International scientists agree that temperatures are rising around the world and are expected to continue on this trajectory. Tennis has a hand in it, both as cause and victim: by some estimates, the pro tennis industry releases 60,000 tons of CO2 every year; and the mostly-outdoor nature of the sport exposes players to new, dangerous extremes. It may also be part of a solution.
The effects of rising temperatures were most recently seen at Roland-Garros this year, where record May heat in Paris, surpassing 90F, overshadowed the first week of the tournament. Many players fell victim to the sweltering conditions, headlined by men’s favorite Jannik Sinner losing in the second round after being only one game from victory. The Italian said in his press conference that he “hit a wall” and “could not find any energy.”
Christopher Tyler, reader in environmental physiology at the University of Roehampton in the UK, explains that increased body temperature and heart rate in extreme heat conditions leads to “increased actual and perceived strain,” increasing the likelihood of players covering less distance and attempting riskier shots to try and shorten points, as Sinner resorted to in Paris.
Tyler explains that unlike team sports like soccer, tennis players suffer from more frequent illnesses at similar temperatures because they down-regulate less. “Players still need to cover the court at high speed to be competitive whereas a team of 11 can facilitate recovery breaks in-game,” he says. That’s why, when leading 2-1 in his first round match, Casper Ruud essentially took a break in the fourth set to recover, losing it 0-6: “I was 2-1 [sets] up still and allowed myself to kind of lower the intensity a bit to get my pulse and body temperature down as much as possible in the fourth to see if there was any chance to finish in the fifth and have some extra energy. Luckily, that ended up working.”
Even if players drink regularly during a match in extreme heat, they are unlikely to consume enough fluid to prevent hypohydration — where the body loses more water than usual in a day — which can cause stomach problems. French Open semi-finalist Jakub Menšík felt sick during his second-round match as his body struggled to absorb electrolytes and water. He collapsed after winning match point, calling the conditions “insane” to play in. Post-match, Tyler says that players should drink 1.5x the amount of fluid they lose during a match, estimated as the difference between pre- and post-body masses.
Extreme heat at Roland-Garros is measured using wet-bulb globe temperature, calculated using temperature, humidity, wind speed, sun angle, and cloud cover. When the WBGT reaches 86.2F, players can request a 10-minute break between the second and third sets in women’s matches and third and fourth sets in men’s matches. If the WBGT reaches 90F, the match is suspended.
Despite the temperature exceeding 90F, no matches were stopped at Roland-Garros this year because these WGBT thresholds weren’t met, but AP analysis from 2023 shows that every Grand Slam has been getting hotter over time. Wimbledon and the US Open use the same WBGT thresholds as Roland-Garros, while the Australian Open uses its own heat stress scale that considers radiant heat, air temperature in the shade, relative humidity, and wind speed. Dangerous heat is regularly an issue at Melbourne Park and 2026 was no exception, with play suspended when temperatures reached 104F, allowing Sinner to recover and save himself from suffering a similar fate to Roland-Garros in his third-round match.
The Italian wasn’t so fortunate at the 2025 Shanghai Masters, where he retired with extreme cramps in conditions exceeding 93F and 80 percent humidity. At the same tournament, Novak Djokovic threw up on court and Holger Rune asked an ATP official: “You want a player to die on court?” Daniil Medvedev asked a similar question at the Tokyo 2020 Olympics.
The ATP introduced a new heat rule for the 2026 season, aligning its WBGT thresholds with the Grand Slams, ITF, and WTA—the latter implementing its own heat rule all the way back in 1992 to protect players in extreme heat and humidity. Playing at the same time as Shanghai in October 2025, the WTA suspended play at the Wuhan Open when the temperature and humidity exceeded 87F and 60 percent, respectively.
Although temperatures in Paris, Shanghai and Wuhan are still considered anomalies, climate change is making such instances more common. Professional tennis cannot look away anymore.
Though the terre battue of Roland-Garros represents the standard when it comes to clay, a court of a different color could offer a surprising response to the climate challenge facing tennis.
There are roughly 700,000 tennis courts around the world. Of these, 17,000 are green clay—known as Har-Tru—dotted across the US. They’re often dismissed as somehow sub-par, but green clay courts save the carbon emissions equivalent to taking 4,200 cars off the road every year.
That’s according to research showing thametabasalt rock—the main natural resource used for green clay courts—absorbs carbon dioxide emissions, with 80 percent of the courts generating net-negative carbon emissions within 10 years.
Around 55 percent of the world’s tennis courts are hard concrete topped with acrylic paint, but the paper’s researchers—oceanographer Frank Pavia of the University of Washington and earth scientist Jonathan Lambert of New York University—found that constructing a green clay court emits at least 1.6x less carbon than a hard court.
The Charleston Open WTA 500 is now the only professional top-tier tournament played on green clay. As 2019 US Open champion Bianca Andreescu noted in Charleston this year, green clay occupies a natural position in the calendar as a "great transition to the red clay," because it plays close enough to hard courts that non-clay-court specialists can still be competitive, while developing the movement and tactics that red clay demands.
Though most players prefer playing on red clay, expanding green clay's calendar presence in early spring could make sense for players easing into the clay season.
“We showed in our paper that the green clay courts with the largest carbon removal are found close to the quarry of blue ridge metabasalt in the mid-Atlantic,” says Pavia, “so tournaments whose courts have the greatest carbon removal would be close to there—Delray Beach might be one option.”
The Houston Open—the only ATP tournament at 250 level or above played on clay in the US—could be another (it’s currently played on red clay, which doesn’t have the same carbon-saving effects because it is made from crushed brick instead of metabasalt).
Whether or not the study helps expand green clay courts’ presence in professional tennis, Pavia believes that existing tournaments already being played on the surface—the Charleston Open, but also Challenger events in Sarasota and Tallahassee, for example—publicizing how green clay reduces carbon emissions would offer a small win by helping the public understand the issues of climate and carbon removal.
Another attempt at reducing the sport’s environmental impact is happening with tennis balls. Conventionally, balls are made of an air-filled rubber core covered by glued-on felt and designed to withstand repeated assault by a racquet. This makes them difficult to deconstruct and recycle; more than 300 million balls end up in landfills every year, which can take more than 400 years to decompose.
Instead of recycling, organizations like Circularball, Recycaball, and RecycleBalls collect tennis balls and repurpose their materials for other industries and applications, ranging from dog toys to furniture components. Others have redesigned tennis balls altogether. Launched in 2020, Renewaball sources used balls from European tennis clubs, reutilizing their rubber but swapping conventional polyester and nylon felt covering with biodegradable wool. This reduces microplastic pollution, and means that Renewaballs have a 29 percent smaller carbon footprint than their traditional counterparts.
Though repurposed tennis balls haven’t made their way to the pros yet, the International Tennis Federation (ITF)—the governing body organizing competitions including the Davis Cup, Billie Jean King Cup and tennis at the Olympics—is developing a prototype without a fabric cover. An ITF spokesperson says they “hope to be able to announce more details publicly” about it in the coming months.
Other systemic changes to tennis' globetrotting 11-month calendar may also be necessary. The 2026 ATP and WTA tours feature more than 50 tournaments (250 level and above) in almost 30 countries. Masters 1000 tournaments, such as Shanghai and Wuhan, are now two-week affairs akin to the four Grand Slams, expanding the calendar and exacerbating heat, injury and burnout risks facing players. In fact, new events are being added to the calendar, with a new ATP Masters 1000 tournament in Riyadh, Saudi Arabia set for 2028, reflecting the heavy investment of Saudi Arabia's Public Investment Fund in tennis.
Almost ninety percent of the ATP’s carbon footprint comes from travel, which CEO Eno Polo named the organization’s “number one environmental challenge.” In 2023, the governing body released a carbon tracker, so players can keep tabs on their travel over the course of the season. More than 300 players participated in its first three seasons.
In 2025, American Mackenzie McDonald topped the rankings for the second time, saying that the tracker “has helped me understand the impact of traveling between tournaments, allowed me to practically make more responsible choices, and shown me that even small changes add up.” Across the season, players tracked a combined 2.3 million kilometers of travel and offset 585 tons of carbon.
Professional players have the platform to inspire behavior change, but remain well aware of appearing hypocritical by talking about the environment while travelling around the world to play tennis. While the ATP hopes the tracker will encourage more sustainable travel, this is a much simpler proposal during, for instance, the European clay season. The multicontinental back-and-forth nature of the rest of the calendar makes air travel largely unavoidable; in fact, many top ranking players forgo commercial flights for more carbon-intensive private travel to increase efficiency.
It’s hard to look earnestly upon the organization’s sustainability efforts when it’s sponsored by the likes of Emirates, recently extending the airline as a Premier Partner through 2030. Given that the airline also sponsors all four Grand Slams, the cynic wants to ask: are the sport’s governing bodies creating publicity about addressing climate change as a marketing ploy—rather than reflecting tangible action—to obscure lucrative deals with fossil fuel companies?
The fractured nature of the ATP, WTA, ITF, and four Grand Slams makes collective action more difficult than it needs to be. Each organization protects its own interests, but this seldom aligns with the most important stakeholder: the players. The Professional Tennis Players Association has advocated for changes like reducing the number of events and giving players more freedom to choose which events they play, but as long as players’ interests fall below those in power, it’s unlikely that tennis will proactively change fast enough before it is forced to. In the meantime, green clay and better balls offer a hopeful glimmer as we sweat out summer 2026.
George Timms is an English journalist. When not writing, he can be found chasing the feeling of a perfectly hit one-handed backhand.
