A new study finds that lightning kills some 320 million trees around the world each year, more than was previously thought. And that figure could rise in the decades ahead as increasingly hot and humid weather fuels more lightning, particularly in forested parts of the Far North.
To study the impact of lightning, scientists had, in the past, tallied the number of trees that appear to have been struck. But it’s not always obvious which trees were struck. Some dead trees are so decomposed that they bear no obvious signs of a strike, while others may succumb only months later.
The new study uses on-the-ground observations and global lightning data to model the number of trees lost globally to strikes. “We’re now able not only to estimate how many trees die from lightning strikes annually, but also to identify the regions most affected,” said lead author Andreas Krause, of the Technical University of Munich.
Scientists looked only at the number of trees lost to lightning strikes and did not tally the trees that perish in resulting wildfires. Still, they found that trees killed directly by strikes unleash around a billion tons of carbon dioxide yearly, roughly as much as is emitted by Japan. The findings were published in Global Change Biology.
The study’s authors say that while lightning is currently deadliest for trees in the tropics, particularly in Africa, it could pose a growing threat at higher latitudes as the planet warms. Said Krause, “Most climate models project an increase in lightning frequency in the coming decades, so it’s worth paying closer attention to this largely overlooked disturbance.”
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