Why fire remains a burning issue

“The only fire department on a university is the one that sends emergency vehicles when an alarm sounds.”

We need to know more about fire. Stephen Pyne, a professor at Arizona State University, points out that universities are dense with research into air, earth and water but that fire has escaped their attention. “The other ancient elements have academic disciplines devoted to their study,” he says. “The only fire department on a university is the one that sends emergency vehicles when an alarm sounds.”

Pyne’s quip is from the summary for a talk this month at the Royal Society in London, part of two days of discussion aimed at gathering the world’s experts to find out what we know and what we don’t. Climate change, urbanisation and the unprecedented pressure on agriculture to feed seven billion people have made the effects of fire a new priority.

Even the basics are letting us down. New Scientist reported last month that wildfire forecasts and simulations are rendering American firefighters ineffective against fires raging in the western United States. The simulations are failing to predict where the fires will spread in strong winds. Resources and personnel are being poorly assigned. In a year of violent fires, erroneous predictions are costly in all kinds of ways. Thanks to increased temperatures and extreme drought, the wildfire season now lasts longer than ever. Fire-setting experiments are still our best source of information about the likely consequences, yet the results are not reassuring.

A paper published in the September issue of BioScience, for example, has shown that the Amazon rainforest is not resilient to the frequent fires that are a likely consequence of increased global warming.

For the past ten years, a team of researchers has been setting fires in a 370-acre area of the Amazon to see how much of the rainforest bounces back when fires occur on different timescales. The natural three-year cycle is survivable but an annual fire-setting, which usually happens in areas hosting human activity, causes forested areas to degenerate permanently into grassland.

For all the appeal of narratives that involve wanton destruction by human beings, we might have been too hard on ourselves in some regions. William Bond of the University of Cape Town will argue at the Royal Society that we may even have got forest-saving policies wrong by being too quick to blame human-set fires. The received wisdom is that human beings burned African forests, creating savannah grasslands. But new analysis of the origins of African savannahs suggests that many existed long before mankind introduced fire into the landscape. That, to Bond, suggests some reforestation projects might be misguided.

Mostly, however, human practices are a big problem. Cristina Santín of Swansea University will present evidence that fire’s use in agriculture is having a huge impact on the quality of soils, causing vastly more erosion and even desertification than previously thought. Add in climate change and the picture becomes even more complex.

The other resource affected by fire is water. Forested areas are important providers of water for human settlements. When forests burn, the flow and quality of the water are altered. In particular, the concentration of minerals, heavy metals and nutrients can undergo significant changes – enough to threaten the water’s suitability for human use, Deborah Martin of the US Geological Survey will say at the meeting. If we want to make the earth sustainable, fire must become a hot topic.