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.

Phys.org says:

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 DipoleThe 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.78 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.79There 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 2019.85A 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.86SAM 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.87The 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.

More interesting.

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 graspimg 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 staement is, they then qualify it by suggesting that increased CO2 somehow miraculously affect 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 2.2.1.4, 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 freuency 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 no further evidence in support of the link to climate change as existed (risible as it was) in the months immediately after the wildfires. There is no definitive link between the south eastern Australia forest fires of 2019/20 and there is no good evidence to suggest they 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.

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August 26, 2020 at 12:06PM

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