Is this historically different from previous instances? https://en.wikipedia.org/wiki/Bushfires_in_Australia
Just skimming wikipedia and there are a bunch of bushfires that were bigger than this instance, and bushfires seem pretty common there
Just skimming wikipedia and there are a bunch of bushfires that were bigger than this instance, and bushfires seem pretty common there
Keep in mind, Australia is huge and has different climates.
While this isn't the biggest fire of all Australia, it is the biggest fire of that region in history by ~10x (according to that wikipedia link).
This is highly unusual.
And as a result of being in populated areas, it has done the most dollars of damage of any fire. This is what climate change advocates are pointing to: increased fires in areas that normally do not have them.
Previous severe big bushfires started much later:
infographic: https://ichef.bbci.co.uk/news/660/cpsprodpb/ECEF/production/...
January and February are the hottest. December and March have similar temperatures. The seasonal weather and sea temperatures have delay relative to sun.
As an anecdote.. We live in Sydney. My wife was talking to her father who was being evacuated from his town in Northern California due to fire. We could smell smoke in Sydney already, despite being in the opposite season.
It's a bit like 5 hurricanes hitting Florida in one summer. Aren't hurricanes normal in Florida?
Except if 3 of those hurricanes arrived before hurricane season.
So while recognising, what I believe is you're ironic phrasing, I'm addressing what I think will be the un-ironic reading others will take, you good with that.
Yes fire is a normal part of Australian ecosystems, and it is unknown whether this spread with Eucalyptus trees or whether Eucalyptus trees spread with humans using fire.
But :
The Australian climate is getting hotter:
http://www.bom.gov.au/climate/current/month/aus/summary.shtm...
'The national December mean temperature, 3.21 °C above average, surpassed the previous December record set in 2018 by more than a full degree.'
British conquest and subsequent settlement has ended traditional indigenous fire practices in most part of the country.
https://en.wikipedia.org/wiki/Fire-stick_farming
Which means that the fuel load are not reduced by smaller cooler burns below levels that would feed a catastrophic fires.
https://www.science.org.au/curious/earth-environment/bushfir...
Partisan politics has made it very difficult for many Australians to look directly at these topics. So while fire, is a terrifying but not unexpected feature of living in Australia, the scale of this year's fires are a unique horror that I believe will push enough Australians to engage with that difficulty.
I think we are going to see fast significant shifts in political discussion from this, that both the emotive calls to action, and populist denials or diminishment will we perceived as a distraction from direct sober engagement of an existential threat.
( As I first typed this I accidentally capitalised that as Australian Ecosystems, because I once worked for a company by that name that did environmental work, including controlled burning)
Other examples of Australian plants that are adapted to bushfires to the degree that they require them to propagate are found in the genus Banksia [2]. Together with the genus Eucalyptus they comprise hundreds of plant species[3]. These aren't the only pyrophytic plants[3] that require fires. For example, Melaleuca quinquenervia is another pyrophytic plant of Australia [4].
Wikipedia says this of the Eucalyptus:
> Most species of Eucalyptus are native to Australia, and every state and territory has representative species. About three-quarters of Australian forests are eucalypt forests. Wildfire is a feature of the Australian landscape and many eucalypt species are adapted to fire, and resprout after fire or have seeds which survive fire.
Eucalyptus trees survive fire so they can be classified as a pyrophytic plant; they benefit from fires that destroy competitive plants. The Giant Sequoia trees of the US also survive fires and are are considered pyrophytes. However some plants are considered to be active pyrophtes because they encourage fires or the spread of fires. The Eucalyptus is an active pyrophyte because it produces inflammable oils.
The carniverous Byblis genus of plants and cogongrass are other examples of fire adapted plants found in Australia.
[1] https://en.wikipedia.org/wiki/Eucalyptus
[2] https://en.wikipedia.org/wiki/Banksia
[3] https://www.britannica.com/list/5-amazing-adaptations-of-pyr...
1. Bushfires may be more frequent in some parts of Australia than others. So two bushfires of equal size, but occuring in different regions, may not necessarily be equally common.
2. The list on Wikipedia is referring to final surface burned, after the fire is contained, or has burned out. However the 1.5M Acre figure mentioned here seems to be only the current surface burned - presumably it will continue to expand and burn more.
So today's fires are weak ammunition for reallocations of public resources towards climate change efforts, compared to existing arguments that can't gain consensus. I can see how it isn't budging consensus.
edit: removed bad news regarding arson
24 people have been charged over alleged deliberately-lit bushfires
53 people have had legal actions for allegedly failing to comply with a total fire ban, and
47 people have had legal actions for allegedly discarding a lighted cigarette or match on land.
Source: NSW police official website
A reasonable assumption might be that fires in unpopulated areas in central Australia were probably not arson (no people there to set them) and these are the largest fires (no people there to fight them).
But rather early for any broad conclusions. All we can say is - there's been some arson but we lack the context or details to really understand the relative importance. Currently arson doesn't seem like a major factor and it is probably over represented in densely populated NSW relative to the rest of the country.
I would say there's little evidence to support a hypothesis of an "unusual arson wave".
The authorities (don't know if this is RFS or police in this case) seem to pretty confidently attribute fires to causes for the most part. The percentage attributed to arson is lowish but disturbing (20%?).
I imagine lightning strikes and ember spread from existing fires are fairly easy to diagnose. I'm not sure how you tell "fires spread from sparks from roadway incidents" from "arson" but I'm not an expert.
Weather patterns (hot and dry summer) create the conditions for a fire, an arsonist merely provides the ignition source. In the right conditions a single errant spark from a power tool can set off a giant bushfire. Or an arsonist with a single match.