Today it's the Amazon's forests. Are our forests safe?
The images of fire in the Amazon rainforest are shocking everyone. I really hope that it is just the result of misguided policies by the new Brazilian government because, if it is, those policies can be reversed.
There is another, and much more worrying, possibility - it may also be the consequence of climate change.
As NASA - whose satellites keep watch on the Amazon - puts it: "Both natural and man-made fires often coincide with the [Amazon's] dry season from July through October."
However, wildfire reports are coming with increasing frequency from across the globe. In the last year alone fires in the Arctic, Australia, Malaysia, California, Brazil and the Canary Islands have been big news.
Partly it’s because forest fires have become newsworthy and are getting reported more often, but one of the predictions of climate science is that a warmer world is also one of more extreme weather. We can expect stronger winds, heavier rainfall, rougher seas and longer droughts and those droughts lead to wildfires.
The scientific evidence that global warming is causing at least some of the increase in wildfires is strong. It’s been an area of intense scientific research since the early 1990s.
One paper by US Forest Service employee Matt Jolly and co-workers looked at the trends in forest fires from 1979 until 2013 (https://www.nature.com/articles/ncomms8537). Their conclusion was that the area of the world’s forests that was vulnerable to wildfires had doubled.
It’s not just the destruction of biodiversity that’s the concern here. The global output of carbon dioxide from forest and savannah fires is already about 25 per cent of the amount from burning of fossil fuels (https://www.atmos-chem-phys.net/6/3423/2006/).
This leads to the possibility of a powerful positive feedback - more warming gives more fires which gives more carbon dioxide which gives more warming. If this cycle takes off then it will no longer matter whether we cut back our own emissions, we’ll be stuck with extreme global warming.
Could such a cycle of increasing warmth and increasing forest fires even affect our own local forests? The short answer is yes. My colleague at Royal Holloway, Professor Andrew Scott, has spent his career looking at the evidence for fires in the distant past to try and understand the links between climate, fire and atmospheric composition.
He’s sufficiently concerned about the increased risk of wildfires in the UK today to have been lobbying parliamentary committees to take it seriously.
The data seems to back him up, the graph shows the number of forest fires in the UK as determined by the European Forest Fire Information System. As you can see, 2019 is already the worst year on record and there has been a dramatic increase since 2014.
There is a lot of fluctuation from year to year, as shown by the relatively high number of fires in 2011 and 2013, but nevertheless the trend is worrying. Future wildfires in Britain's forests cannot be ruled out.
25 August 2019