Waste of Time: Scientists Now Claiming Climate Change Is Affecting Major League Baseball

How do you get Greta Thunberg interested in Major League Baseball? It sounds like the setup to a joke -- and it is, albeit not quite in the way one might intend it to be.

According to a new study from several Dartmouth College academics, global warming has affected how the national pastime is played, helping lead to a surge in the number of home runs.

"Our results highlight the myriad ways that a warmer planet will restructure our lives, livelihoods, and recreation, some quantifiable and easily adapted to, as shown here, many others, not," the authors said in the study abstract, which correlates higher temperatures with higher home-run rates. (Causation, of course, remains elusive.)

The study , released Friday in the Bulletin of the American Meteorological Society, relies on "observations from 100,000 Major League Baseball games and 220,000 individual batted balls to show that higher temperatures substantially increase home runs."

"We isolate human-caused warming with climate models, finding that >500 home runs since 2010 are attributable to historical warming," it says. "Several hundred additional home runs per season are projected due to future warming."

The theory is simple: Cold air is denser, hot air less so. Balls travel further in less dense air. Hence, a spike in home runs seen between 2010 and 2019 could potentially be linked to climate change, the study's authors said.

And it's not just that: "Higher temperatures may affect home runs through multiple complex pathways beyond air density, such as heat stress on pitchers," the study said.

"In some ways this wasn't all that surprising," said Dartmouth doctoral student Christopher Callahan, according to NBC News . Callahan authored the paper with three other professors at the Ivy League School.

“It was relatively straightforward," Callahan said. "In some ways it was confirming that basic physical understanding that we already had."

By 2050, the study's authors claim, climate change will result in 192 more homers a year, and there will be 467 additional homers by 2100.

The parks most affected -- assuming new parks with retractable roofs and different dimensions aren't built, of course -- will be the Chicago Cubs' Wrigley Field, the Detroit Tigers' Comerica Park and the Minnesota Twins' Target Field.

“Places like Wrigley Field will see a lot more home runs in the future, because it’s open air and a lot of games are played in the daytime,” Callahan said.

“And so you get a ton of more [climate-affected] home runs there, but you’ll get a lot fewer in places where there are domes and the games are more frequently played in the evening to start with," he said.

Now, beyond the big fat waste of time and resources this represents, there are several major issues with pinning the spike in home runs on climate change .

The first is that the paper doesn't mention any possible shifts in strategy that may have caused this phenomenon. For instance, between 2010 and 2019, we saw an increase in what became known as the " defensive shift ," something MLB limited in new rules introduced this season.

Essentially, the defensive shift takes fielders and, instead of putting them where they would typically be positioned, clusters them around where individual hitters are statistically most likely to hit the ball, according to analytics.

There's one good way to foil the defensive shift -- which is to hit the ball out of the park, where fielders obviously can't be shifted. The paper, however, mentions this phenomenon and its increased usage over the time period in question not once, and it's unclear whether the authors ever considered it.

Nor did anyone consider that baseball in the 21st century has become, um, a human chemistry experiment. Sure, the days of Mark McGwire and Barry Bonds having bovine levels of steroids coursing through their bloodstreams is over, but testing for other performance-enhancing drugs such as human growth hormone is notoriously difficult , and not every cheater is going to be caught.

The idea that trying to hit more long balls at the expense of the single, double or triple is borne out by falling batting averages since the turn of the century. According to Baseball Reference , the MLB batting average in 2010 was .257, and it dropped to .252 in 2019, the last year covered in the study. (It fell as low as .248 in 2018, it's worth noting.) Meanwhile, in 2000, it was .270.

As economist Thomas Sowell noted in his groundbreaking look at the difference between the "dead ball" era of the sport prior to 1920, where very few home runs were hit, and the "live ball" era inaugurated by players like Babe Ruth, batting average goes down as hitting for the fences goes up.

Moreover, several sources have looked into this and come to different conclusions -- including Major League Baseball, which conducted its own study.

In 2018, stat geek outlet FiveThirtyEight did a close examination of the balls used in MLB , manufactured by sporting goods company Rawlings, and said, "Looking inside the balls and testing their chemical composition revealed that the cores of recent balls were somewhat less dense than the cores of balls used before the 2015 All-Star Game."

"The newer cores weigh about a half a gram less than the older ones, which might be enough to cause baseballs hit on a typical home run trajectory to fly about 6 inches farther," it said.

"That alone is hardly enough to explain the home run surge of recent seasons, but when combined with previous research finding that baseballs began to change in other small ways starting around the same time, it suggests that a number of minor differences may have combined to contribute to the remarkable upswing in home run power we’ve witnessed since 2015."

Major League Baseball's commission of scientists and statisticians countered FiveThirtyEight's findings about the core of the ball but found another factor that could be causing it: an unexplained reduction in the drag coefficient of the baseball since 2015.

"After studying batted ball data generated by Statcast, the committee concluded that, in the 2016 and 2017 seasons, there was not a substantial change in the percentage of batted balls that fell within the right ranges of exit velocity and launch angle to create a home run, but there was a substantial change in the rate of home runs themselves," MLB said in its summary of the report.

"Though the study did not discover meaningful changes in the ball's lift, it found that the drag coefficient of MLB balls has decreased since 2015," the summary said. "The researchers used a physics model to calculate that if the change in home run rate was attributable entirely to changes in drag, one would expect the drag coefficient to have decreased by approximately 0.012. The exact change in drag coefficient in the time period studied -- if you're scoring at home -- was 0.0153."

This could be attributable to more precise manufacturing techniques resulting in more uniform balls, although that couldn't be proved.

One thing it ruled out, however? Climate change .

"It is well-known that higher temperatures result in lower air density, reduced drag and, ergo, better carry," the summary read. "Though global climate change is very much measurable, it has not had a dramatic effect on batted baseballs in the time period in question.

"The committee's research found that the differences in home run rate persist even at fixed temperature values for both open-air and domed stadiums."

The Dartmouth study contested this, finding that "domed parks experience only 45% of the home run increase that non-domed parks do" -- while still acknowledging that yes, there was an increase in home runs at domed parks. Never mind that this could correlate to teams in domed stadiums oft not being among the MLB's finest (Arizona Diamondbacks, Miami Marlins, Seattle Mariners).

Furthermore, as the New York Post reported, a University of Colorado professor noted that while MLB home runs were up over that period, home runs in the top minor leagues were down .

"Maybe climate change only has effects in the major leagues?" professor Roger Pielke Jr. joked. There is an obvious control group, AAA baseball (completely ignored in this new paper)

And home runs are down in AAA https://t.co/zWzneW28fg

Maybe climate change only has effects in the major leagues?

Silly science is still fun! pic.twitter.com/Kkz136G1RF

— The Honest Broker by Roger Pielke Jr. (@RogerPielkeJr) April 7, 2023

Again, this study still leaves more questions than it answers, the key question being: Why does it even exist?

Resources were used for this. Four men devoted some of their time to putting this together and putting their names on it.

Yes, I know: Publish or perish. Also, the fact everyone is writing about this seems to confer unearned importance upon it; by the act of dragging out contradictory facts about MLB home runs the paper doesn't address, I've already implied it's worth parrying about. It's not.

Assume anthropogenic climate change is going on the trajectory these scientists believe it is. Fine. Dome all stadiums. Or change the rules. Raise the pitcher's mound. Set minimum dimensions for parks. Come up with an effective test for the more effective ways athletes use to circumvent anti-doping measures. Or just enjoy the fact there are more home runs, which is kind of cool. Who cares?

All this does is give Greta's acolytes a few minutes to rub alarmism in the noses of what they doubtlessly perceive as atavistic troglodytes. See, you hot-dog-scarfing jocks? Your precious baseball and its myriad traditions will be ruined! Ruined? What say you now, Cletus?

And here's where I and other Cletuses across America shrug, say, "Whatever," propose some more rule changes and move on with our lives.

Meanwhile, I think a few Dartmouth donors who are high-earning Cletuses might have something to say to their alma mater about how their money is being spent.

This article appeared originally on The Western Journal .