Europe's wildfires are unearthing a deadly legacy: unexploded wartime bombs

Wildfires sweeping across Europe this summer have brought a hidden threat to the surface: unexploded bombs and mines from the World Wars. The intense heat has caused some of these buried weapons to detonate, with blasts reported in France, Belgium, Germany, and the Netherlands.

In the Netherlands, a bomb-disposal unit was called to a forest near a 1944 battlefield in Limburg province as flames approached. The incidents underscore how a changing climate is disturbing a legacy that had long remained dormant.

"Climate change is now doing the work of unburying and reactivating what was previously stable," said Sarah Njeri, a peace and conflict scholar at London's School of Oriental and African Studies. She noted that steady temperatures and predictable rainfall once kept most buried weapons inert.

This year's fire season was fueled by heavy January rains that spurred vegetation growth, which later became dry kindling under summer heat, drought, and strong winds, according to a recent study by the World Weather Attribution group.

In France, a large wildfire near Bordeaux uncovered a cache of what is believed to be WWII-era ammunition. In Belgium's Liege province, Governor Hervé Jamar reported "a few sporadic detonations" in a fire zone, though no fire crews were endangered. Local media showed a firefighter holding a rusted bomb.

The High Fens, a peat-bog forest straddling the Belgian-German border, is a particular concern. The area was a brutal battlefield during the Battle of the Bulge and other engagements, including the 88-day Battle of Hurtgen Forest, which claimed tens of thousands of lives. Local historian Bernard Collard, who runs a museum near the border, said munitions killed six civilians in the four years after Germany's 1945 surrender. "When you go into a forest like this, you are not sure where the explosives are," he said.

Collard, authorized to scan former battlefields with a metal detector, has found mortar shells, machine guns, and even a human skeleton. He frequently works with Belgium's demining squad. "It's part of our history. We live with it," he said.

Heat can trigger the explosives, making them more dangerous during wildfires, said Jonas Tepe, a spokesperson for North Rhine-Westphalia in Germany. Belgium's Ministry of Defense receives weekly requests to disarm explosives, though it does not consider the region a "hot spot" compared to other areas. Nationwide, Belgium's bomb disposal service handles over 3,000 calls annually, disposing of 200 to 250 tons of leftover munitions.

Drought has also exposed ordnance by lowering water levels. In Slovakia, the Danube River revealed two naval mines, which police removed for a controlled demolition. In Hungary, a WWII bomb surfaced at the base of Budapest's Margaret Bridge, forcing its closure. German authorities found another bomb as the Rhine shrank.

"The legacy of war keeps creeping up," said Christina Greene, a researcher at the University of Arizona. "It's reliving the legacies of war and conflict in a way that we haven't had to deal with in a while in certain places."