Fuel Loads Not Climate Change Are Making Bushfires More Severe, by David Evans. Bumped and highlights re-posted, because this is so topical.
People have been burning off to keep fuel loads low in Australia for thousands of years. From very long experience, we know that you have to burn off the undergrowth every ten years, and preferably every six. If you don’t, the inevitable fire is too destructive and too intense — a danger to life and property.
How do you start a fire in a fireplace? You stack up dry kindling around the logs and branches. The forests typical of most of Australia are like a fireplace. Building your house in among the trees is lovely, but building in a fireplace might get you killed.
Current fuel loads are now typically 30 tonnes per hectare in the forests of southeast Australia, compared to maybe 8 tonnes per hectare in the recent and ancient pasts. So fires burn hotter and longer. …
The Australian Government knows how much flammable material there is, and where it is:
The fuel load figures are hard to obtain, which is scandalous considering their central importance. There is also confusion over whether to include all material dropped by the trees, or just the material less than 6mm thick — it is mainly the finer material that contributes to the flame front.
Yes, the Australian Government does know roughly how much mulch and debris there is on the forest floor at any point in Australia. They estimate it for Australia’s carbon account, for the ongoing Kyoto Protocol. I know, because I built the system for the Australian Greenhouse Office (search on “FullCAM”). The Dept of Environment can estimate the mass of the trees, debris, and mulch on each 25 meter by 25 meter plot anywhere in Australia, using satellite data, plant data, weather and soil data, etc. Good enough for international accounting and estimating carbon emissions from the biosphere, it might be helpful in indicating where burn offs are needed most.
The aboriginals knew the truth:
Bill Gammage wrote an excellent book, The Biggest Estate on Earth: How Aborigines made Australia, which was awarded the Prime Minister’s Prize for Australian History and the Victorian Premier’s Literary Award in 2012. The first Europeans in Australia noted over and over that Australia looked like a country estate in England, like a park with open woodlands, extensive grassy patches, and abundant wildlife. Where Europeans prevented aborigines from tending their land it became overgrown, and the inevitable fires became dangerous and uncontrollable.
Particularly memorable is the account of driving a horse and carriage from Hobart to Launceston in the early 1800’s, before there were any roads, simply by driving along the grassy park underneath the tree canopies. Try doing that today through any bush in southern Australia. …
The blame is obvious:
Here is the burn-off and wild fire data for Western Australia:
A big lesson was learned in 1960 after some mega fires, and a regime of burn offs was instituted. Problem solved.
But then from the 1960s onward policy was increasingly influenced by people with romantic but unrealistic notions — the Greens. Their fantasy is that natural is best. They childishly figured that leaving forests alone and not burning or thinning was the most moral policy. It made them feel best.
Dangerous, foolish greens. The graph tells the story. Burn offs declined, fuel loads built up, then the fires started again in earnest.
To solve the problem, change the policies. And to do that, we probably need to replace our current incompetent ruling class. Incompetent? Well what would you call letting “unprecedented” huge blazes spring up, then blaming it on climate change? Fools or liars, take your pick.
See the entire article here.