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The raging Australian bush fires have been expansive and deadly. Country-wide, over 12 million acres have burned over the past few months, an area approaching twice the size of Massachusetts. The burnt areas in some regions rival or exceed individual fires of the past, such as the Black Friday fire of 1939, which burned about 5 million acres. As bad as the recent fires have been, note that various outlets in the U.S. have felt it necessary to exaggerate the size of the burnt area (also see here). And the season’s burnt area has not even approached the total for 1974-1975, when over 250 million acres burned.

So what causes these bush fires? Dry weather and plenty of fuel from dead vegetation create the hazard, of course. A spark is needed, as from lightning, an accident, an arsonist, or perhaps even a blistering sun, but warm temperatures are unnecessary. Nevertheless, the narrative we hear year-in and year-out is that global warming is to blame for wildfires. My commentary on the climate-change hubbub over the 2018 California fires is here. As for Australia’s fires, there is similarly ample evidence that climate change or warming has nothing to do with it. Rather, as in California, there is a pattern of mismanagement of forests and brush combined with population growth, accidents, and arson, and of course a dry spell. This dry spell has been severe, but the trend in Australia over the past 120 years has been toward more precipitation, not less, and the past 25 years have been relatively rainy. The rain comes with a downside, however: it encourages growth in vegetation, much of which dies every dry season, leaving plenty of fuel for fires. And the fuel has been accumulating.

Mike Shedlock at Mishtalk offers some pertinent observations. First, he quotes James Morrow in the Wall Street Journal:

Byzantine environmental restrictions prevent landholders from clearing scrub, brush and trees. State governments don’t do their part to reduce the fuel load in parks. Last November a former fire chief in Victoria slammed that state’s ‘minimalist approach’ to hazard-reduction burning in the off-season. That complaint is heard across the country.

Prescribed burns have been in decline and focused on areas adjacent to suburbs, leaving vast areas of accumulating fuel. This is a product of wrongheaded conservation efforts and resistance to CO2 emissions. These policymakers haven’t done favors for Australia or the world on either count. Shedlock reinforces this point with the following statement from Patrick Michaels and Myron Ebell:

Australia has been ready to explode for years. David Packham, former head of Australia’s National Rural Fire Research Centre, warned in a 2015 article in the Age that fire fuel levels had climbed to their most dangerous levels in thousands of years. He noted this was the result of ‘misguided green ideology.'”

Eucalyptus trees grow thickly in many fire-prone areas of Australia, and Shedlock says these trees act as a multiplier on the fire hazard. Yet these trees remain a favorite landscape feature for suburbians even in fire-prone areas. He quotes Marc Lallanilla in LiveScience:

Fallen eucalyptus leaves create dense carpets of flammable material, and the trees’ bark peels off in long streamers that drop to the ground, providing additional fuel that draws ground fires up into the leaves, creating massive, fast-spreading ‘crown fires’ in the upper story of eucalyptus forests. … Additionally, the eucalyptus oil that gives the trees their characteristic spicy fragrance is a flammable oil: This oil, combined with leaf litter and peeling bark during periods of dry, windy weather, can turn a small ground fire into a terrifying, explosive firestorm in a matter of minutes. That’s why eucalyptus trees — especially the blue gums (Eucalyptus globulus) that are common throughout New South Wales — are sometimes referred to wryly as ‘gasoline trees.’

The introduction of non-native invasive grasses has also been blamed for increasing the fuel load in the bush. And as incredible as it may seem, certain birds native to Australia are spreading bushfires by carrying and dropping burning sticks in grasslands to flush out prey. Birds are indeed tool users! The Whistling Kite and the Black Kite are sometimes called “arson raptors”, according to Leslie Eastman at this link.

The hypothesis that climate warming from CO2 emissions is the cause of the bushfires is undermined by all of the above. Then, of course, there are the arsonists and accidental fires. Over 180 people have been arrested for setting recent brushfires intentionally in New South Wales alone, and 103 others in Queensland. (Also see here.) Jim Steele reports that human ignitions account for 66% of bush fires, while just 11% are caused by lightning. Population growth has brought more people into close proximity with the bush, which increases the exposure of humans to fire danger and might well add to the number of accidents and potential arsonists. Obviously, human and avian arson, and accidents, are not within the line of causation that climate alarmists have in mind.

Roy Spencer addresses some of the inconsistencies in the claimed link between climate warming and the Australian bushfires. First, of course, is the trend in rainfall. Climate models based on CO2 forcings predict no long-term trend in Australia’s rainfall, but again, rainfall has increased in Australia during the era of accelerated forcings. Interestingly, the fires of 1974-75 occurred during a period that was quite rainy, but that rain might have added so much to the annual vegetation cycle that it exacerbated the effect of dry season. Temperatures in Australia were quite warm in 2019, but the climate models cannot account for that variation, especially as Australian temperatures are subject to high variability from year-to-year. It’s been hotter before, though the temperature records in Australia have been subject to some controversial “editing”. Finally, Spencer notes that global wildfire activity has been in decline for many years, despite the mild warming we’ve experienced over the past 50 years (also see here).

Australia has bush fires every year, and this year has been particularly bad, but it might not reach the proportions of the fires in 1974-75. The causes are: poor burn management practices, or sometimes neglect and no burn management at all, allowing dead vegetation to accumulate to dangerous levels; arson, which has been implicated in a large number of fires this year; and 2019 was a very dry year. The contention that global warming or climate change is responsible for these bush fires is a dangerous distraction from reforms that can minimize fire hazards in the future.

For additional reading of interest, see Australia Fires … and Misfires” by Willis Eschenbach and The Mathematics of Connectivity and Bush Fires: A Note From David Ward” a post from Jennifer Marohasy’s blog.