Around the world, 60 lightning flashes hit every second — each one capable of releasing up to seven gigajoules of energy and heating surrounding air to 30,000°C. This constant electrical discharge regulates Earth's electrical field, drives the nitrogen cycle, helps break down methane, produces ozone, and ignites the fire cycles that shape forests and grasslands. Lightning is not weather decoration. It is planetary infrastructure. As the atmosphere warms, the intuitive expectation is more thunderstorms and more lightning. A warmer atmosphere holds more water vapour, providing more energy for the deep convection inside thunderclouds that generates electrical charge. But a recent review of lightning studies — currently under peer review — finds projections spanning an 11% decrease to a 44% increase in lightning per degree of global warming, with a mean increase of 7.5% per degree. The range is the signal: the models disagree fundamentally about what warming does to lightning in tropical regions, even as they converge on increases at high latitudes. The consequences of getting this wrong are already visible. In July 2026, more than 48,000 lightning strikes ignited massive wildfires across Canada and the north-west United States, destroying homes and blanketing cities in smoke. During a British heatwave last summer, nearly 30,000 strikes hit south-east England in a single day. Globally, roughly 250,000 people are struck by lightning annually, killing about 24,000. In Australia alone, five to 10 die each year with about 100 injured. The modelling challenge is structural. Lightning is generated when colliding ice crystals and graupel inside storm clouds separate charge until an electrical field becomes intense enough for discharge — but the fields produced are only about a tenth as strong as needed to spark on their own. What actually triggers the flash remains contested: recent research points to cosmic rays providing the catalyst, while other studies implicate runaway buildup of ionised-air streamers. Until satellite measurement arrived in the 1990s, data relied on ground-based observations, leaving historical baselines thin. Andrew Dowdy at the University of Melbourne has tracked thunderstorm frequency back to 1979 by combining cyclone and front records, revealing increased activity along eastern continental coasts and a poleward shift in southern-hemisphere cyclone activity — but also declines in tropical northern Australia. The wildfire accelerant is dry lightning — strikes that occur without accompanying rain. Australia's Emergency Leaders for Climate Change recently warned that fires started by dry lightning are increasing. This matters because dry-lightning fires ignite remote, inaccessible terrain during already-extreme heat, compounding suppression difficulty. The combination of more lightning at higher latitudes, drier fuels, and longer fire seasons creates a feedback loop: lightning ignites fires that release carbon that further warms the atmosphere. Human activity is already altering lightning distribution in unexpected ways. Storms over ocean shipping lanes are enhanced by aerosol particles in ship exhaust, which change cloud formation processes. More than 80% of lightning occurs over land, concentrated in central Africa, South America, and the Himalayas, but ocean storms can achieve far higher flash densities — one 1998 Indian Ocean storm produced eight flashes per second, making the sky appear permanently lit. Venezuela's Catatumbo region generates thunderstorms on 140 to 160 nights a year. The policy gap is clear. Lightning research remains a niche within atmospheric science, yet lightning drives wildfire ignition patterns, shapes ecosystems, regulates atmospheric chemistry, and kills tens of thousands annually. The 11%-to-44% projection spread per degree of warming means infrastructure planning, fire management, and insurance modelling are all operating with a fundamentally uncertain input. The question is not whether lightning is changing — the data say it is. The question is whether institutions are building the monitoring and modelling capacity to track changes that move faster than the science.
