I was extremely disappointed to see Steve Sherwood’s article comparing resistance to heliocentrism half a millennium ago with modern resistance to the idea that dire consequences will result if urgent action is not taken soon to reduce carbon dioxide emissions. How can those ideas even be put on the same footing? The first is a physical theory whose validity poses a single, clear question, while the second involves a large set of issues, some scientific, some economic, some technological, and some political, with answers that are not yes or no but involve matters of degree and prudential judgment.

There are legitimate questions about how much recent warming is due to CO2, how much warming will occur in the future, how harmful it will be, how effective different mitigation strategies will be, how reasonable it is to expect action from enough of the world to make a difference, and what the cost–benefit calculation will be. Sherwood’s psychological judo maneuver of comparing those pushing back against demands for immediate drastic action against CO2 emissions with those who resisted heliocentrism delegitimizes any push-back efforts. The following portion of Sherwood’s article ought to have been a clear tip-off that the intent was not to further scientific understanding and communication but to shut it off:

Many who are unwilling to accept the full brunt of greenhouse warming have embraced a more comforting compromise reminiscent of the Tychonic system: that CO2 has some role in climate but its importance is being exaggerated. But accepting a nonzero warming effect puts one on a slippery slope: Once acknowledged, the effect must be quantified, and every legitimate method for doing so yields a significant magnitude. As the evidence sinks in, we can expect a continued, if slow, drift to full acceptance.

Excuse me, but what the heck can that mean? What does “full acceptance” mean? That we must cut CO2 production to zero tomorrow? Anything less can be construed as less than “full acceptance.” And what does “significant magnitude” of warming mean? Must every warning of even worse warming or worse consequences be accepted or else one is guilty of standing on the “slippery slope”?

I have respected PHYSICS TODAY for its previous excellent historical pieces. It is therefore a shock to see such a blatantly political article published in the magazine.