-eastern Australia is consistent with climate change projections. These projections predict that many of these trends will continue.
Then they start really grasping at straws, claiming that an average warming of 1.5C over 170 years has “dramatically increased” the chance of heatwaves. Perhaps realising how utterly stupid this statement is, they then qualify it by suggesting that increased CO2 somehow miraculously affects dynamic weather patterns too, which are the direct causes of heatwaves:
The average warming noted above dramatically increases the risk of heatwaves. Successive heatwaves were a significant contributing factor to the 2019-20 bush fire season. Multiple projections indicate that we should expect to see increased heatwave intensity, duration and frequency in NSW and ACT. In part this is associated with the average warming, but it also appears related to how warming is influencing weather patterns including southerly changes. We need to know a lot more about how warming in the averages influences weather patterns associated with fire over NSW.
They even have a stab at trying to implicate CO2 molecules in changing trends in IOD, ENSO and SAM, the three major natural climate modes which affect the Australian continent:
As explained in section 188.8.131.52, some large-scale climate modes influence rainfall in Australian and NSW – IOD, ENSO and SAM. It is also possible for these modes of variability to occur at the same time, intensifying conditions that lead to drying. Some initial emerging research suggests that intensity and/or frequency could be increasing for modes of variability that contribute to drier conditions and therefore increased fire risk in NSW.
Then they say:
The trend of more extreme fire seasons and large fires in Australia appears to be part of an emerging trend globally, as shown in the following examples.
Which is strange, because, in November 2018 Abatzoglou et al released a study on precisely this issue: ‘Global Emergence of Anthropogenic Climate Change in Fire Weather Indices’. What they found was that in Australia, natural variability was too high to conclude that anthropogenic climate change was affecting the frequency and intensity of wildfires; the signal to noise ratio was just too high:
Emergence is a function of the signal of change and persistence subject to internal climate variability as com-pared to the natural variability of the baseline period. We deconstruct the primary drivers of emergence in FWI metrics using two approaches.
A majority of terrestrial surfaces show statistically significant increases in all metrics (ttest;p<0.05) for a majority of models by mid-century, including a doubling of FWI95d versus the historical baseline for 31% of burnable global lands. For comparison, the multimodel median standard deviation calculated over the baseline period shows relatively high interannual variability in FWI metrics across portions of Australia which impede emergence based on a signal-to-noise ratio (Figure S5)
In summary then, this massive new report, informative as it is in many respects on issues which I have not touched on here, has nothing further to say in support of the alleged link to climate change being reported on in the months immediately after the wildfires. There is no definitive link between climate change and the south eastern Australia forest fires of 2019/20 and there is no good evidence to suggest that wildfires will get worse with increasing GHG emissions. That does not stop the climate alarmist fake news media from reporting that ‘climate change clearly played a role’ though, implying that it played a significant role. It almost certainly did not. That should be the end of the story. It will not be.
Paul Homewood has picked up the similar theme with the California wildfires:
“California’s fires should indeed serve as a warning to the public, but not that climate change is causing the apocalypse. Rather, it should serve as a warning that mainstream news reporters and California’s politicians cannot be trusted to tell the truth about climate change and fires.”
As usual, it is the totally unscrupulous fake news alarmist MSM which is pushing the climate change apocalyptic narrrative and making it up as they go along, regardless of the facts.
“Why do activist journalists and politicians get California’s fires so wrong?
Part of the reason is their determination to blame climate change for everything.”
“If all you have is a hammer everything looks like a nail,” noted Keeley. “If all you study is climate change than everything looks like it is caused by climate change. Every climate change research center finds climate is a problem. They are trying to find climate as the explanation.”
Paul’s post is based on this article by Michael Shellenberger in Forbes, which is well worth a read to see how politicians and journalists distort facts in order to exploit natural disasters, particularly heat waves and wildfires, but no doubt they’ll be hard at work exploiting the latest hurricane landfall too.
As I have said before, the full causal story requires both an understanding of the likelihood something could happen without the posited cause (the probability of necessity) and the likelihood that it would still not happen even with the posited cause (the probability of sufficiency). Here we have a substantial report that identifies the many factors that bear upon such assessments. But call me old-fashioned; unless one is prepared to quantify the two probabilities, one is just waving arms. As you point out, the MSM tend to focus upon the probability of necessity, simply because it is non-zero with respect to AGW. But how many pundits are prepared to quantify it? What is, for example, the FAR for the 2019/20 bushfire season? Phrases such as ‘the dice are loaded’ are true and emotive but fall a long way short of being scientific unless one is prepared to say by how much in terms of the probability of necessity. The same goes for the probability of sufficiency. The report mentions enough extraneous causes to suggest that this must be low. But how low? Is it still large enough to be of concern? Yes, say the MSM, but is anyone prepared to back this up with numbers that have not just been plucked out of the air?
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John, the only attribution study done on the 2019/20 bushfires is the WWA study which you posted about a while ago. As I pointed out at the time, they did three separate attribution studies: seven day heat index, drought and the Fire Weather Index. They found no anthropogenic influence re. drought, but did find an influence on the Fire Weather Index, but this is perhaps not surprising because the Canadian FWI has just a short duration drought component of 1 month, whereas the extreme dryness of the fuel in south eastern Australia was caused by prolonged drought over many months. Effectively, they removed the component of the fire index which would have interfered with the attribution to AGW – prolonged drought.
They didn’t even have a lot of success in definitively attributing the observed increase in temperature extremes since 1910 to anthropogenic climate change either. All in all, the attempted attribution of the forest fires to climate change was a bit of a damp squib.
“The discrepancy implies that we cannot give quantitative results for the attribution of heat extremes in southeastern Australia, as the heat extremes in the climate models are too different from the observed heat extremes. This affects especially the changein probability, which depends strongly on the variability.
Before 1950 the global mean temperature was affected as much by volcanic and other natural forcings forcings as it was by greenhouse gases, with possibly different effects from the anthropogenic forcings on circulation. We therefore also show a figure with results from 1950, Fig. 7, for which more consistent observations are available, noting that this is a better estimate of the greenhouse-gas driven trend with better observations than the whole period since 1900. There are two interpretations of this discrepancy: either the observations are influenced by another driver than anthropogenic climate change that caused the rapid rise in extreme temperatures or the models have problems simulating the response of external forcing on these events and their related processes (or a combination of these two).
Observations show that a heatwave as rare as observed in 2019/20 would have been 1 to 2◦C cooler at the beginning of the 20th century. Similarly, a heatwave of this intensity would have been less likely by a factor of about 10 in the climate around 1900. While eight climate models simulate increasing temperature trends they all have some limitations for simulating heat extremes: the variability is in general too high and the trend in these heat extremes is only 1◦C. We can therefore only conclude that anthropogenic climate change has made a hot week like the one in December 2019 more likely by at least a factor of two. Given the larger trend in observations in the models we suspect that climate models underestimate the trend due to climatechange. Coupled with the high variability of the models, the increase in the likelihood of such an event to occur is likely much higher than the models simulate.”
The trend in the observations was larger than the trend in the models. They can’t explain this so they assume the models merely underestimate the change in extremes and therefore the ‘real’ impact of anthropogenic climate change must be higher! Now, it strikes me that a significant factor influencing temperature extreme is in fact humidity. If you have extreme aridity, the ground and the air above are able to heat much faster and subsequently attain a greater maximum during the day. Furthermore, if you have particularly intense, uninterrupted solar insolation over days/weeks, this also contributes to the attainment of high maximum temperatures. Humidity and exceptionally clear skies are of course functions of weather and meteorological conditions, not a function of any long term secular rise in average temperature. So an equally likely explanation for the observed trend being greater than the modeled trend is that the models do not adequately capture long term natural variability and changing atmospheric dynamics.
Maybe CO2 allows plants to grow larger and this increases the amount of wood and leaves. The other question I would ask is whether the burnt areas are recovering.
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Yeh, I seem to remember taking a quick look at that study. Your latest comment serves as a useful reminder. It reminds me that they could only quantify an FAR of the extreme heat event with respect to AGW but they were somewhat flummoxed when it came to the probability of sufficiency. Furthermore, even an FAR of the actual bushfire event was beyond them, and for very good reasons. So I guess it was obtuse of me to have asked the question. I already knew enough to know what the answer would be 🙂
Fernando, I don’t know about CO2 but the report does point out that the longer growing season experienced in recent years may have contributed to increased undergrowth. Last I read, some areas are recovering remarkably quicly.
Extreme weather attribution science is now like: ‘Meh, heatwaves are soooo boring, don’t fink I’ll bovver doing an attribution study cos it’s bleedin’ obvious it was climate change wot dunnit‘.
“The field of climate attribution is still relatively young, having started up in earnest only in 2004, the year after a European heatwave killed 70,000 people. But the science has progressed rapidly. Heatwaves in particular are less and less interesting for researchers. Friederike Otto, a University of Oxford climate researcher and organizer of the World Weather Attribution initiative, said she doesn’t think they’ll bother investigating the recent California heat from a climate change perspective. “The evidence is so strong already,” she said.
Climate science has ceased to be science; in fact they’re not even bothering with the charade of doing what they call science anymore; it’s just ‘Yeah, that’s exactly what we expect, not going to waste time ‘proving’ it‘.
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My understanding of Australian ecology is very limited, but I suspect bush fires are part of the natural cycle. I also suspect that human activity decreases their frequency through management of the vegetation, but this then leads to a build-up over time of dead flammable material. So when the fires do get a hold they are bigger. It is also noticeable that most of these fires were in the most populous, cooler states (NSW, Victoria and the southern coast of WA), not the hotter ones. This suggests they are more a product of urbanization and intensive agriculture than climate change.
I would also point out that the claim that temperatures in Australia (and particularly in NSW and Victoria) were much lower in 1900 than they are today is false. They were practically the same. The data is on my blog at:
Temperatures in Australia (and many other parts of the Southern Hemisphere) declined before 1950 and then rebounded. There is also some evidence of self-similarity in the temperature data with a fractal dimension of 0.25. See here:
This has implications for the amount of natural variability that is observed in the long-term temperature record. It is much more than you might expect.
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“All they’ve got really is the rise in average temperature since 1850 and blaming all of that on man-made climate change is also not scientifically very justifiable.”
It is not justifiable because it is not true. Temperatures in Australia (particularly in NSW and Victoria) were just as high in 1850-1890 as they are now.
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Apologies for the delay in publishing your comment Slarty.
The plague was made worse because according to prophecy, God’s wrath was kindled by the sinful people and their faithlessness.
Jaime, this article is the last climate contribution you wrote about the science (and nonscience) of climate change. Might I enquire why? It’s not that the topic has gone into the doldrums as any inspection of WUWT will show. You have delved into other matters, even more controversial and Cliscep has lost its science rudder. Yet I see this morning you have written a piece about cold spells in Eastern USA being attributed to Climate Change in your own website. This, I venture, would previously have been an admired piece of writing within Cliscep. Why have you abandoned us? Please return to beat the heathen climate change proselytisers at their own game. Cliscep is much poorer in the absence of your climate science contributions.
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Alan, I haven’t abandoned you. You will note that I am also writing about other subjects on my own blog which, if I were to publish here, would probably attract the kind of criticisms and controversy which have dogged some of my non-climate related articles over the last 10 months. Richard even went to the bother of publishing an article which specifically mocked me in that regard. So, for completeness, and intellectual freedom, and to avoid the unjustified, increasingly absurd and somewhat personal attacks from Richard, who is one of the co-founders of Cliscep, I have decided to publish my ideas elsewhere. However, I’ll be quite happy to re-publish climate change related material on this blog if that’s what you and others would like. I also miss Paul. What happened to Paul Matthews I wonder? It hasn’t been the same here without his guiding presence.
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