It was the terrible prospect of lightning one day striking the historic windmill that troubled Andrew Farrell. A bolt five times hotter than the surface of the sun instantly turning moisture in one of the mill’s timbers to steam, exploding it. What if a raging fire then engulfed the 160-year-old building? Perhaps most troublingly, he couldn’t shake the thought that this nightmare might be getting more likely with every passing year—because of climate change.
So Farrell of the Broads Authority, a British public body, decided to get a lightning-protection system installed on Mutton’s Mill, a 19th-century windmill that stands on the flat, wide wetland landscape in eastern England known as the Norfolk Broads.
“These mills stick out as perfect conductors into the sky,” says Farrell. Inside Mutton’s Mill is a rare waterwheel, once used to drain the marshes here for agricultural purposes. The mill itself is a protected historical building measuring 23 meters tall, including its sails. Thousands have been spent on restoring it in recent years.
Now, hooked conducting rods on the ends of the mill’s four sail arms are in place, ready to seize an angry lightning bolt and transmit it harmlessly down to rods buried in the nearby marsh. Farrell is confident this could save the historic structure. Though he adds: “You know, if it gets struck, it’ll probably scare the bejesus out of the owl that hangs out up there.”
According to the UK’s Royal Meteorological Society, for every degree of atmospheric warming, the air can hold about 7 percent more moisture. Warmer, wetter air means a greater risk of thunderstorms and, therefore, lightning strikes, the Society adds. Farrell says that, anecdotally, he has already noticed rising electrical storm activity in Norfolk. Scientists remain uncertain over the extent to which lightning might increase in frequency around the world. But organizations are already taking the threat seriously—and quietly moving to protect buildings and critical infrastructure from future strikes.
Based on information found in online documents, among the bodies currently weighing up the risks is Scottish Water, which has contemplated lightning strikes at biogas sites potentially becoming more likely—such incidents could harm workers or members of the public. The International Civil Aviation Organization has, for its part, considered the possibility of more frequent lightning causing disruption to flight schedules, damaging aircraft, or incapacitating radar towers. Network Rail in the UK also discusses the threat to signaling and electrical equipment on the railways in a presentation document.
And in a 2021 report, National Grid Electricity Transmission, the company that maintains the high-voltage power network in England and Wales, said it had already gathered “evidence that lightning strikes around our assets are increasing in some areas.” While the system is largely resilient at present, the report adds, “consideration of the impact of increased lightning will be required in the future.”
The US Department of Defense also cares about lightning, says Caroline Baxter, a senior adviser at the Council on Strategic Risks. “Something that has gone underappreciated is the risk that military installations face from the effects of climate change—including things like lightning,” she says, noting that some states particularly prone to lightning, such as Louisiana and Georgia, also happen to be home to major military bases.
In 2019, lightning damaged a runway at Offutt Air Force Base in Nebraska. Offutt is the headquarters of US Strategic Command—the organization responsible for nuclear deterrence and global strike capabilities. Baxter highlights a 2021 executive order from President Biden, which mentioned the need to assess climate risks to US military installations. “The clarity that comes with getting a direct order has, I think, paved the way for a lot of movement,” she says.
Referring to aviation in general, Jasenka Rakas at UC Berkeley, who has studied the impact of lightning on US airports, says via email: “We are expecting more lightning and significant impacts on aviation.”
Lightning strikes are often portrayed as freak incidents. But they happen all the time—about 3 million times every day, globally. The cost of damage and disruption caused by lightning is not insignificant. In June, the Insurance Information Institute (Triple-I) in the US noted that the value of lightning-related insurance claims rose more than 30 percent in 2023 compared to the previous year, totalling $1.27 billion. The rise was largely due to higher inflation and construction costs, but Loretta Worters, a spokeswoman for Triple-I added, in an email to WIRED: “We are certainly seeing more storms, which could be a result of climate change.”
The cost of a lightning strike to individual businesses could be “astronomical,” says Tim Harger, executive director at the US nonprofit the Lightning Protection Institute (LPI). He mentions the case of a New Jersey furniture business that was struck by lightning some years ago. “They lost about a million dollars of inventory,” he says.
The LPI recommends that building owners commission an assessment of their lightning risk and consider installation of a lightning protection system that meets current standards, if necessary.
It’s important to note that scientists aren’t sure whether climate change will definitely boost the global frequency of lightning strikes in the coming decades. But some modeling studies do suggest such a trend may be unfolding. In 2014, David Romps—now at UC Berkeley—and colleagues published a study that forecasted the potential increase in lightning strikes in the continental US due to climate change. “It found a substantial increase—a 50 percent increase over the century,” he says.
However, he cautions that this projection was based on “proxies” for lightning—in this case, an increase in storms and, therefore, a likely increase in lightning associated with those storms. One of the problems that comes up when you try to study lightning frequency is the fact that lightning detection systems around the US and elsewhere are always changing.
That network of detectors is gradually getting better, which means that it is possible to detect more lightning. But that also makes it hard to compare detection results from today to those from 10 years ago. And even if you had a stable instrument for reliably detecting lightning across a wide area, it remains difficult to weigh up all the factors that influence lightning incidence and determine whether a warming world really will push up the frequency of strikes. Some projections actually indicate a decrease in lightning by the year 2100. Though, separately, rising incidence of lightning has been noticed in the Arctic during the last four years.
Still, it is logical that owners of important structures want to protect them from electrical storms, adds Romps: “They probably want to protect those buildings anyway, but the expectation of more lightning is just an additional impetus to do so.”
Another study, published last year, found that climate change could drive a noticeable rise in the incidence of lightning-ignited wildfires. “Globally, we obtained a clear increase,” says Francisco Pérez-Invernón at the Institute of Astrophysics of Andalusia in Spain. “For example, in the western coast of America it is quite clear there will be an increase in lightning and a decrease in precipitation.”
That means more dry wood around and more lightning strikes potentially sparking fires. The study also suggested that the risk of lightning-ignited wildfires would rise in the Mediterranean; in Siberia, on the other hand, where wildfires can be massive, there was no overall upward trend.
Pérez-Invernón notes that a specific kind of lightning, called long-continuing-current lightning, is most worrisome in terms of fire ignition, because these flashes can last for tens or even hundreds of milliseconds, depositing huge amounts of energy into combustible trees, for example. It is very difficult to measure this type of lightning, he adds, which means that our understanding of even its current prevalence is pretty murky.
“A single strike can carry 300 million volts of electricity—that’s massive,” says Kimberly Loehr, a lightning protection and communications consultant. Lightning is strong enough to explode bricks or send power surges down electrical lines, potentially damaging plugged-in devices. With the rise of home automation systems, electric vehicles, and wind turbines—the latest at-risk windmills—we have a lot more assets out there that could succumb to a strike, she notes.
Plus, fire protection systems such as sprinklers and smoke alarms may be less useful if your roof gets struck by lightning. People don’t typically have such technology in their attics, says Loehr.
The principle behind lightning protection is that of a Faraday cage, says Roy Westwick, president of the Association of Technical Lightning and Access Specialists in the UK. A system of metal rods and connectors straddle a building and convey the electricity delivered by a lightning strike away from the structure itself or other vulnerable materials. “You’d have a number of routes down to an earth electrode or a ring conductor in the ground,” says Westwick, adding that surge protection for any internal electrical systems is an important additional consideration.
Lightning protection is “a no brainer—use it,” says Mitchell Guthrie, former chair of the US National Fire Protection Association’s Committee on Lightning Protection.
At least Mutton’s Mill, in wildest Norfolk, ought to be safe from now on. “I feel better about it,” says Farrell. “These mills are an iconic part of the Broads landscape. Just as they would be in Holland. If we lost them, where would we be? Those things are irreplaceable heritage.”
