Why Europe's wildfires are getting harder to stop

Wildfires in Europe have become increasingly difficult to contain due to a combination of factors. In France and Spain, authorities have blamed brush-clearing machines and heavy machinery sparks for igniting major blazes. However, scientists emphasize that these factors only explain the start of the wildfires, not their rapid growth.

European experts attribute the issue to three key ingredients: abundant vegetation, high levels of dryness in that vegetation, and favorable weather conditions. Climate change is exacerbating these conditions, making extreme weather more common and intense. A phenomenon called hydroclimatic whiplash, where ecosystems rapidly switch between wet and dry phases, has created an abundance of dry vegetation that quickly ignites.

In spring, warmer temperatures draw moisture from soil and plants, intensifying drought and turning fuel into kindling. This summer, fires broke out simultaneously in France, Spain, Greece, and Turkey due to the same pattern of heat and drought. Once a fire starts, containing it can take days or weeks, partly because many forests have been managed as monocultures of fast-growing trees.

These trees shed flammable needles that blanket the forest floor, making them highly susceptible to fast-moving fires. Furthermore, some trees, like pine and eucalyptus, have been planted extensively in recent decades as they are economically profitable. In Spain, over 3 million hectares of farmland and pasture have been replanted with these trees since the Franco dictatorship ended in 1975.

To reduce wildfire risk, experts stress the importance of tackling greenhouse gas emissions to mitigate climate change and intensifying weather extremes. Instead of monocultures, replacing them with mixed forests would provide better resilience to drought, windstorms, insect outbreaks, and fires. Planting broadleaf, deciduous trees like oak, beech, or maple, which store more moisture than conifers, can also help.

Trees with thick bark, fewer low-hanging branches, and higher moisture content tend to be more fire-resistant.