Once-in-a-century weather extremes that pose the highest danger of wildfires could occur every year in parts of the UK as the climate changes, scientists warn.
A study led by the University of Reading aimed to predict how the danger of blazes taking hold in the landscape would increase as a result of rising temperatures and less summer rainfall in the UK in the coming decades.
It found parts of eastern and southern England may face the highest threat level – known as “exceptional danger” – on up to several days a year on average by 2080, if the world continues to emit high levels of greenhouse gases, compared with those conditions occurring just once every 50-100 years today.
Exceptional danger days would become more commonplace across the UK by 2080, and days with a “very high” danger of wildfires could rise significantly, even in traditionally wetter parts of the country.
The rise in fire danger is predominantly due to hotter temperatures, less rainfall, lower humidity and stronger winds expected across the UK as a result of climate change, the research said.
The findings highlight the importance of taking the threat of wildfires – which can pose environmental, health and economic risks – seriously in the UK, as the problem is likely to grow, the researchers warned.
Professor Nigel Arnell, a climate scientist at the University of Reading who led the research, said: “Extremely hot and dry conditions that are perfect for large wildfires are currently rare in the UK, but climate change will make them more and more common.
“In future decades, wildfires could pose as much of a threat to the UK as they currently do in the south of France or parts of Australia.
“This increased fire danger will threaten wildlife and the environment, as well as lives and property, yet it is currently underestimated as a threat in many parts of the UK. ”
There are thousands of wildfires in the UK each year, which largely affect open arable, grassland, mountain or heath habitats rather than forests, but most are currently very small, covering less than a few acres or even just a few square metres.
Wildfires need a source of ignition, which can come from human activity and is hard to predict.
So the risk is measured by the likelihood a fire would develop after a spark – a danger which is affected by weather conditions, the scientists said.
Their study, published in the journal Environmental Research Letters, calculated what the fire danger might be in coming decades as climate change drives changes to those conditions, using the latest climate models for the UK.
They looked at both a future with significant action to cut carbon emissions and one in which pollution is high.
With high emissions, exceptional danger days, which are currently very rare across the UK, would become more commonplace across the UK, occurring up to nearly four days a year on average by 2080 in the worst-hit area, the east of England.
The study also found that, with high emissions, significant increases in days where weather conditions posed a very high danger of fire were seen all parts of the UK by 2080.
Southern and eastern England would be the worst affected, with the average number of very high danger days more than quadrupling to 111 days in the South East and 121 days in the east of England.
But the West Midlands would also see the number of danger days rise from 13 to 96 by 2080, and wetter areas could face soaring risk including Wales (up from five to 53), Northern Ireland (two to 20) and west Scotland (three to 16).
The study also showed that reducing greenhouse gas emissions to a level that would curb global warming to about 2C above pre-industrial levels “reduces very substantially” the increase in fire danger – although it does not eliminate it.