Lightning-struck trees release as much carbon as the aviation industry

Lightning jolts the sky and the ground around eight million times daily, but the quiet deaths it causes in forests remain mostly out of sight. A recent study now estimates that about 320 million individual trees succumb to direct lightning damage every single year.

“We’re now able not only to estimate how many trees die from lightning strikes annually, but also to identify the regions most affected and assess the implications for global carbon storage and forest structure,” said Andreas Krause from the Technical University of Munich (TUM).

The team calculated that these silent strikes account for roughly 2 to 3 percent of all plant biomass lost annually, and end up causing the emission of up to 1.09 billion tons of carbon dioxide as the dead wood decays. 

Lightning kills trees silently

Forest pathologists often miss a lightning hit because the bark scars fade fast or never appear at all. Ground surveys in Central Panama were among the first to reveal how often a single bolt can kill multiple neighbors, especially among the biggest trunks.

The follow-up work at the same site showed lightning is responsible for about 40 percent of large-tree deaths, which is more than those caused by storms or insects in that forest. This finding hinted that global numbers could be far larger than the few local case studies suggested.

Direct counts alone could not scale to the whole planet, so the Munich group turned to modeling. They stitched satellite maps of lightning frequency with on-the-ground mortality rates and fed the mix into a dynamic global vegetation model that tracks how simulated trees grow and die.

Technicians now fly drones fitted with thermal sensors above tree-fall zones, watching for lingering heat that betrays an invisible bolt. These surveys confirm that many lightning deaths would go uncounted by ground crews alone.

Where and how lightning kills trees

The model, LPJ-GUESS, already simulates the impacts of fires, droughts, and logging. By adding a lightning module, the researchers let virtual strikes hit the tallest simulated stems first, mirroring the real preference of bolts for sky-piercing crowns.

The team ran the system with two independent lightning data sets, one from NASA satellites and another from a worldwide sensor network, to check robustness. The two runs agreed within about ten percent, landing on the headline figure of 320 million tree deaths in a year.

To test realism, they compared the virtual Panama plot with years of tagged trees and found the model killed roughly three trees per strike, close to field counts. That match gave the team confidence to push the simulation out to every half-degree grid square on Earth.

In the output maps, the hottest kill zones stretch across the Congo Basin, northern South America, and Indonesia, where warm, moist air fires up thunderstorms almost year-round. Temperate forests mattered less for now, but the model hints that their share could climb as the climate warms.

Tall trees die more often

The risk rises with height because taller trunks act like living lightning rods. Among trees wider than two feet (0.6 meters) across, lightning can account for one in 20 deaths worldwide, and nearly one in ten inside some African rainforests.

Losing a big canopy tree does more than thin the skyline. Each one packs about as much carbon as dozens of saplings, and shapes the light and humidity for everything growing beneath.

In tropical forests thick with lianas, the vines can even conduct electricity between neighboring trunks, which widens the kill radius. Such botanical wiring partly explains why a single discharge can fell clusters rather than lone stems.

Lightning and global carbon emissions

Forests hold around 870 billion tons of carbon in their wood and soil. Each year, living trees pull another 2.4 billion tons out of the atmosphere through photosynthesis.

Losing even two to three percent of that carbon stock every year is no minor loss – it matches the emissions released by burning live vegetation in wildfires.

The model calculates that lightning-killed wood releases as much carbon each year as the entire aviation industry. Most of that release happens slowly, as fungi and insects break down trunks that never burned.

Carbon accountants therefore need to track these non-fire disturbances, as well as considering the megafires that make headlines. Skipping them could underestimate natural greenhouse-gas sources as weather patterns shift.

Lightning does not always burn its victims, so the carbon flows into the atmosphere mostly as slow respiration, not smoke. That timeline complicates satellite assessments that rely on sudden fire scars.

Climate change may increase lightning

Warmer air holds more moisture and energy, and climate models suggest United States lightning strikes may jump about 12 percent for every degree of global warming.

Translated across the century, that projection means roughly 50 percent more flashes over mid-latitude lands.

Other research predicts fewer bolts in some tropical zones, showing the uncertainty that scientists still face. Even so, the new study underlines that any regional upswing could slice into forest carbon budgets that policymakers count on.

More strikes also raise the chance of wildfires, compounding the direct kills tallied here. Lightning already sparks most remote boreal fires, and an increase in strikes would lengthen the northern burning season.

Tracking trees with better tools

The authors note that their numbers omit hidden knock-on effects, such as insects invading scarred trunks or delayed deaths that follow partial damage.

Field crews armed with drones and lightning sensors could fill that data gap and sharpen future models.

“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,” said Krause. For now, the modeling exercise offers a first global baseline that forest managers can incorporate into planning. 

From carbon budgets to conservation goals, adding silent lightning mortality changes the arithmetic. Knowing how many trees fall from lightning makes it easier to keep the planet’s living green ledger in the black.

The study is published in the journal Global Change Biology.

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