Climate change adds to baseball's offensive boom as warmer air means about 50 more home runs per season, new study finds

• Major League Baseball has seen an uptick in home runs in the past decade.
• Players and analysts have long observed that the ball travels farther in warmer weather.
• A new study from researchers at Dartmouth found at least 500 home runs since 2010 likely caused by climate change.

While climate change has negative effects on the environment, it may be adding excitement to America's pastime, with warmer temperatures leading to about 50 additional home runs per season in the last several years, according to a new study.

A study published Friday in the Bulletin of the American Meteorological Society analyzed data from 100,000 Major League Baseball games and 220,000 batted balls. It attributed at least 500 home runs since the 2010 season to warmer temperatures.

Baseball has long been influenced by the environment. Baseballs famously have flown out of Coors Field, home of the Colorado Rockies, with ease due to the thinner air at high altitudes. 

The study from researchers at Dartmouth College offers the newest examples of how global warming could affect recreation nationwide in the future.

The researchers found that because temperatures are on average higher now than decades ago, the air is warmer more often and therefore thinner during baseball games. Baseballs then face less resistance while flying through the air, making it easier for them to travel farther.

MLB has seen a spike in home runs in recent years, enough that the league controversially used multiple different types of baseballs in one season to dampen the offense, at times without informing the public or players until it was reported by Insider and other outlets.

The Dartmouth researchers acknowledge that the climate change factor is likely minor, as MLB teams hit 5,215 home runs last season, meaning the warmer temperatures only account for about 1% of the long balls. Different baseballs, faster pitches, stronger batters, and generally altered strategy with an emphasis on certain metrics like launch angle have a greater influence on home runs than climate change, the researchers said.

However, the researchers also said climate change could have a larger effect in the future, estimating 192 additional home runs per season by 2050, and an estimated 467 by 2100 in worst-case warming scenarios.

The Dartmouth study, and another commissioned by MLB in 2018, found that the number of home runs per game increases by about 2% per 1 degree Celsius the temperature increases.

If MLB wants to reverse or mitigate the trend, researchers found that games played in a domed, climate-controlled stadium saw only very small effects from temperature. Eight MLB teams currently play in stadiums that feature a permanent or retractable roof.