Lightning sparks wildfires, causes pollution and destroys some of the planet’s most important trees. Climate change could see its incidence – and impact – increase
24 June 2020
WEAVING through the sweaty tangles of a Panamanian forest, Steve Yanoviak is hunting a killer. Its prey isn’t the monkeys, bats or multicoloured birds that cram the branches, but the foundations of the forest itself – its trees. Each day, this killer strikes thousands of times around the world, but leaves no evidence behind. “Tropical trees die standing. They bear no scars,” says Yanoviak.
Catching it in the act takes monumental effort. That’s because the likely culprit isn’t a living organism, but instead a familiar force of nature: lightning.
Yanoviak, an ecologist at the University of Louisville, Kentucky, is just one of many researchers around the globe confronting the profound, underappreciated effects that lightning has on the natural world. It ignites wildfires that reset ecosystems. It can boost greenhouse gases, and unleashes other pollutants in an instant. And in the tropics, it is the grim reaper that singles out the most magnificent of ancient forest trees for destruction.
What’s more, lightning is probably on the increase, and that’s because of us. Climate change seems to be driving up the frequency of strikes, while population growth and changes in land use are exacerbating their effects. The toll on both the human and natural spheres has sparked a new urgency in getting to grips with this everyday phenomenon.
It all begins harmlessly enough, with moisture-laden hot air that rises from the warm surface of Earth. As it cools, water vapour condenses around microscopic particles – things like dust, pollen, sea salt and smoke – to form droplets and clouds. As they rise and cool further, these droplets turn to …