Is Baseball Feeling the Heat of Climate Change? A New Study Reveals How Rising Temp is Shaping the Future of America’s Favorite Pastime

Throughout the history of Major League Baseball, we have seen the low-scoring dead-ball era, followed by the live-ball era marked by power hitters like Babe Ruth and Hank Aaron. Then, there was the unfortunate steroid era of the 1990s and early 2000s.

But now, is baseball about to enter a new “climate-ball” era where the outcome of a game is increasingly influenced by higher temperatures due to global warming?

According to a recent study from Dartmouth College, the onset of a “climate-ball” era in baseball may be imminent. The study, published in the Bulletin of the American Meteorological Society, suggests that over 500 home runs hit since 2010 can be linked to higher temperatures brought about by climate change.

The research also indicates that if greenhouse gas emissions and climate change are not addressed, rising temperatures could account for 10% or more of home runs by 2100, with several hundred additional home runs per season likely.

Although the study links only 1% of recent home runs to climate change, it suggests that the impact of rising temperatures on the game of baseball may be significant in the future.

“There’s a very clear physical mechanism at play in which warmer temperatures reduce the density of air,” comments senior author Justin Mankin.

“Baseball is a game of ballistics, and a batted ball is going to fly farther on a warm day.”

The study conducted by Dartmouth College researchers involved analyzing more than 100,000 Major League games and 220,000 individual hits. Their objective was to establish a correlation between the number of home runs and unseasonably warm temperatures. They then estimated the extent to which the lower air density resulting from higher temperatures played a role in the number of home runs hit on a given day in comparison to other games.

The lead author of the study, Christopher Callahan, who is also a doctoral candidate in geography at Dartmouth, stated that the researchers took into account 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 enhance a batter’s power and distance.

“We asked whether there are more home runs on unseasonably warm days than on unseasonably cold days during the course of a season,” explains Callahan. “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.”

“We don’t think temperature is the dominant factor in the increase in home runs — batters are now primed to hit balls at optimal speeds and angles,” Callahan adds. “That said, temperature matters and we’ve identified its effect. 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 researchers conducted an analysis of each major league ballpark in the United States to determine the extent to which the average number of home runs per year could rise with each 1-degree Celsius increase in global average temperature. However, the actual number of runs per season could be either higher or lower depending on individual game day conditions.

According to the study, Wrigley Field, which hosts only a limited number of night games, would experience the largest increase in the number of home runs per season, with more than 15 expected, while the domed Tropicana Field of the Tampa Bay Rays would remain level at one home run or less regardless of how hot it gets outside. Fenway Park of the Boston Red Sox and the home of their archrivals, the New York Yankees, would experience a similar effect as temperatures rise, falling somewhere in the middle of the spectrum.

According to the researchers, night games would reduce the impact of temperature and air density on the distance a ball travels, while covered stadiums such as Tropicana Field would almost completely eliminate it. Although limiting the increase in home runs may seem counterproductive to the excitement they bring to a game, there are other factors to consider as global temperatures rise, such as the exposure of players and fans to heat, said Mankin.

“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,” Mankin adds. “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.”

Mankin stated that the extensive data available for major league baseball games presented a rare chance to detect the effects of climate change on a cultural institution. Climate scientists usually concentrate on the higher probability and severity of natural calamities like hurricanes, floods, and heat waves due to their extensive destruction and the availability of records to study them.

“Major League Baseball is a multibillion-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,” Mankin adds.

“It is really difficult to document how climate change is affecting cultural institutions and forms of recreation generally,” according to him. “For most cultural institutions, we simply don’t have the data. 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.”

Christopher Callahan, an avid baseball fan and lead author of the study, initiated the research by questioning the impact of climate change on sports. According to him, it’s important to realize how global warming has or will affect all the things we cherish that may not be directly linked to heat waves, droughts, or severe hurricanes.

“The effects of global warming will extend throughout our lives in potentially subtle ways.”

Jeremy DeSilva, a professor and anthropology department chair at Dartmouth who co-authored the study, notes that assessing the impact of climate change on cultural institutions can have a greater impact on people’s everyday lives than large-scale disasters that can seem random and out of control. This understanding can inspire change. In the past, baseball has been a catalyst for social change, from desegregation to the increased influence of money and corporatization.

“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,” DeSilva points out.

“This kind of study can be an entry point to understanding a phenomenon that is affecting the planet and every individual on it. 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.”

According to co-author Nathaniel Dominy, who is the Charles Hansen Professor of Anthropology at Dartmouth, cultural institutions are a reflection of societal values, and baseball can be seen as an embodiment of the American response to climate change.

“Think about the expression of American cultural values in baseball and how many of them exist in opposition to the other: winning and losing, tradition and change, teamwork and individualism, logic and luck,” he adds. “These same tensions are frustrating our collective response to carbon emissions, so it is extremely fitting to explore the effects of climate change on baseball. It is a potent metaphor for the American experience.”

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