New research says climate change could lead to a new era in baseball with more frequent home runs.
According to the research, published in the journal Bulletin of the American Meteorological Society, the warming planet may be behind at least 500 home runs since 2010. The researchers attribute this new “climate-ball” era to higher-than-average temperatures resulting from climate change.
The researchers analyzed more than 100,000 Major League Baseball games and 220,000 individual hits in order to establish a correlation between the number of home runs and the occurrence of unseasonably warm temperatures.
Rising temperatures could account for ten percent or more of home runs by 2100 if greenhouse gas emissions continue unabated, the researchers found.
“There’s a very clear physical mechanism at play in which warmer temperatures reduce the density of air. Baseball is a game of ballistics, and a batted ball is going to fly farther on a warm day,” said senior author Justin Mankin, an assistant professor of geography at Dartmouth College.
The study’s lead author, Christopher Callahan, said that while temperature is not the dominant factor in the increase in home runs, its effect will only grow by the end of the century if greenhouse gases emissions continue on their course.
“We asked whether there are more home runs on unseasonably warm days than on unseasonably cold days during the course of a season,” Callahan said. “We’re able to compare those days with the implicit assumption that the other factors affecting batter performance don’t vary day to day or are affected if a day is unseasonably warm or cold.”
Callahan said batters are now primed to hit balls at optimal speeds and angles. “That said, temperature matters and we’ve identified its effect,” he said.
“While climate change has been a minor influence so far, this influence will substantially increase by the end of the century if we continue to emit greenhouse gases and temperatures rise.”
The study examined each major league ballpark in the United States to gauge how the average number of home runs per year could rise with each 1°C increase in the global average temperature. They found that Wrigley Field in Chicago would experience the largest spike, with more than 15 home runs per season, while the Tropicana Field in Florida would remain level at one home run or less no matter how hot it gets outside.
Night games and covered stadiums, such as those at Tropicana Field, would almost eliminate the effect of temperature and air density on the distance a ball travels. The researchers also suggest that curbing the rise in home runs, and thus the excitement they bring to a game, might seem counterproductive, but there are additional factors to consider as global temperatures rise, particularly the exposure of players and fans to heat.
“A key question for the organization at large is what’s an acceptable level of heat exposure for everybody and what’s the acceptable cost for maximizing home runs,” said Mankin. “Home runs are one pathway by which temperature is affecting game play, but there are other pathways that are more concerning because they have human risk attached to them.”
The researchers accounted for factors such as the use of performance-enhancing drugs, the construction of bats and balls, and the adoption of cameras, launch analytics, and other technology intended to optimize a batter’s power and distance.
The study began with Callahan, an avid baseball fan, wondering about the effect of climate change on baseball and sports in general.
“It’s important for us to recognize the potentially pervasive way that climate change has altered, or will alter, all the things we care about that are not necessarily encapsulated in heat waves or megadroughts or category 6 hurricanes,” Callahan said.
“Major League Baseball is a multi-billion-dollar industry that is very data-rich, and that privilege allowed us to identify the effect of climate. This critical cultural touchstone for what it means to be American also happens to have a very salient relationship with physics in that temperature actually affects game play,” said Callahan.
Grand Slam tennis tournaments
Research published last year found the four major Grand Slam tennis events also face risks related to the warming planet. According to data from Nate Silver’s FiveThirtyEight platform, climate change could make the outdoor tennis tournaments exceptionally warm — too warm to play.
The models showed that by 2050, the Australian Open temperatures could surpass 105°F, but for the players, it could feel like 147°F. The French Open could see a heat index of 113°F, Wimbledon could feel like 102°F, and the U.S. Open could see a heat index of 145°F.
For baseball, the researchers say that evaluating the impacts climate change can have on cultural institutions such as sports can resonate with people’s daily lives more than large-scale natural disasters such as floods or fires that have increased in recent years as a result of global warming.
“Baseball is one of these ways that American society holds a mirror up to itself and global climate change is just another example — baseball is not immune to it,” study co-author Jeremy DeSilva said.
“This kind of study can be an entry point to understanding a phenomenon that is affecting the planet and every individual on it,” he said. “Maybe people who otherwise wouldn’t have will think about, and have a bigger conversation about, the more impactful and dangerous aspects of climate change once they know how it’s affecting this quintessential game in the history of our country.”
Mankin says it’s difficult to document how climate change is affecting cultural institutions and forms of recreation generally. “For most cultural institutions, we simply don’t have the data,” he said. “In fact, we struggle to track climate impacts around the world because of data poverty. A project like this makes me worry that warming is affecting so many other things we just can’t document.”
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