In July, a wildfire erupted in Müritz National Park in north-eastern Germany, presenting an unusual challenge for firefighting teams. Firefighters were joined by bomb disposal units due to the presence of Cold War-era munitions buried in the forest floor, which posed a risk of detonation if approached too closely.
Shortly after, another wildfire swept across 42,000 hectares in the Gironde region of Southwestern France. As it burned through fields near Le Porge village, the fire unearthed a hidden stockpile of World War II-era shells, with at least 75 recovered from the area.
During the fire, several shells exploded, and one projectile breached the wall of an evacuated house. Martial Zaninetti, the local mayor, expressed surprise, stating the municipality was unaware of the munitions’ presence.
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These incidents highlight a significant issue: Europe is riddled with unexploded ordinances from 20th-century conflicts, and the increasing intensity of wildfires is now bringing these dangers to the surface.
While buried munitions are inherently hazardous, they typically remain dormant unless disturbed. However, wildfires alter this dynamic by increasing heat and pressure, which can ignite or detonate explosives once they surpass a critical heat threshold. Aging ordnance is often more unstable due to corrosion, which makes casings and fuses more sensitive.
A brief fire burning through leaf litter and topsoil usually doesn’t cause explosions. In contrast, prolonged fires that burn for hours or days, or smolder underground in dry peat, can transfer enough heat to trigger buried explosives.
This scenario played out in 2025 during the Langdale Moor fire in North Yorkshire, UK, where deep peat fires ignited more than 20 buried World War II shells over six weeks.
Fires also reveal ordnance that might not otherwise be affected by heat. By burning off vegetation and topsoil, they expose buried shells and mines, leaving them on the surface, as seen with the 75 shells retrieved near Le Porge.
This phenomenon is not exclusive to wildfires. In Iraq, six munitions sites exploded during the summers of 2018 and 2019 due to extreme ambient temperatures exceeding 45 degrees Celsius, without any fire involvement. A similar situation was linked to a 2020 arms depot explosion in Jordan.
Europe’s buried munitions
Europe is littered with explosive remnants from two world wars and about four decades of Cold War military activity. Many of these munitions are located in areas now prone to wildfires, such as forests, moorlands, and heathlands once used for military purposes and then largely abandoned.
In north-eastern Germany, forests that are now nature reserves and UNESCO world heritage sites were once Soviet and East German training grounds during the Cold War. Germany’s ordnance-clearance service, the Munitionsbergungsdienst, tackles this contamination gradually due to its vast scale.
In Northern France and Belgium, farmers annually uncover World War I shells, known as the “iron harvest.” Parts of the “Zone Rouge” near Verdun remain uninhabitable a century after the 1918 Armistice.
Similarly, southwestern France, including the Gironde forests that burned in 2026, experienced intense fighting and stored munitions during World War II. In the UK, areas like the North York Moors were used for tank training during the Second World War, leaving buried ordnance in deep peat now susceptible to fire.
The character of fires in these areas has evolved. The devastating wildfires in Spain and France in 2026 exemplify Europe’s growing wildfire crisis, driven by consecutive heatwaves, low rainfall, and reduced soil moisture, creating extreme fire weather conditions.
Climate change is a significant factor in the increase of fire-prone conditions in the region. Extreme fire-prone summer days across southern Europe have doubled between 1981 and 2025, with projections indicating this trend will continue. As temperatures rise and rainfall patterns shift, the likelihood of extreme wildfires will persist.
Climate is not the sole factor contributing to Europe’s escalating wildfire activity. While North America and Europe are experiencing notable increases in fire frequency and intensity, global fire activity is decreasing. Changes in demographics and land management are altering the availability of fire fuel.
In Africa, for instance, the fragmentation of grasslands and changing agricultural practices have led to a decline in wildfires. In contrast, Europe faces the opposite trend. Rural abandonment has resulted in vegetation buildup, creating fuel loads that drive severe wildfires.
The combination of drier landscapes, extended fire seasons, and shifting land use is transforming Europe’s longstanding contamination issue into an ongoing operational threat.
This article was originally published on The Conversation. Read the original article.
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