So far, there have been 37 very unlucky people in 2024. They’re the ones who went out scuba diving, snorkeling, surfing, or otherwise venturing into the ocean and wound up victims of unprovoked shark attacks. Six of the attacks were fatal; one led to a severed foot; others resulted in varying degrees of various injuries. Thirty-seven is a scary number, especially since summer in the Northern Hemisphere has just begun. Last year, there were 81 unprovoked shark attacks reported worldwide. Since the beginning of the 21st century, the bloodiest year was 2015, when 111 humans—who did nothing to anger the sharks beyond venturing into their waters—came under attack.
All of this information—and much more—is available at the Global Shark Attack File, which keeps a running count and a spreadsheet of human-shark encounters going all the way back to 1845. For the curious, studious, or merely morbid, the spreadsheet records everything from the nature of the injury to the gender of the victim to the species of the shark to the location of the attack, and more. But what most people want to know is less about what happened in decades past and more about what’s going on today: How safe is it for you to venture offshore this summer without winding up as a predator’s dinner? The answer takes some parsing.
For starters, there’s no denying that from 1950 to 2020, the total number of unprovoked shark attacks has risen, going from 50 in the middle of the last century to over 80 in 2020—and reaching that 111 peak in 2015. So sharks are getting meaner or humans are getting more careless, or something else is going on to put the two species in each other’s way, right? Not necessarily.
It’s not just the raw number of shark attacks that makes a difference, but the rate of shark attacks—how many encounters per million people. Back in 1950, the global population was 2.5 billion people. Today it’s just over 8 billion. Crunch the numbers according to the rate of unprovoked shark attacks per million people and things stay pretty flat, with 0.012 per million in 1950 and 0.010 in 2020.
But that’s not to say there aren’t some confounding numbers in the data record that experts are at pains to explain. From 2012 to 2022, for example, there was an average of 12.6 unprovoked shark attacks per billion people on earth, and from 1950 to 1960 the number was 11.8—not much of a difference. Through the 1970s and 1980s, however, the attack rate plummeted, to 6.5 per billion.
It’s tempting to attribute at least part of this to the so-called Jaws Effect, a term coined by Christopher Neff, a public policy professor at the University of Sydney, to explain the overall detrimental effect the movie Jaws had on people’s opinion of sharks—and the untold number of vacationers it drove out of the ocean. Arguing against the Jaws Effect is the fact that shark attacks were already on the decline in 1970—five years before the movie was released on June 20, 1975—with 8.39 attacks per billion. On the other hand, those figures plummeted dramatically in 1976 and 1977—to 5.55 and 3.08 respectively, perhaps reflecting the influence of the movie, and bathers’ avoidance of the ocean.
“The socio-psychological saturation of the film as both a summer blockbuster and a psychological meme is widespread,” Neff wrote in a 2015 paper. “Importantly, many modern representations of sharks mirror elements from Jaws in ways that suggest humans are on the menu.”
But if sharks have gotten a bum rap on screen—and if the actual rate per million of shark attacks hasn’t risen since 1950—that’s not to say we’re not increasing our chances of a nasty encounter when we hit the ocean. As with so many other things, climate change is to blame.
Read more: How Climate Change Is Fueling a Rise in Shark Attacks
One 2016 study in Progress in Oceanography warned that higher ocean temperatures were pushing shark species from the warmer, more sparsely populated southern hemisphere to the cooler, more crowded north—increasing the odds of shark-human encounters. What’s more, higher temperatures also mean more beach-goers and bathers, providing more potential chum for sharks.
“Each year we should have more attacks than the last because there’s more humans entering the water, and more hours spent in the water,” George Burgess, director of the Florida Program for Shark Research, told TIME when the paper was released. More recently, a 2021 study in Scientific Reports blamed climate change—and the sharks’ search for cooler waters—for “unprecedented sightings” of white sharks in California’s Monterey Bay.
No matter how much we’re increasing the risk of humans and sharks running afoul of one another, in a world of 8 billion people, the likelihood does remain vanishingly small of any one person coming under attack. That’s the good news. The bad news is that every year, a handful of people do wind up on the wrong end of those very long odds. The best advice? Swim if you like—but do stay alert.
Write to Jeffrey Kluger at jeffrey.kluger@time.com.
