Why Europe's wildfires are getting harder to stop

Wildfires almost always need a spark to ignite, whether it's lightning, arson, or a car's hot exhaust pipe touching dry vegetation.

In France's historic summer wildfires, authorities blamed a brush-clearing machine being operated around a high-voltage power line. Spanish investigators concluded that sparks from heavy machinery were behind major blazes there.

But scientists say those findings only explain how Europe's historic wildfires began, not why they grew into the megafires that have devastated the continent this summer.

Across Europe, a combination of human-caused climate change, insufficient planning and forests planted in ways that allow flames to spread quickly are fueling fires, say experts.

"It's not that wildfires are magic and just start. You have to have the right climatic conditions," said Silvia Abruscato, coordinator of FoRISK, a pan-European forest risk management hub. Has Europe lost control of its wildfires?To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video