Apropos the Aussie wildfires, here’s a fascinating paper from a few years back: Global trends in wildfire and its impacts: perceptions versus realities in a changing world.
Basically it says the world has been on fire for millions of years, long enough for species to evolve that cope with it or even rely on it. There’s a lot less burning going on than there used to be, even in recent modern times when rural burning was an important part of landscape management. Charcoal sediment analyses show that less burning is going on than anytime in the last 2000 years. Still, an astonishing 4% of the world’s land surface burns every year, around 30-40 million square km.
It is only recently that total fire suppression has been seen as a desirable thing, and media reporting reflects that. Australia had a 5% decrease in fires from 1996 to 2012, a period which include Black Saturday in Victoria, though the recent events will no doubt affect the stats. In the US, decades of fire suppression have increased the susceptibility of certain types of conifer forest to fires. But areas subject to traditional fire management show no increase. Compared to pre-European settlement, fires have decreased by half. Climate change may have increased the length of the fire season and the area burned in some regions but there is no significant trend.
Globally, fires are a miniscule threat to human life compared to other natural disasters. Studies attribute less than 4000 deaths to wildfires in the last century or so. In the same period there have been 2.5 million deaths from earthquakes and nearly 7 million from floods. Increased economic costs from fires reflect rising populations in the “wildland-urban interface”. This is not just from property loss but from increased spending on fire suppression. This may result in more deaths too – in some events two thirds of the lives lost are firefighters.