The TLDR: An astonishing 76 people have died due to lightning strikes over recent days—including 40 over the course of just 24 hours. Eleven died posing for selfies on a watch tower at Amer Fort, Jaipur. Actually, none of this should be surprising. Of those who die due to forces of nature in India, lightning is the number one cause of death. We take a closer look at this invisible killer—and why it has grown more lethal due to climate change.  

Lightning: A back-to-school recap

The how: Lightning is a massive discharge of electricity generated in giant moisture-bearing clouds. To sum up, ice particles collide in these clouds—which results in the top layer of the cloud becoming positively charged, while the bottom layer is negatively charged. A massive current—of the order of 100,000 to a million amperes— starts to flow between the layers, which heats up the air between the two layers. This gives us shock waves that we call thunder. And part of that giant electrical current heads down to Earth in the form of lightning. Point to remember:

“[A] bolt of lightning can pack between 100 million to 1 billion volts of energy and ‘contains billions of watts’. Not only that, a lightning strike can also heat up the surrounding air to anywhere between 10,000 degrees Celsius to 30,000 degrees Celsius.”

Kinds of strikes: There are three main ways lightning strikes a victim:

One: A direct strike is where a person is literally hit by lightning. The person becomes a part of the “main lightning discharge channel”—and what kills isn’t the heat that can cause burns, but the electric current itself. Most often, direct strikes occur in open areas.

Two: Side flashes occur when lightning strikes a taller object near the victim and a portion of the current jumps from the taller object to the victim. The person essentially acts as a “short circuit.” This most often happens when someone is within a foot or two of the object, say, sheltering under a tree.

Three: When lightning strikes a tree or other object, much of that energy travels outward and along the ground—and creates a ground current which travels through your body. Because it covers the most area, a ground current also kills the most number of people.

Ok, how many people die like this?

You’d be surprised. Lightning strikes killed 1,619 people between April 1, 2020, and March 31, 2021. Data from 2019 shows that 8,145 people died due to “forces of nature” that year—of which 35.3% deaths were due to lightning, 15.6% due to heat/sun stroke—and only 11.6% due to floods. On Sunday, nearly 76 people died in a single day in Uttar Pradesh, Rajasthan and Madhya Pradesh. And the death toll is rising over the years:

“Lightning strikes have killed nearly 2,000 people every year in India since 2004, which is nearly twice the number of deaths recorded since the late 1960s… In 2019, there were 2,876 deaths due to lightning compared to less than 1,500 on an average, annually, between 1968 and 2004.”

Also more frequent: From April 2020 through March 2021, over 18.5 million lightning strikes were recorded in India. There has been a 34% rise in strikes—rising from 13.8 million strikes in 2019-20. Also this: Lightning strikes have increased by 30%-40% since the early- to mid-1990s. In 2018, Andhra Pradesh recorded 36,749 lightning strikes in just 13 hours.

Key point to note: The mortality rate from tropical cyclones has reduced by 94% in the past 20 years, but increased by 52.8% for lightning.

But why are so many people dying like this?

Only 4% of these deaths occur in urban areas. They are most common in rural India—where farmers are out in open fields, especially during the pre-monsoon or early monsoon. At other times, they are often killed taking shelter under a tree or because tin-roofed huts. According to a 2019 government report:

“[S]tanding under a tree is the number one primary cause of lightning deaths in India causing 71% fatalities, 25% were a direct hit and 4% indirect hit. As per the circumstances of lightning victims, 51% died while farming in open fields, 37% standing under a tree and 12% inside kutcha huts.”

And climate change is a factor?

Yes, as always. Thunder clouds require heat and moisture in the air to form, according to climate experts:

“Both surface temperature and moisture levels have increased significantly in recent years. Urbanisation leading to loss of tree cover also contributes to rise in surface temperature. We think the two have mainly contributed to the rise in incidence of lightning.”

Scientists predict a 12% increase in lightning activity for every 1°C of warming—and that’s not good news for us. Environmental Journal notes:

“The last decade has been the hottest in India since records began, with temperatures averaging 0.36°C above normal. The rising temperatures have also been linked to frequent heatwaves followed by delayed but more intense monsoons, with deadly lightning strikes now expected by those who live there.”

Data point to note: A preprint study predicts that the frequency and intensity of lightning strikes in India will increase by 10-25% and 15-50% by the end of this century—with coastal areas at the highest risk.

The bottomline: The message with every natural calamity remains consistently the same: If we don’t change the way we live with nature, the more likely we are to die due to it.

Reading list

Hindustan Times and Down To Earth have the best overviews of the rise in lightning strikes—and the causes. Indian Express and Firstpost have more on the how and why of lightning strikes. Times of India has data on who dies in these strikes. You can also check out the Annual Lightning Report for 2020-21. Eos explains how a rising number of lightning strikes can drive further global warming. Smithsonian magazine has more on how climate change is triggering an unusual number of strikes in the Arctic.