Kelly Slater and Bianca Valenti test the waves at Slater's surf park in California.
Kelly Slater (left) and Bianca Valenti test the waves at Slater’s surf park in California. The facility is just one of many that have opened around the world to meet the demands of surfing and a quickly changing natural world. Sachi Cunningham

Bianca Valenti belongs to a class of surfers that runs down monster waves, including the legendary Jaws break on Hawaii’s North Shore that sometimes delivers 60-foot swells. She’s also shredded waves around the tenth of that size at a popular surf spot in Lemoore, California, 100 miles away from the ocean.

Since 2018, the Kelly Slater Wave Company (KSWC) has invited Valenti twice to test out their Surf Ranch, a 2,000-foot-long artificial basin powered by a system of hydrofoils that zip along a track to generate waves. The track replicates the infamous “barrel” breaker that curls over and nearly swallows its rider. It’s a sublime, sought-after surf experience that’s hard to find in the world’s oceans, Valenti says.

“It’s a perfect wave every single time,” Valenti says. “In surfing, you don’t get that opportunity to practice one trick.”

It’s the lure of a consistently flawless breaker that’s driven businesses around the world, including KSWC, to develop a range of artificial-wave technologies over the past decade. Forget the dinky, lackluster pools designed for children’s water parks—these multi-million-dollar playgrounds promise riders a sweet surf session without the ocean’s fickleness. Meanwhile, journalists have denounced these facilities as “bleak” and “a satanic mirror,” questioning whether they can host real surf sessions and tournaments.

A diagram of how artificial-wave technology works at the BSR Surf Ranch in Waco, Texas
The tech behind the BSR Surf Ranch in Waco, Texas
1. Twenty-four air pistons at the pool’s rear wall fire sequentially at intervals with only microseconds between them.
2. Each volley can release more than one million pounds of thrust, sending swells of up to 150,000 gallons surging forward.
3. The pool floor imitates rolling undersea topography, pushing the water up and down to increase the waves’ size and power.
4. Breakers dissipate in a 180-degree arc along three sides of the basin, which hold a total of 2.7 million gallons of faux ocean.
5. Surfers rest in the shallows at the edges before paddling out for another ride on waves that can be as tall as they are. Illustration by Stuart Patience

As some of the globe’s top-ranked surfers practice cutback and floater tricks on fake waves, the seas they rode up on now face urgent threats from climate change. Rising temperatures are causing glaciers and ice sheets to melt, water levels to rise, storms to intensify, and marine habitats along many Pacific coastlines to acidify.

These environmental stressors could render surf-able ocean waves even more rare and dangerous. Other outdoor sports have already had to adapt: An unusually warm winter recently pushed Norwegians skiers into an icy hangar, while Alps resorts regularly blast homemade powder across the slopes. But climate change stands to put a unique burden on the surfing community, as iconic breaks may completely transform within a single generation.

By century’s end, approximately 40 percent of the world’s coasts might experience simultaneous changes in wave height, cycles, and direction. In places where heights are expected to decrease, like the north Atlantic and stretches of the north Pacific, erosion along surfer-friendly beaches will likely intensify.

Because these shifts vary by region, the iconic breakers at two popular spots—Maui’s North Shore and California’s Santa Cruz—could face opposite fates: The Hawaiian waves may get larger and more hazardous, while the Santa Cruz swells may flatten out.

Hawaiian breakers on the rise

Ian Gentil crests a wave at the BSR Surf Ranch in Waco, Texas.
Ian Gentil crests a wave at the BSR Surf Ranch. The facility is owned by American Wave Machines, which plans to host a traveling tournament on its US and international properties later this year. Fred Pompermayer

On Maui’s North Shore, the infamous Pe’ahi or Jaws surf spot delivers some of the world’s tallest waves, thanks to a lucky mixture of seafloor contours, incoming storms, and local winds. When storms brew in the north Pacific near Alaska, breakers are pushed thousands of miles toward Hawaii, where they eventually form 60-foot walls that are perfect for risky riding. But as warming temperatures drive more frequent and intense cyclones in the ocean, these rollers may continue to grow. Pe’ahi waves reached an unprecedented 80 feet in 2016 to both the delight and horror of seasoned big-wave surfers.

“Chances are you’re going to see more swells in Hawaii,” says Oceana Francis, an associate professor in the Manoa’s Department of Civil and Environmental Engineering at the University of Hawaii. “We’re trying to pinpoint and measure what wave heights we can predict in the future.”

Francis, who is native Hawaiian and lives in Honolulu, has already witnessed an uptick in ferocious coastal floods that have swallowed sections of beaches and threatened nearby roads.

Coral reefs typically protect these beaches from surges, but more significant for surfers, they produce especially epic rides. Waves rise up from the low depths and “trip” on steep reefs when they break, says Curt Storlazzi, a research geologist at the US Geological Survey’s Pacific Coastal and Marine Science Center. This rapid shift churns out towering swells, which sometimes bend into the tunnels desperately sought by surfers. But with corals enduring devastating mass bleaching events fueled by warming seas, reefs off of Pe’ahi are breaking down, causing large waves to collapse closer to shore, Storlazzi says.

“If that reef degrades, you might lose the protective beach,” he explains.

The Golden State’s new normal

Brianna Cope crests the surf at the Waco park
Brianna Cope crests the surf at the Waco park. While technology has come a long way in the last few decades of the sport, the facilities that adopt them can be resource intensive, especially in terms of water and energy. Rob Henson

Unlike Maui’s North Shore, wave power may actually decrease along Santa Cruz beaches. During California’s peak winter surf season, Pacific storms will probably move northward, Storlazzi says, forcing waves to travel farther to reach the West Coast of the US and shrink incrementally by century’s end.

In fact, unusual weather events have already affected California’s iconic surf locales. Valenti often catches monster breakers at Mavericks, the Golden State’s ultimate wave beach—but this year, she says they’re much smaller than normal. Part of this can be attributed to the “Ridiculously Resilient Ridge,” a stubborn high-pressure system over the Pacific Ocean that prevents storms from reaching California. Researchers have linked the extreme phenomenon with climate change and pinpointed it as a main cause of the 2012 to 2016 California drought.

And though the West Coast’s bedrock won’t degrade as rapidly as Hawaii’s coral reefs, Storlazzi says that sea level rise could nonetheless bring wave breaks closer to shore and aggravate flooding and erosion. One 2017 study predicted that about a third of popular Southern California surf spots will be either “threatened” or “endangered” by 2100 due to ascending waters and their impact on wave quality.

Where surf parks come in

Kevin Shulz catches air at the Waco training grounds.
Kevin Shulz catches air at the Waco training grounds. Critics of surf parks say the faux waves pale in comparison to the power and diversity generated by the world’s oceans. Rob Henson

To that end, the new global trend of surf parks can provide an alternative training ground for pros like Valenti, even if they can never replace the real thing. In Hawaii, local surfer Brian Keaulana is aiming to build a five-acre wave pool on Oahu’s West Side, but there’s talk of how the project could have a ripple effect beyond the sport.

Cliff Kapono, a chemist and pro surfer who’s native to the island of Hawaii, worries about the strain an artificial wave pool would pose on the island’s resources. While businesses like KSWC have employed renewable energy to power their facilities, they still require massive amounts of water. The American Wave Machines (AWM) surf park in Waco, Texas, for example, sources 2.7 million gallons from a nearby well. And though it’s possible to fill these pools sustainably (Surf Snowdonia in Wales recycles water from neighboring mountain reserves), location can be limiting.

Despite his sustainability concerns, Kapono notes that surf parks could work well as a recreational opportunity for underserved communities.

“In the long run, I don’t see it being comparable to the outside,” he says. “People can learn how to have better ocean safety and how to swim. I think it’s more about community engagement rather than relieving environmental pressure on the ocean.”

But most surf parks are currently cost prohibitive. Sessions range from $60 for a one-hour beginner session at the BSR Surf Resort and at least $290 per wave at the Kelly Slater Surf Ranch.

Like Kapono, some surfers recognize surf parks as a valuable training resource in an arsenal of tools. Valenti says it’s a solid chance to practice high-scoring maneuvers without the uncertainty of the sea, where long waits are customary and a good wave isn’t always guaranteed.

These types of stadiums would make sense for pro events, Valenti says, as the ocean sometimes falls flat for around 20 or 30 minutes during televised competitions. AWM plans to host a Stadium Surf Tour at their newer international facilities—it’s scheduled to begin in Texas in October and move to Japan next February.

As the awareness around surf parks grows globally, an unlikely crowd has taken interest: scientists. Wave pools may play a role in combating climate change as researchers model ocean-like swells with the technology these facilities have fostered and perfected. In 2010, AWM developed a wave generator for the University of Texas Rio Grande Valley to study renewable “blue” energy sourced from the seas. Amid a climate crisis, studying fake waves saves time and potentially resources for the larger population.

“With this help, we are more confident that we can reach our ultimate goal—to make ocean waves become a competitive renewable energy source,” University of Texas Rio Grande Valley engineer Yingchen Yang said in a press release.

Kapono, who’s studied coral health in Honoli’i, Hawaii by creating 3-D reconstructions of reefs, says he’d also be excited to simulate the relationship between changing tides and shorelines, particularly to predict future erosion and learn how best to manage it. “Those are the things that really excite me about wave pools,” he says, “even more than doing the turns.”