Scientists in Scotland have developed a new method to understand the heat and intensity of fires that burned out millions of years ago, which could unlock our understanding of wildfires during past and present periods of climate change.
Scientists in Scotland have developed a new method to understand the heat and intensity of fires that burned out millions of years ago, which could unlock our understanding of wildfires during past and present periods of climate change.
Developed by geoscientists at the university of Aberdeen – Dr Thomas Theurer, Dr Dmitri Mauquoy, Professor. David Muirhead, Dr Clemens von Scheffer, and Daniel Coathup – and fire engineers at the university of Edinburgh – Professor Rory Hadden, Dr Zakary Campbell-Lochrie, and Sergio Vargas Córdoba – the new technique to analyse charcoal can be applied to understand the behaviour of any wildfire, from the present day all the way back to the first evidence of wildfire 420 million years ago.
They published their findings in the Nature journal Scientific Reports.
The increase in wildfire activity is a major global concern, especially for vulnerable wetland ecosystems that play a key role in storing carbon and fighting climate change.
Last month’s devastating wildfires in California, which destroyed or damaged more than 18,000 homes and structures, brought to global attention how the size of the areas affected by wildfires is growing, individual fires have increased in intensity and the fire season has extended.
The recently published Forest Fires 2023 report, says this shows ‘the undeniable effects of climate change’.
In addition to the devastation caused by fires which spread rapidly across forests and moorlands, so called ‘zombie fires’ also burn in peatland, smouldering deep in the soil, and can release 100 times the carbon that a wildfire does
Wildfires have occurred throughout geological history, including during periods of extreme climate change.
In creating a method to measure historical events, scientists applied state-of-the art analyses using a laser, called Raman spectroscopy, to charcoals created during experiments at the University of Edinburgh Rushbrook Fire Laboratory simulating wildfire.
It is the first calculation of wildfire energy release measured from charcoal chemistry, the team say, that can be applied to complex, natural fuel mixes and wildfire reconstructions of any age.
Dr Thomas Theurer, a research Fellow at the University of Aberdeen, said: “As geoscientists, we can study simultaneous changes in ancient plant communities, climate, and fire that are often preserved in rock, and begin to understand the drivers of intense fire activity in the past, and how this modifies ecosystems.
“As charcoal can persist within rocks for hundreds of millions of years, this method can be applied to understand the behaviour of any wildfire, from the present day all the way back to the first evidence of wildfire 420 million years ago.”
Dr Dmitri Mauquoy, Senior Lecturer in Geosciences at the University of Aberdeen added: “Current methods to estimate ancient fire temperatures, called ‘geothermometry’, study specific changes in charcoal chemistry that result from the temperatures experienced during a wildfire event. However, energy release and transfer in wildfires is a complex process that cannot be understood through temperature measurements alone. Therefore, these methods may not be as accurate or useful in understanding ancient fire behaviour as previously thought.
“The method we have developed allows us to quantify the energy release from wildfires using charcoal remains – the first and only method of its kind that is non-destructive and universal to complex, natural mixes of vegetation as fuel.”
Understanding modern wildfire activity and how it may change with escalating climate change is complicated by the modification of environments by humans throughout history – such as forestry, agriculture, and fire suppression.
“By applying this new method, we are able to get insights into how past fire activity has changed with climate change, independent of human interference, in a way that allows comparison to modern wildfire activity,” said Professor Rory Hadden, Personal Chair of Fire Science at the University of Edinburgh.
“This allows us insights we can use to assess and contextualise predictions of future fire activity, and how they may impact global ecosystems and populations.
“As charcoal is a commonplace by-product of fire, it is exciting to think how this method might be applied to other areas of study, such as archaeology, forensic fire investigations, and fire safety science more broadly.”