Even America’s favorite pastime is not immune from climate change. A new study from researchers at Dartmouth College says that a warming atmosphere could be causing more home runs in professional baseball.
The research, published last week in the Bulletin of the American Meteorological Society, looked at 100,000 Major League Baseball games and found that at least 500 home runs since 2010 can be attributed to climate change.
As the planet warms, the authors predict that climate change could be responsible for nearly 10 percent of all home runs by 2100, with each degree of warming associated with 95 more home runs per season. Eventually, the report concludes, several hundred additional home runs per season could be due to climate change.
The paper was born out of Callahan’s interest in baseball as a Chicago Cubs fan as well as his background in climate science.
“I was very much raised on baseball, and it’s something I still follow pretty closely and care about,” said Callahan. “I also think about climate change from my day job. And so I inevitably started thinking about those two things together.”
Baseball isn’t the only sport that will be impacted by climate change. Tennis also might be a casualty of a warming world, as well as soccer, both mostly outdoor sports played in heat centers such as the Australian Open in Melbourne or last year’s World Cup in Qatar.
But those sports, so far, lack the data. The Dartmouth study relied on baseball’s tradition of obsessively recording every statistic.
“Baseball has this kind of abundance of data, so you can make these really great analyses,” said Callahan. “And other sports might not have that.”
The fundamental science at the heart of the study is the relationship between temperature and air density, which affects how fast a ball can travel through the air. When the air is cooler, the air particles are much closer together, which can slow down a fast-moving ball. When the air gets warmer, the air particles are much farther apart, enabling a ball to travel through the air much faster. These basic principles extend far beyond baseball, but the study clarified the relationship between climate and home runs.
Baseball professionals have speculated in the past that climate change could increase home runs, most notably when professional commentator and former player Tim McCarver made the connection in 2012. At the time, he was ridiculed by sports journalists for making that observation, but the study adds more weight to his theory.
The authors controlled for other factors that might have contributed to the overall rise in home runs, including performance-enhancing drugs, player training, and the actual construction of the baseball itself.
“I was pretty surprised, just in the sense that the relationship was so robust,” said Callahan. “Any way you selected any version of the data to use, any time period you look at, you get the same result.”
But an important caveat of the study is that it is difficult to attribute any single home run to climate change, much like climate scientists are wary of saying that a single event is related to climate change.
“I think that the science at the moment does not allow us to tie any particular home run to climate change,” said Callahan.
Nathaniel Dominy, professor of anthropology at Dartmouth College and a co-author, said that more than anything, this study showed climate change’s far-reaching consequences.
Studies about climate change usually focus on the larger groups that will be affected, like people living near the coastline, or the economy. But studies like these ones are important, according to Dominy, because they help demonstrate how climate change will affect every aspect of daily life.
“There are aspects of our daily lives, things that we hold dear, that will be affected by climate change that are beyond the typical talking points,” said Dominy.