Fewer Controlled Burns Means 6x More Wildfire Fuel and 7-Metre Flames: What Happens Next?
- Rob Beeson
- 2 days ago
- 8 min read
England's moorlands are at a critical juncture, facing an escalating threat from catastrophic wildfires driven by a confluence of restrictive land management policies and a warming climate.
Since 2021, regulations have curtailed traditional controlled burning by approximately 73%, leading to a rapid and dangerous accumulation of vegetation fuel. This article examines evidence from scientific modelling and recent wildfire events to compare two distinct future trajectories over the next 10–20 years:
Scenario A - Restricted Burning
Continuing the current "hands-off" approach will allow fuel loads to increase four- to six-fold, reaching 10–15+ tonnes per hectare. This trajectory virtually guarantees larger, more intense wildfires with flame lengths exceeding 7 metres - far beyond the capacity of firefighting services to control.
The consequences include massive carbon releases from burning peat, irreversible ecosystem damage, and significant risks to public safety, infrastructure, and rural economies. The prevailing expert consensus is that under this scenario, a catastrophic moorland megafire is "not if, but when."
Scenario B - Active Fuel Management
Reinstating a proactive strategy of rotational controlled burning (treating ~10% of moorland annually) would maintain a mosaic of younger vegetation and low fuel loads. This approach results in smaller, less intense wildfires with flame lengths typically in the 1–2 metre range, which are manageable for ground crews.
This scenario significantly reduces the risk of deep peat ignition, minimizes carbon emissions, protects biodiversity, and enhances the overall resilience of the landscape to climate change.
The evidence strongly indicates that the current policy path is unsustainable and is actively increasing the likelihood of disaster. A strategic shift toward active fuel management offers a proven, cost-effective, and ecologically sound method to mitigate this growing threat, safeguarding both the environment and communities.
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The Policy Crossroads: Restricted Burning vs. Active Management
The future of wildfire risk on English moorlands is directly tied to policy decisions governing vegetation management. A dramatic shift in regulations since 2021 has moved away from historical practices, creating two sharply contrasting approaches.
Heather and Grass Burning Regulations
In 2025, England implemented regulations that effectively banned routine heather burning on peat soils deeper than 30 cm within protected areas without a specific license. In practice, licenses for wildfire prevention have been difficult to obtain, leading to a near-cessation of controlled burns on deep peat since 2021, when regulations were introduced restricting burning on peat deeper than 40cm.
This policy reflects a trend toward non-intervention on peat moors, driven by concerns over habitat degradation and carbon release.
Impact on Management: A remote-sensing study found that the area subject to managed burning in England dropped by 73% in 2021/22 compared to the average of the four preceding years.
Alternatives: While mechanical cutting and grazing are promoted as alternatives, cutting is limited by terrain and can leave flammable debris, while upland grazing has decreased due to agricultural policy changes.
Historical Practice: Rotational Mosaic Burning
Traditionally, moorlands were managed on a rotational burning cycle of 8-15 years for any given patch. Land managers would conduct cool, controlled burns (muirburn) on approximately 10% of the moorland each winter.
Objective: The goal was to create a patchwork or "mosaic" of different-aged heather. This provided nutritious young browse for grouse and sheep while leaving older stands for cover.
Method: Burns were small-scale and conducted under cool, damp conditions to ensure only surface vegetation was consumed, leaving the underlying peat and moss layers intact and unharmed.
Outcome: This practice limited the build-up of old, woody vegetation and created natural fire breaks, preventing the spread of any potential wildfires.
The Science of Moorland Fire: Fuel, Climate, and Behaviour
Wildfire behaviour is governed by fuel, weather, and topography. The current policy debate centres on the fuel component, which is directly altered by management choices.
Fuel Accumulation Dynamics
The cessation of managed burning leads to a rapid increase in the amount and continuity of flammable vegetation.
Heather Growth: After 15–20 years without management, heather stands become tall (60–90 cm), woody, and filled with dead material. Total fuel loads can increase four- to six-fold compared to recently burned areas.
Fuel Load Increase: Areas that once carried 2–4 tonnes/ha of fine fuel can accumulate 10–15+ tonnes/ha of combustible material after two decades of exclusion from fire.
Other Vegetation: Unmanaged purple moor-grass (Molinia) develops a deep, flammable litter layer, while scrub and bracken encroach, adding to the overall fuel load and creating "ladder fuels."
The Link Between Fuel Load and Fire Intensity
A core principle of fire science is that higher fuel loads produce more intense and dangerous fires.
Fireline Intensity: Unmanaged fuel loads can increase fireline intensity from a manageable level of under 1 MW/m to a catastrophic level of over 10 MW/m.
Flame Length: This increase in intensity translates directly to taller flames. A fire that would produce 1-2 metre flames in a managed landscape can generate flames of 6-8 metres in an unmanaged one.
Suppression Thresholds: Firefighters can safely engage fires with flame lengths up to ~2 meters. Beyond 3.4 metr0es, direct ground attack becomes impossible, and the fire is effectively uncontrollable by conventional means.
Peat Ignition: High-intensity surface fires generate enough heat to dry out and ignite the underlying peat, leading to deep, smouldering fires that can last for weeks and release vast amounts of carbon.
Climate Change as a Threat Multiplier
Projected climate change will significantly worsen fire weather conditions, amplifying the risk created by high fuel loads.
Hotter, Drier Summers: By mid-century, extreme heatwaves will become more frequent, and summer rainfall is projected to decrease, leading to more common and severe droughts.
Longer Fire Season: The traditional wildfire season (March-September) is expected to start earlier and end later, increasing the overall period of risk and shrinking the safe window for conducting controlled burns.
Increased Danger Days: Under high-emissions scenarios, the number of days with "exceptional" wildfire danger could quadruple by 2080. Even by 2050, the frequency of "very high" fire danger days is expected to double. This means the conditions required for catastrophic fires will occur far more regularly.
Modelling and Real-World Evidence
Recent risk assessments and major wildfire events provide clear, quantitative evidence of the growing threat.
The Peak District Wildfire Risk Assessment (2022)
This comprehensive study modelled potential wildfire behaviour under current fuel and extreme weather conditions, reaching several stark conclusions:
Inevitable Catastrophe: The report concluded that without intervention, a massive, uncontrollable wildfire is "not if, but when."
Extreme Fire Behaviour: Modelling predicted potential flame lengths up to 7.6 metres and spread rates of 2.4 km/h in long-unburnt vegetation.
Exceeding Capabilities: Large areas of the Park were identified where potential fire behaviour would exceed the 3.4-metre flame length threshold, meaning local Fire and Rescue Services would have "little to no chance" of controlling a blaze.
"Fire Highways": The assessment mapped corridors of continuous fuel that could facilitate rapid, large-scale fire spread.
Case Studies from Recent Wildfires
Real-world incidents validate the models and demonstrate the consequences of high fuel loads.
Saddleworth Moor (2018): This fire burned for over two weeks in an area of long-unburnt heath on deep peat. It released an estimated 0.5 million tonnes of CO₂ and cost an estimated £8.76 million.
North York Moors (2025): A fire started by a campfire scorched approximately 5,000 acres, spreading rapidly through areas dominated by mature (17–25 year old) heather where burning had been restricted.
Marsden Moor (2019, 2021): Intense fires required firefighters to fall back and rely on fire breaks created by farmers and gamekeepers to halt their spread, demonstrating the limits of direct attack in heavy fuels.
Two Futures: A 10-20 Year Outlook
The choice of management policy will lead to fundamentally different outcomes for England's moorlands over the next two decades.
Feature | Scenario A: Continued Restricted Burning | Scenario B: Active Fuel Management |
Fuel Load & Structure | Widespread, continuous old vegetation. Average fuel loads of 10–15+ t/ha. | A managed mosaic of different age classes. Average fuel loads of 2–4 t/ha. |
Typical Fire Behavior | Intense fires with flame lengths of 5–8 metres in extreme weather. High potential for deep peat ignition. | Less intense fires with flame lengths of 1–2 metres. Peat ignition is rare. |
Fire Size & Spread | Fires can become uncontrollable, spreading rapidly across thousands of hectares. High probability of "megafire" events. | Fires are compartmentalized by the mosaic, typically limited to tens of hectares and more easily contained. |
Firefighter & Public Safety | High risk. Fires frequently exceed suppression thresholds, endangering crews. Smoke pollution affects communities. | Lower risk. Fires remain within manageable limits, enhancing firefighter safety. Smoke and evacuation events are far less likely. |
Carbon & Peat Impact | Catastrophic. Deep-burning fires release massive amounts of stored peat carbon, turning carbon sinks into sources. | Protective. Small, cool burns protect peat stores from wildfire, resulting in far lower net carbon emissions over time. |
Economic Cost | Extremely high. Costs include suppression, infrastructure damage, and lost revenue. Deep-peat fires can exceed £20,000/ha. | Low. Proactive management is a low-cost investment that prevents multi-million-pound disaster response and damage costs. |
Overall Outcome | A landscape prone to recurrent, devastating wildfires that overwhelm response capabilities. | A resilient landscape where fire is a manageable element, not a catastrophic threat. |
Strategic Implications and High-Risk Zones
An effective wildfire strategy must target the areas of greatest risk and consider the wide-ranging consequences of inaction.
Identifying Priority Areas for Mitigation
Fuel management under an active strategy should be prioritized in zones where the consequences of a wildfire would be most severe:
Deep Peat Plateaus: To protect vast carbon stores and sensitive habitats.
Slopes Above Infrastructure: To safeguard roads, railways, and power lines from damage and disruption.
The Wildland-Urban Interface (WUI): To create defensible space and protect communities bordering moorlands from fire and smoke.
Historical Fire Hotspots: To treat areas with a demonstrated vulnerability to extreme fire behaviour.
"Fire Highways": To break up long, continuous stretches of fuel that enable rapid fire spread.
Environmental and Economic Consequences
The trajectory of restricted burning has profound negative implications:
Carbon Emissions: A single large wildfire can negate years of carbon sequestration. In severe fires, 98% of carbon loss can come from the peat layer itself.
Water Quality: Ash and sediment from burned moorlands pollute reservoirs, increasing water treatment costs and downstream flood risk.
Economic Costs: The UK has already incurred costs exceeding £460 million from wildfires in 2025 alone. These costs, covering suppression, damages, and lost rural income (tourism, agriculture, shooting), will climb under the current trajectory. In contrast, proactive management is a fraction of the cost of disaster response.
Key Takeaways
The evidence overwhelmingly demonstrates that the current policy of restricted burning is setting the stage for catastrophic moorland wildfires. By allowing fuels to accumulate to dangerous levels, this approach increases the probability of fires that are larger, more intense, and more destructive than anything manageable by current firefighting capabilities.
The alternative - a return to active fuel management through controlled burning - offers a proven path to mitigate this risk, creating a more resilient landscape that is safer for communities and healthier for the environment. The decision to act now can avert predictable disasters, whereas continued inaction makes them an inevitability.
Key Messages for Decision-Makers
Heavy Fuel = Severe Wildfire: Moorland fuel loads have surged due to restricted burning, increasing wildfire intensity and making some fires virtually uncontrollable for ground crews. Reducing fuel through management is essential to tame fire behaviour.
Current Trajectory is Unsustainable: Continuing the hands-off approach makes more large, high-intensity wildfires a near certainty in the next 10–20 years. It’s “not if, but when” for a catastrophic moorland fire under current policies.
Active Management Prevents Disaster: A proactive burning program can cut fuel loads by 4–6×, yielding shorter flames, slower spread, and fires that firefighters can control. It is the single most effective tool for reducing wildfire risk.
Small Burns vs. Big Fires on Carbon: Frequent cool burns release minimal carbon and protect peat, whereas rare mega-fires release orders of magnitude more CO₂ and destroy ancient peat stores. Active management is vastly preferable for carbon and habitat protection.
Climate Change Amplifies Risk: Hotter, drier summers will make extreme fire-weather days far more frequent. Fuel management is the best defense to keep wildfires within manageable bounds in a warming climate.
Protecting Communities and Infrastructure: Strategic fuel breaks created through active management are critical to prevent wildfires from threatening villages, roads, and utilities.
Economic Sense: Investing in preventative burning is far cheaper than paying for wildfire damage and suppression, which already costs millions. Proactive management safeguards rural economies from wildfire disruptions.
Urgency of Action: A window of opportunity exists now to alter this dangerous trajectory before accumulated fuels and climate pressures peak. Decisions made in the next few years will determine the future of England's moorlands.
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