Wildfire Science Keeps Pointing Back to Fuel on the Ground

Photo by Scott Wicking

Quick summary

• A Guardian report says UK wildfire risk depends on fuel as well as weather.

• One study found the UK fire season grew from 1-4 months (2011-16) to 6-9 months (2017-21).

• Severe summer fires on moorland have burned up to 20 cm into the peat in places.

• Fuel is the part of wildfire risk that land managers can reduce all year round.

A recent Guardian article looks at how UK specialists are trying to predict and prevent wildfires.

It reports summer fires burning into moorland peat. Much of it is also about fuel - the vegetation a fire burns.

Nobody knows for sure what starts most wildfires

England has roughly 30,000 vegetation fire ignitions a year, according to the article. Most fizzle out quickly, but understanding their patterns could stop more becoming major incidents.

"Preparedness and prevention is where you win the wildfire."

Rob Gazzard, the Forestry Commission's wildfire contingency planning adviser

The article reports growing pressure:

• summer 2026 was the UK's hottest on record, with extreme and persistent drought

• 2025 set a record for land burned by wildfires

• by mid-August 2026, firefighters in England and Wales had attended more wildfires than in the whole of 2025

A 2023 Forestry Commission report said fire causes are generally judged by staff with limited or no specialist training. It also said research by wildfire scientists found cigarettes an extremely unlikely cause.

Andy Elliott, founder of WildfireTaC, says that beyond people, the UK doesn't know what causes its wildfires. The article adds that lightning and birds striking power cables could start more fires when vegetation is very dry.

For the MA, the lesson is that some fires will start whatever is done to prevent them. How far they spread depends partly on what they find to burn.

Fuel decides how fiercely a fire burns

Until recently, wildfire risk forecasting mostly looked at weather, the article reports, but fuel matters too.

Researchers including Sarah Baker of the University of Exeter have measured how readily British vegetation ignites in different seasons. That work fed into FireInSite, a system firefighters increasingly use. It predicts how fast a fire will spread and how large its flames could become. It uses the type and amount of vegetation, the season and the weather.

Elliott says that when FireInSite predicts flame lengths of six to eight metres, helicopters are needed.

"Attacking it with a fire beater is just not going to work..."

Andy Elliott, the UK's only serving fire officer trained in specialist wildfire origin

Flame size depends on how much there is to burn. Land managers can change that before a fire ever starts.

Summer fires are burning deeper into peat

Most UK wildfires have traditionally happened in late winter and spring. Dead grass, bracken and other vegetation left over from winter fed them. In summer, green growth usually acts as a natural barrier, but prolonged drought can dry it out.

A study led by Baker found the UK wildfire season lengthened. It went from between one and four months in 2011-16 to between six and nine months in 2017-21.

Prof Stefan Doerr of Swansea University says summer fires are much harder to put out. Baker is seeing many more summer moorland fires that can burn down into the peat.

"We're getting measurements of up to 20 centimetres in some areas."

Sarah Baker, assistant director of the Wildfire Lab at the University of Exeter

The article says this could hinder the regeneration of burnt moorland and release extra carbon as the peat burns.

Small gaps in vegetation may decide where a fire goes

FireInSite shows how a fire will burn. Predicting where it will go needs fire-spread models.

Prof Tom Smith of the London School of Economics is working to adapt these for UK conditions.

Researchers could simulate thousands of fires to find the "pinch points" that fire repeatedly passes through. The article says this could help land managers target and test changes to vegetation in strategic places.

"In the UK, a lot can happen in 30 metres."

Prof Tom Smith, London School of Economics

Smith says the difference between a 1-metre and 2-metre-wide path could decide whether flames cross from one patch to another.

How controlled burning, cutting and grazing reduce fuel

The MA's position is that wildfire risk depends on weather, ignition and fuel. Of the three, fuel is the one land managers can change.

Each method lowers the fuel load, meaning the amount of dry, burnable vegetation on the ground.

• Controlled burning removes older, taller heather in small patches and leaves younger regrowth behind.

• Cutting does a similar job where burning is not suitable.

• Grazing stops vegetation building up.

Together they break continuous stretches of vegetation into a patchwork. Less fuel means lower flames and a better chance that crews can tackle a fire on foot.

Managed ground also carries less of the dead winter material the article links to spring fires. A fire that burns less intensely is less likely to damage the peat below.

The MA sees fuel management and peatland rewetting as working together.

Why this matters

Practical, year-round management of moorland fuel gives crews smaller fires to fight and helps keep moorland peat intact.