So, about those Australian fires….
It’s high time I wrote a post about them, as the disaster constitutes one of the most dramatic climate-related catastrophes today, and it’s likely to keep getting worse for a while, yet. While some people have complained that climate change didn’t start the fires, that’s a bit like saying that jumping off a sky-scraper wouldn’t kill you–technically true, but more deeply false (with the sky-scraper, it’s the sudden stop at the end that gets you). Climate change helped create the circumstance where hitherto-unheard-of fires are possible.
I’ve written before about the links between climate change and fire with respect to California. The situation in Australia is broadly similar.
I’m not going to rewrite those articles with an Australian focus–other people are covering the topic already. What I want to know is how bad are these fires, other than “really bad”? How big are they, really? It’s easy enough to look up the numbers of acres burned, number of people killed, and so forth, but it’s hard to really put that information in context. How much of Australia burns in a typical year? How well will Australia be able to recover, ecologically or economically? Is anything being lost that can’t be regained?
Putting the Australian Fires in Context
There are several questions I want answers to:
- How much of Australia is burning or has burned?
- How much damage has been done to the specific biomes involved?
- How do the 2019/2020 fires compare to historical fires in Australia, both in extent and in intensity?
- In what ways besides climate change have human activities made the fires worse?
- How well can Australia recover, either ecologically or economically?
- Will Australia have more fires like this in the future?
- Could other countries see similar disasters in the near future?
Some of those questions are easy to find answers for, others would require a major research project if they could be answered at all. For now, let’s just explore some of these issues.
How Bad Are the Fires?
Several questions involve the severity of the current disaster. As I said, it’s easy to look up the acreage burned, and it is just as easy to look up maps that show the extent of the fires relative to Australia’s land mass overall. These are pretty arresting images, but they don’t tell the whole story.
The issue is that the part of Australia that is not on fire is mostly uninhabited–both flammable vegetation and humans cluster in the well-watered coastal regions. If we could calculate the proportion of Australia’s inhabited area that has burned over the past year, the resulting fraction would be even more arresting and give outsiders a much more accurate picture of what Australians are going through right now.
Unfortunately, I have not been able to find a figure for the size of Australia’s inhabited area. In fairness, it is difficult to define such an area, because there is no black-and-white distinction between “inhabited” and “uninhabited.” Rather, the population just gets thinner and thinner.
At the moment, the best I can do is eyeball a comparison between a map of Australia’s population distribution and the various maps of the fires (here’s one; an image of the cumulative light of a month of fires)
Those well-watered coastal areas are also ecologically distinct from the arid interior. A map of Australia’s major biomes (a biome is an ecologically defined region) shows that the region where many of the fires have been clustered are also within a relatively small biome, the Temperate Broadleaf and Mixed Forest. Another cluster of fires overlaps with much of an even smaller biome, the Tropical and Subtropical Moist Broadleaf Forests. As you’ll see if you click on the links, I have not actually found a map that shows biomes and fires, I’m doing more eyeball comparisons. To my eyeball, it looks like a significant chunk of both biomes must have gone up in smoke this year.
Wildfire is usually not the disaster it appears to be, since the burned-over areas are re-colonized with vegetation and animals from unburned areas–and while the burn zone is recovering, it provides habitat to various species that specialize in the different stages of recovery. However, if an entire biome were to burn completely, recovery would not be possible because the organisms able to live in that biome would all be dead–and most of them would be extinct, since it is unusual for a species to occupy multiple, radically different habitats. Real wildfires seldom burn completely (there are usually un-burned pockets, and the less-intense fires spare the roots of plants, burrowing animals, and even some trees) but disaster need not be complete to be decisive–and Australia has already suffered widespread deforestation and habitat fragmentation. There’s not a lot left to burn.
Could we be witnessing the loss of two biomes right now?
Are the Fires a Cause or an Effect?
Can Australia recover? I have found several articles on economic and cultural recovery, and while everyone seems to acknowledge that recovery will be difficult, no one seems to doubt it will happen. There is some worry that there may indeed be permanent ecological change.
What I wonder is whether the permanent change has already happened. In other words, is fire (exacerbated by climate change) the agent of an ecological shift, or merely a symptom of a shift that has already occurred?
To choose an example of what I mean that is closer to my home, the Southwest of the United States is famous for its deserts, but actually much of the region is dry forest dominated by several species of pines. There are those who think much of that forest will be lost with climate change–and in fact, some parts of it have been lost already. One might be tempted to think the loss will be gradual, since climate change, while very fast, is gradual (that is, it is more like a gradient than a step), but that’s unlikely.
Living systems, whether individual organisms or whole ecosystems, resist change the same way a spinning top is harder to push over than it looks like it should be. Dying people can sometimes hold their own far into grave illnesses, looking and sounding almost normal until very close to the end. Unfortunately, I’ve seen this recently, as those who know me are aware. Dying forests work much the same way, the trees hanging on in the face of heat and drought that isn’t really drought but rather a new regional normal. Then there is a fire or an infestation of bark beetles or both. The beetles are not new, but in the past the trees could fight the beetles off with sticky sap. In a bad drought, the trees can’t make enough sap. There are more beetles, too, after warm winters. I’ve seen this–almost twenty years ago, I watched almost every pinyon pine in one forested area die from beetles in just a few months. That year I saw pictures of places where similar beetles had killed whole hillsides of ponderosa pines, turning them a pretty red-brown that looked like autumn. Sooner or later, those dead and dying forests will burn. When they do, I doubt trees will grow in their place.
The climate that made the forests possible will have moved.
There are thus at least two scenarios by which Australia’s forests might be permanently changing as we speak. One is that so much of the already-fragmented forests are burning that there won’t be enough left for effective recovery. Species could be extinguished through habitat loss, or through the loss of ecological partners, or simply by too many individuals, plant or animal, burning to death. Relict populations might be too small and too scattered to be self-sustaining. I don’t actually know, there is a lot of information I don’t have, but it seems at least possible that fires exacerbated by climate change are radically altering the ecological map of a country.
But the other scenario is that the alteration has already happened, that these forests were dead ecosystems walking even before the fires started, that the climate has changed and the fires are simply a form of belated adjustment to a new normal that began years ago.
Time for Hope?
As I said, I don’t know that the situation is as dire as it seems–it may not be. Real-life worst-case scenarios are rare.
Perhaps more to the point, even if the worst case is upon us, things are never so bad that they can’t get even worse, and that also means things are never so bad that we can’t avoid them getting worse.
Even if part of Australia’s forest is now doomed, it’s likely part of it still retains a climate conducive to forests. If conservationists scramble, and if they get the public and private help they need, it may be possible to create relicts that are large enough and interconnected enough to be self-sustaining.
And perhaps more to the point, if we all do something about climate change, maybe it won’t get much worse.
No situation is ever so bad that there is no reason to help.