Summarised by Centrist
In 2020, new international regulations cut sulfur emissions from ships by 77%. Almost overnight, lightning over the world’s busiest shipping lanes near Singapore dropped by half.
Researcher Chris Wright and his colleagues analysed data from a global lightning detection network and found that ship exhaust plumes were directly linked to an increase in lightning activity—until the regulations took effect.
Ships burning high-sulfur fuel emit vast amounts of aerosol particles, which act as seeds for cloud formation. More particles mean more ice crystals and collisions within storm clouds, intensifying electrification and producing more lightning. The new study confirms that reducing sulfur in ship fuels meant fewer particles, fewer collisions, and ultimately, fewer lightning strikes.
This accidental experiment sheds light on a larger question: how much human emissions influence storms. Scientists have long debated whether pollution strengthens storms by fuelling more violent vertical motion or simply affects lightning generation.
The study found no other factors—such as El Niño or storm frequency changes—that could explain the sudden lightning drop, pointing to sulfur emissions as the key driver.
While cutting pollution is generally seen as a positive, the study raises questions about human intervention in atmospheric processes. Researchers continue to investigate whether regulating emissions could have unintended consequences for storm patterns and precipitation worldwide.
