I’ve seen four hypotheses advanced:
1. Natural cycles of drought: Throughout its history, Australia has had seasons of unusually high temperatures and numbers of fires.
2. Arson: So far, over 180 arrested for arson, including this guy.
3. Anti-human-management policies: Deadwood not removed, fire breaks allowed to grow over, and firefighters’ access to them blocked. [Update: Warnings from 2003 and 2009.]
4. Global warming: Modern civilization is causing higher temperatures, leading to more and worse fires.
None is exclusive, and the relative importance of each will be very hard to determine. Other hypotheses?
I am more interested into understanding why we hear so much about Australian fires (or, before that, the Amazon fires) and not the central African fires. Just South Sudan itself has a lot more fires on a much smaller territory if you look at global fire maps. The reporting on fires seems to be highly politicized.
The global warming argument about “more” fires is not very good because the number of fires worldwide is smaller than it was 20 years ago, with the number of fires going down by 20% until 2019 which has a noticeable bump but is still 10% lower than it used to be. But emotions are stronger than facts.
As to the fact that the fires are worse, there’s no doubt that number 3 plays a large role, as it has in California as well. Maintenance and controlled fires are important to reduce the risk from natural fires. But it’s probably a little of everything. A lot of people have been arrested for arson as you mention, but I don’t know how many of those tried to put a controlled fire to protect habitations.
In the Landes (the largest European forest I believe) there are measures to ensure that fires are taken out before they get too large. The forest is video monitored, there are a lot of dirt roads to get to where the fire begins (and I believe those roads also help prevent spread by compartmentalizing the forest), and there are a lot of water points dug up so that water can be used to stop the fires. The last large fire dates back 1949 and are probably why the system is as developed as it is now.
There’s no way around it, if you don’t maintain and prevent you will get worse fires.
Australia isn’t naturally very wet, so when natural forms of water storage are damaged then the land dries out. Look up the Australian Peter Andrews! And the work of John D. Liu – he is amazing. When we speculate about the political motives behind different hypotheses, or the statistics of weather patterns, we risk missing what’s right in front of us. I suggest going for a walk outside or watching a nature documentary instead.