Too Many Home Runs? Just Blame Performance-Enhancing Climate Change

This column’s most celebrated alumnus used to make fun of media climate obsessions by routinely blaming global warming for all manner of problems large and small.

But perhaps climate coverage has moved beyond parody.

Now along comes a widely reported study purporting to establish a link between climate change and increased home runs in Major League Baseball. [emphasis, links added]

A study in the Bulletin of the American Meteorological Society reports:

Home runs in baseball—fair balls hit out of the field of play—have risen since 1980, driving strategic shifts in gameplay.

Myriad factors likely account for these trends, with some speculating that global warming has contributed via a reduction in ballpark air density.

Here we use 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.

The idea that warmer, less dense air enables more hits to clear outfield fences is reasonable enough.

But whenever someone talks about home runs rising since 1980 there is the natural question of whether the study authors have adequately accounted for what is commonly known as the game’s steroid era—and when and to what extent that era truly ended.

Some players may have found new ways to avoid testing positive for performance-enhancing substances. Others clearly have not.

As for the period from 2010-2019, which is a major focus of the study, University of Colorado environmental studies professor Roger Pielke Jr. tweets in response that minor leaguers didn’t produce the same increase in home runs:

There is an obvious control group, AAA baseball (completely ignored in this new paper)

And home runs are down in AAA…

Maybe climate change only has effects in the major leagues?

Silly science is still fun!

Mr. Pielke argues that data from Japanese baseball and U.S. college play also don’t show the same rise in homers as in the Major Leagues.

And yet we all share the same planet.

Natalie O’Neill of the New York Post reports on the study and the media reaction:

Sounds like a bit of hot air…

But despite the onslaught of headlines, the effect was small — and could be chalked up to everything from stronger players to “livelier” baseballs.

It’s true that the study authors acknowledged the role of other factors in home run trends but do they understand these other factors well enough to craft their estimate on climate-induced homers?

Mike Axisa of CBS Sports reported last year on Major League Baseball:

Suffice it to say, MLB’s recent history is rife with inconsistency when it comes to the properties of the actual, physical baseball itself. This has resulted in a great deal of unpredictability from year to year, especially when it comes to home run rates.

A rise in home runs in 2019 inspired the major leagues to study the surge. Mr. Axisa reports:

Specifically, the committee found that roughly 40 percent of the increase in power was due to a widespread “change in player behavior,” which refers to increasing emphasis of hitters on achieving a launch angle off the bat that’s ideal for power production. The rest, they posited, was due to seam height.

That, however, was not the final word. Astrophysicist Dr. Meredith Wills, who has emerged as the leading independent authority on the state of the baseball, conducted her own examination of the 2019 baseball relative to earlier models and presented her findings in a June 2019 piece for The Athletic.

She hypothesized that Rawlings, starting with the 2019 batch, began machine drying the baseballs whereas before they allowed baseballs to air dry. That, in turn, perhaps allowed Rawlings to better meet MLB’s increased demand for baseballs (Triple-A used MLB baseballs in 2019, and, just as in MLB, home run rates vaulted). The physical changes she found in the baseballs starting in 2019 are consistent with what would happen if you applied heat to a baseball to speed up the drying process.

Can anything be done to slow the publishing process of reporters eager to make every story a climate story?

Read full post at WSJ