How climate change is reshaping how we play warm-weather sports


From bad refs to brain-eating amoebas: How climate change is reshaping warm-weather sports

At the Australian Open in 2020, multiple tennis players withdrew from the tournament after breathing in the thick smoke pouring across the country from out-of-control wildfires. Organizers of the 2020 Tokyo Olympics moved their marathon 500 miles north to an entirely different island to avoid the capital city’s extreme heat. The 2017 hurricane season devastated several cricket stadiums in the Caribbean, where the sport amounts to a national religion. And in the late 2010s, the Texas Rangers built a billion-dollar stadium with climate control and a retractable roof to address rising temperatures.

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This is just a smattering of the ways the changing climate is affecting the world of sports. Some are obvious, such as the threat extreme heat poses to both the performance and safety of athletes; others are more subtle, like drought-induced dust hindering distance runners’ training. But many are happening now, changing the way sports are played, altering the timing of events and playing seasons and affecting athletes’ achievement and well-being. The shifts are happening at all levels of athletics — from recreational leagues and weekend warriors to the pros.

The changes won’t be all bad — for example, it turns out baseballs travel farther in warmer, more humid air, so hitters might not complain (though pitchers can’t be thrilled). But things will be different: different playing surfaces, different equipment, a different environment in general. For athletes used to their sport existing in a certain world, those differences can be disconcerting and potentially dangerous.

“Climate change today is altering sport as a whole,” said Jessica Murfree, a visiting assistant professor of health and kinesiology at Texas A&M University who researches the intersection of climate change, extreme weather and sports. “It’s not ‘climate change is going to change the future of sports’ — that is true, but also climate change is actively altering the sport experience at all levels right now.”


It’s not just winter sports like skiing and hockey at risk, although without snow or ice, many simply can’t be played. Warm-weather pursuits — joining a rec soccer league, running a marathon or attending a Major League Baseball game — are also under threat to varying degrees. With an eye on timing, gameplay, performance and safety, Grid examined how climate change is reshaping our favorite warm-weather sports.

Illustrated map of Japan with a starting point in Tokyo and an endpoint in Sapporo

Timing — and location — is everything

Summer in Tokyo can be sweltering. Daily high temperatures in August average in the high 80s and routinely soar well beyond that. And it’s definitely getting hotter: According to NASA, average temperatures in Japan’s capital city have gone up by 2.7 degrees Fahrenheit since 1964 — three times the global average.

For organizers of last year’s Olympics in the Japanese capital, that meant some logistical maneuvering was required. Officials moved the marathons and walking races to Sapporo, more than 500 miles north, where average temperatures in the summer are about six degrees cooler. Imagine the 1996 Atlanta Olympic marathon being held in, say, Indianapolis, or 2024 host Paris sending the race up to Glasgow, Scotland. But even that is not always enough in a world where extreme weather is becoming more common.

On Aug. 7, 2021, when the Olympic marathons took place, Sapporo was in the grip of a two-week heat wave. Though temperatures during the race did not stray from the high 70s and low 80s, the humidity at race time was 80 percent, which can lead to severely elevated internal body temperatures in an athlete undergoing extreme exertion. Fifteen of 88 competitors ended up withdrawing from the women’s race, as did 30 of 106 athletes in the men’s competition, even though both races were underway by 7 a.m. local time.

Moving events around may start to get more common as temperatures warm, but in many cases ensuring good conditions will also mean shifting their timing. Take cricket, the world’s second-most-watched sport, which is played in some of the hottest and stormiest places. It is wildly popular in India, Pakistan, various islands in the Caribbean and Australia. Some of the latter country’s most iconic matches traditionally take place in the southern hemisphere’s summer, with increasingly dangerous results — in part because of heat, and in part because these competitions can take up to five days to complete.


In January 2018, England’s team captain Joe Root was hospitalized after temperatures in Sydney hit 108 degrees Fahrenheit during the final day of that year’s Ashes — a tournament that has pitted England against Australia at least every two years since 1882. Warming temperatures are also forcing officials to consider changes to traditional schedules. For example, Melbourne’s Boxing Day Test, played the day after Christmas and considered “the jewel in Australian cricket’s crown,” should now potentially be moved out of summer to the shoulder seasons of spring or fall, one recent report suggested.

Cricket is particularly vulnerable to weather extremes simply because of major matches’ lengths. Standing out on a boiling pitch for three, four or five days on end does make moving to a cooler season sound reasonable. Other endurance sports face similar timing concerns. A study published in March found that the pool of potential Summer Olympics cities that could feasibly host the marathon will decline by 27 percent by late this century. The authors recommended either moving the marathon to other sites — as was done in Tokyo and Sapporo last year — or holding the event in October instead of August.

An animated illustrated cricket bat with a thermometer in the center and the temperature is rising

Mike Tipton, a professor of human and applied physiology at the University of Portsmouth in the U.K. and an expert on the effects of extreme environments on human and athletic performance, has participated in triathlons for many years. “The last triathlon I did, in Nice — they had to change the distances because it was too hot to do a 180-kilometer cycle and it was too hot to do a 40-kilometer run. Well, that’s no longer an Ironman Triathlon.”

Sometimes it gets worse than that: In 2019, the New York City Triathlon was canceled rather than subject athletes to increasingly extreme July temperatures. The temperature on race day reached 99 degrees, with 65 percent humidity; the city could see a tripling of days above 90 degrees, from an average of 18 per year to 57 per year, between the 1971-2000 period and the 2050s.

This year, what may be the world’s biggest sporting event will be played in an unusual place at an odd time of year: The World Cup is headed to Qatar in November and December. To be clear, the desert nation poking out into the Persian Gulf was never a reasonable choice for a primarily outdoor, summer event. (Perhaps unsurprising to those familiar with international soccer governance, the unfortunate choice was the result of bribery, according to the Department of Justice.) But Qatar is warming just the same, and faster than many other parts of the world.

Even outside of illogical desert countries, though, more traditional World Cup host cities are seeing the conditions for high-level soccer deteriorate as temperatures rise. For example, Paris first hosted the tournament in its third-ever iteration in 1938, and it hosted again 60 years later. The city’s temperature has gone up around two degrees Celsius (3.6 degrees F) over the 1951-1980 average, well above the global average rise.


And if it is getting too hot for elite, world-class athletes to play the sport, imagine what it is doing to all the amateurs and kids out there.

“There are billions of children who play soccer with the hopes of making the World Cup,” Murfree, of Texas A&M, told Grid. “Their opportunity is diminishing because of the environment.”

Altering how games are played

Very few sports are immune to the ways the changing climate can impact gameplay. From soaring baseballs to stickier artificial turf to flooded pitches and stadiums, a warming climate is taking the simple pleasure of the sports you grew up playing and watching and tweaking them. And some tweaks are more surprising than others.

The rising seas will pose serious risks to coastline everywhere. In California, one estimate suggests that even one foot of rise, which may arrive not long after 2050, will put $15 billion of property at risk and will affect 38,000 people. One might not expect, though, that a rising sea could endanger one of the state’s iconic sports — surfing.


Whether waves are surfable depends on the relationship between the tide and sea level with the rocks and sand of the ocean floor beneath. As the sea rises, the waves in a given spot will change — often for the worse, when it comes to surfing — barring any shifts in the ocean floor. Imagine a beach where the perfect surfing wave is most likely to appear at a medium tide level. A higher sea level will produce the same wave at low tide. But as the ocean level rises, even the lowest tide will be just too deep to produce the surfable wave. This phenomenon could be remarkably widespread: By one measure, three feet of sea level rise will ruin an astonishing 80 percent of the surf breaks in California.


“There’s a range of natural disasters that are impacting on sports, from floods, to fires, to storms,” said Madeleine Orr, a lecturer in sport business at Loughborough University in London and founder of the Sport Ecology Group, an international consortium of academic researchers.

In the U.K., where the Premier League reigns supreme, increasing precipitation and sea level rise are making soccer a much dicier prospect. By one estimate, about one-quarter of major stadiums in the U.K. should expect at least partial flooding every year by 2050. It’s already happening to some sites: League Two team Carlisle United saw its grounds flood in 2015 thanks to Storm Desmond, a huge rainfall event that a study showed was made as much as 59 percent more likely thanks to climate change.

Increasingly devastating hurricanes are also an issue for stadiums and surrounding infrastructure, in particular in the Caribbean, where cricket rules. The one-two punch of hurricanes Irma and Maria in 2017 damaged several large cricket stadiums in Anguilla, Antigua, Dominica and elsewhere in the region, an event that is likely to repeat itself as hurricanes get stronger, drop more and more rainfall, and even weaken more slowly once they hit land.

submerged golf cart

In the U.K. and elsewhere, another potential victim is golf: Courses are often built directly along vulnerable coastlines. With only a few feet of sea level rise, even the birthplace of the sport itself, in St. Andrews, Scotland, may be underwater. The Old Course, where golf has been played since the early 15th century, is one of many Scottish courses at risk of inundation in the coming years; by one count, as many as 1 in 6 of Scotland’s 600 golf courses faces such a future.



But not all coastal sports infrastructure was built half a millennium ago. At the professional level, basketball is among the sports most insulated from climate impacts — unless you’re a team with an arena down by water. With only two feet of sea level rise, the Miami Heat’s $213 million arena, opened in 1999 on Biscayne Bay, will start to flood.

Timothy Kellison, an associate professor of kinesiology and health at Georgia State University, has examined how climate impacts may influence stadium use, and he told Grid that while it is still rare, there are examples of team owners using those impacts — if less than explicitly — to justify building a new stadium. One recent such case is Globe Life Field in Arlington, Texas, where the MLB’s Rangers play.

“They didn’t say ‘climate change,’ but that probably is not going to go very far in Texas,” Kellison said. “But they certainly talked about, you know, people don’t want to go sit out in the hot sun in Texas summer and watch the Rangers, even when they’re good.” (They … are not often good.)

Like Qatar, Texas in summer is an already hot place that is getting much hotter. Average daily temperatures have risen by 2.2 degrees F over the last century or so, and nighttime temperatures across much of the U.S. are rising even faster than days, so the retractable roof on the new stadium — built only a couple of decades after the previous stadium, with $500 million in taxpayer money — will undoubtedly get a workout.

In New York, the U.S. Open tennis tournament added a roof to the main stadium at Flushing Meadows after five straight years saw final matches interrupted by rain delays. The roof was at least partially a response to the increasing likelihood of such streaks: New York has seen total annual precipitation increase over the last several decades (as the atmosphere warms, it can hold more moisture, which comes down in more intense rainstorms), and the biggest rainstorms will become more frequent in the coming years.


While sports need arenas and stadiums and fields in order to play, they also need some fairly specific equipment — and even that is occasionally under threat. Though other types of wood such as maple and birch have become more popular over the years, ash has long been used for bats in Major League Baseball. Enter a gloriously iridescent green insect, the emerald ash borer. Native to Asia, it has invaded North America and Europe, and laid waste to ash trees; its range continues to expand as the climate warms.

Even when the changing climate doesn’t serve up devastating extreme weather, it can render some aspects of a sport all but untenable. “We play on water-based pitches currently,” said Tess Howard, a field hockey player with the England and Great Britain national teams, referring to the way that the playing surface is nearly flooded to allow for smoother game play. “India is a classic example, because you’re either in monsoon season, so the pitch is flooded, or you’re in extreme heat, so you have to keep flooding the pitch with water in a country that’s already got huge inequalities.”

India and Pakistan suffered through an extreme heat wave this spring, an event made 30 times more likely by climate change, and significant portions of both countries lack consistent access to water.

Athlete performance and safety

Even if the pitch is dry, the stadium unflooded and the equipment available — the athletes themselves can’t ignore the threat, either.

When Amy Steel walked into an arena six years ago for a preseason netball match, she was already wondering why her team was playing at all.


“It just felt like you were going into either a Bikram yoga or like a steam room or something,” she told Grid. “It was just so stinking hot in there.”

Steel was an elite, international-level netball player, a sport that resembles basketball without the backboard and is the most popular women’s sport in Australia. Speaking via Zoom from Perth, where she lives, Steel said her team had spent part of this particular day outside already, signing autographs and taking photographs as temperatures soared to 104 degrees F, before heading into an arena where the air conditioning was not working. The game went ahead anyway; it wasn’t until afterward that things went south.

“By the time I got myself into the ice bath, that’s when things started to feel really like something wasn’t right,” Steel said. “I could remember actually asking my teammates, ‘Is it cold? Or is it hot in here? Like, what’s the temperature of this?’ Because I just couldn’t compute.”

She made it through the ice bath and a shower, and out into the parking lot — and then she collapsed. That’s all she remembers until some time later, when doctors explained that she had heat stroke and almost died. And the ordeal did not stop there. In fact, that preseason game, at age 27, was the last netball game she ever played.

“I’ve never been able to play sport again since that day. I can’t even jog or, you know, [play] even like a social level,” said Steel, who has since joined a U.S.-based group called EcoAthletes that helps athletes around the world push ahead with climate activism. “Getting out of bed some days, it’s still a struggle. [And] this is many, many years later.”


Illustration of a runner with fire inside and on their heals

Heat-related illness is the most obvious and visible of climate change’s safety-related impacts on athletes. A warmer world means more heat waves and higher humidity, and athletes outside — or inside without proper air conditioning — running around for hours at a time is getting harder and more dangerous.

“Even sitting at rest, we’re producing about 90 watts of heat,” said Tipton, of the University of Portsmouth. “As we exercise, that can go up to two kilowatts. So that’s a two-kilowatt fire inside of you, effectively.” Normally, the body can compensate for that increasing heat, in part by sweating. But as temperatures increase, and humidity rises as well, things can get dangerous. The so-called wet bulb temperature incorporates both heat and humidity, and it reflects the human body’s ability to cool itself down. If the water content of the air around us makes it more and more difficult to evaporate off our sweat, then we can start to overheat. Beyond a certain point, it is simply no longer survivable. And as Steel’s experience shows, even when athletes survive heat stroke they can face long-term consequences.

But even before heat stroke sets in, high temperatures can have an effect on athletic performance. Even just feeling warmer can reduce an athlete’s output: One 2019 study found a 9 percent decrease in the time-to-exhaustion for elite cyclists when a heat pad was attached to their backs, an experiment that didn’t actually raise the athletes’ core temperature.

Jordan Marie Brings Three White Horses Daniel, a runner and Indigenous activist from the Lower Brule Sioux Tribe in South Dakota, said that she has seen significant changes in conditions at long-distance events that she has returned to a decade or more since her first entry there. “As an athlete, you’re trying to adjust; you’re trying to add in heat training, humidity training, you’re trying to adapt for all of these things,” she said. “I feel like a lot of people think it’s an isolated incident, but it’s not.”

That’s true even for sports that aren’t considered endurance events, or where running or other cardiovascular exercise is a central component. “Every pitch just takes that much more out of you” in high temperatures, said Brent Suter, a pitcher for the Milwaukee Brewers and an environmental activist also affiliated with EcoAthletes, before a late-May game against the Chicago Cubs. “Recovery in between innings is that much more imperative. Recovery after games — sometimes you just go and sit in the cold tub for 10 minutes and just try to get your body back to equilibrium,” he said. “It can get gnarly out there.”


The athletes are struggling to perform, the spectators are sweating it out in the stands — and the umpires or referees are likely adding insult to injury. “In addition to all those physical, physiological and pathophysiological consequences, there are also cognitive and psychological [effects] — and they really shouldn’t be regarded separately because they feed into each other,” Tipton said.

If you’ve ever yelled at the television while watching a baseball game on a particularly hot day, you might have had a point. One study found that temperatures above 95 degrees F were associated with umpires making 5.5 percent more errors in calling balls and strikes when compared with their performance in temperatures between 70 and 80 degrees. With around 300 total pitches thrown per game, that sort of difference could have real effects on game outcomes.

Research in other sports has borne this out. Think of a soccer referee running the field for 90 minutes: In hotter temperatures, as the referee gets hotter and more tired, more of their resources are diverted to muscles and physical motion and away from cognitive processes. Would that penalty kick in the 88th minute have been called the same in the 12th minute, or in a world without some extra degrees piled on?

Animated illustration of a sweating referee

But climate change isn’t just a problem for participants in professional sports. “Climate and its associated hazards are already the leading cause of injury among youth athletes, already the leading cause of death among youth athletes in the U.S. and other parts of the world,” Orr, of Loughborough University, told Grid. “And it’s not getting anywhere near the level of attention it should be receiving.”

Sports-related exertional heat stroke deaths have more than doubled since the 1970s, and heat illnesses were the third-most-common cause of death among high school and college athletes between 1990 and 2020. Some sports, like football, are particularly risky, given the time of year they are traditionally played and the level of padding and gear that players wear.

“If you stop all the heat leaving the body by wearing protective clothing, and you ask somebody to exercise moderately, they’ve got an estimated survival time of around 20 minutes,” Tipton told Grid, mentioning sports like fencing where athletes are sometimes covered nearly head to toe.

Heat-related deaths among football players have been steady over the last decade or so though, which experts say likely reflects the increasing awareness and education surrounding warming temperatures and their danger.

Climate change can also worsen air quality and pollution, with knock-on effects for athletes. The Australian Open, itself commonly affected by Melbourne’s scorching mid-January temperatures, now also has to contend with smoke from wildfires. In 2020, a historic wildfire season in the country burned more than 42 million acres (an area around the size of Florida), destroyed thousands of homes and other buildings, and killed dozens of people. Research suggested that climate change made the fire season at least 30 percent more likely — a “conservative” estimate — and that such seasons will get even more common in the future.

At the Open, the smoke choked several days of play, causing some athletes to retire from matches and even the sport’s best to ponder whether anyone should be playing at all until the smoke cleared. Later that same year, Major League Baseball was forced to postpone and move two games due to wildfire smoke. “I’m a healthy 22-year-old,” the Oakland Athletics’ starting pitcher Jesús Luzardo told the New York Times. “I shouldn’t be gasping for air or missing oxygen. I’ll leave it at that.”

Climate change-induced drought can also make air more dangerous. In Kenya, which along with other East African countries has traditionally dominated long-distance running and marathons, elite runners tend to train in groups of a dozen or more. And Kenya is in the midst of a historic drought.

“If you’re at the back of a 20-person pack, yeah, you’re taking [in] a lot of dust that you wouldn’t have had it not been a drought,” said Orr, who is working on a book about climate change’s impacts on sports, adding that there has been an increase in the incidence of illnesses such as bronchitis in those regions. “If those athletes can’t compete and train the way they want to compete and train because it’s too dusty and it’s too hot? That’s a problem for the pipeline, and that’s a problem for the whole country’s sense of what they’re good at.”

Illustration of a brain-eating amoeba in the brain

Even outdoor activities that toe the line between sports and recreation are seeing some potentially terrifying impacts. The incidence of the pathogen known commonly as a “brain-eating amoeba,” or scientifically as Naegleria fowleri, is increasing with warming temperatures. The amoeba, for which there is often very little potential treatment, can enter the body through the nose in water from lakes and other freshwater sources. Infection is usually fatal. In areas where the amoeba is present, recreational boating, swimming and other activities could put people at risk. And while that risk was originally only in a few southern parts of the U.S., the range is expanding to states as far north as Michigan.

“It’s going on a walk, it’s hiking, fishing, rock climbing, a lot of recreation and leisure, all of these things that have this innate connection to the environment in which they’re being held,” said Murfree, of Texas A&M. “What does that mean for human beings as a species, to be able to continue to do these things and provide for our health and well-being if we can’t breathe the air outside?”

The problem, of course, is not going away any time soon. After a slight pandemic dip in 2020, the world churned out the most greenhouse gas emissions in human history last year, and the atmospheric concentration of carbon dioxide recently hit levels not seen since the Pliocene era, between 4.1 and 4.5 million years ago. If your favorite sport hasn’t seemed to suffer enormous climate-related impacts yet — just wait.

More gameplay weirdness, cancellations and shifting calendars, and safety issues are bound to crop up across the world of sports, whether it’s the increased injury risk of playing cricket on a hard, drought-baked pitch in India or cycling in a race on literally melting tarmac through southern Spain. And experts say it’s time to have the hard discussions about what comes next.

“What is this culturally going to feel like when we lose this? Because that’s what we’re facing,” Orr said. For example, she said, “We are facing no football in the South until late October, because that’s when hurricane season is going to let it happen. I don’t think Louisiana wants to have that conversation yet. I don’t think Texas wants to have that conversation yet. But if we want to keep athletes healthy, we have to.”

Thanks to Lillian Barkley for copy editing this article.

  • Dave Levitan
    Dave Levitan

    Climate Reporter

    Dave Levitan is a climate reporter for Grid where he focuses on interconnected stories about climate and science, and politics shaping action around both.

  • Alex Leeds Matthews
    Alex Leeds Matthews

    Data Visualization Reporter

    Alex Leeds Matthews is a data visualization reporter at Grid.

  • Anna Deen
    Anna Deen

    Data Visualization Reporter

    Anna Deen is a data visualization reporter at Grid.

  • Matt Stiles
    Matt Stiles

    Senior Data Visualization Reporter

    Matt Stiles is the senior data visualization reporter for Grid.