Global warming and land use change to drive more extreme wildfires

According to a new UN report, extreme wildfires will become more frequent and increase by about 50% by the end of this century.

The report notes that there is an increased risk in the Arctic and other regions not previously affected by fires.

The scientists define extreme fires as extraordinary large fires that occur about every hundred years.

Researchers say rising temperatures and changes in how we use land will drive the rise.

The new study calls for a radical shift in financial resources from firefighting to prevention.

The United Nations Environment Program (UNEP) scientists say that large fires that burn for weeks are already burning hotter and longer in many parts of the world that have always had wildfires.

But they are now beginning to flare up in remote northern areas, in drying peatlands and on thawing permafrost.

According to this latest study, there will be a global increase in extreme fires of up to 14% by 2030 compared to the number recorded in 2010-2020. The increase could reach 30% by 2050 and 50% by the end of the century.

“The analysis was based on the definition of a catastrophic fire that occurs once every 100 years, so it’s a very rare fire event,” said Dr. Andrew Sullivan of the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Canberra. Australia.

“The result was that the potential for this type of fire would increase by a factor of 1.3 to 1.5, based on a global analysis of fire frequency.”

The results were similar in a low or high carbon emissions scenario.

The study defines extreme firebrands as exceptional or unusual fires, but this definition can vary significantly by location.

“If you imagine a peat fire in the Arctic, it’s spreading at centimeters per hour. It’s not necessarily a raging inferno, but it’s unusual and spreading over huge areas because there’s nobody who can do anything about it,” said Dr. Sullivan.

“A fire like this on the moors is an extreme fire, but it’s not what you would imagine an extreme fire to be if you live in California.”

And although the study only forecasts extreme events, the authors believe that fewer wildfires will also increase as land use changes and population increases. This could have a significant impact on climate change as the additional burning increases the amount of carbon emitted into the atmosphere.

But the change in frequency depends on a number of local factors. The world is likely to see more fires in arctic regions because climate change is having such a major impact on the region.

However, Africa, which currently hosts about two-thirds of the world’s wildfires, is likely to experience fewer fires in the coming decades as a growing population clears more forested land for farmland.

“In Africa, the number of fires is decreasing due to changing land use and agricultural intensification,” said Dr. Glynis Humphrey from the University of Cape Town.

“Our percentage of area burned is actually decreasing, and our fires are getting smaller due to the reduction in fuel loads.”

The authors call on governments to change their spending model for major fires.

Currently, the study states that planning and prevention receive less than 1% of the funds, while firefighting consumes more than half of the available budget.

Many governments have good intentions to spend more on planning and prevention – but the reality on the ground is different.

“We need to invest more in fire prevention, in comprehensive management, also so that fires can fulfill their ecological role,” said Prof Paulo Fernandes of the Universidade de Trás-os-Montes e Alto Douro in Portugal, one of the report’s authors.

“But then, when things heat up, their reaction will be to deviate from the policy that should apply. There’s a lot of talk in places like California, but when it comes to action, they always put the money in the same place, fighting fires.”

Follow Matthias on Twitter @mattmcgrathbbc.