Climate change linked to record-breaking home runs in MLB, says new study

Eddie Rosario #8 of the Atlanta Braves hits a solo home run during the eighth inning against the Cincinnati Reds at Truist Park on April 12, 2023 in Atlanta, Georgia. (Photo by Todd Kirkland/Getty Images)

Major-league sluggers are hitting home runs at record rates, but a new study links part of that power surge to climate change. Warmer temperatures mean more baseballs flying into the stands at Major League Baseball games around the nation.

Ballpark dimensions, better hitting technique and performance-enhancing drugs could play a part. But according to new a new study in the Bulletin of the American Meteorological Society our warming climate is juicing the flight-path of baseballs.

"There has been a homerun surge over the last 10 years or so," said Christopher Callahan, a Ph.D. candidate in climate science at Dartmouth College in New Hampshire and the study’s lead author.

Callahan says less air drag means hundreds more hits are sailing into the stands around Major League Baseball.

"We know that when the air is warmer it’s less dense, meaning there is less air resistance for a ball to travel through when it’s hit," Callahan said. "By increasing temperatures and reducing the density of air during ball games climate change has to some degree increased the likelihood of home runs

"We attribute about 500 total home runs over the last 10 years to climate change. That’s only about 1-percent of all home runs hit in MLB, so it’s certainly not the only thing going one, but it is a factor." 

John Knox, a geography professor at the University of Georgia, was skeptical at first. "When I first saw the headline I thought you got to be kidding." Then he read the study. "They did a careful analysis. I am a convert after having looked at the paper." 

He says 1-percent may not seem like a lot, but it is noteworthy. "It actually is a statistically significant increase. It’s about 50 home runs a year," Callahan said.

Callahan says rising temperatures could account 10-percent of home runs by the end of the century. "Climate change will give us more home runs," he said. 

Callahan says hitters would still be knocking homers out of the park at high rates even without global warming. He says climate change just made the homerun derby even more intense. 

Callahan says the league and teams could take action to avoid climate change intensifying home runs. "This might be changes to the construction of the baseball, moving day games to night games, so they’re in milder temperatures and putting domes over ballparks to insulate them from ambient temperatures." 

Callahan says, more importantly, we could reduce green-house emissions to blunt the effects of global warming.