A quick rejoinder to Ben Zycher on the EPA’s rescission of the endangerment finding.
In Regulation’s Fall 2026 issue, Ben Zycher maintains that my critique of the Environmental Protection Agency’s move to rescind the so-called “endangerment finding”—which originally set in motion the regulation of greenhouse gas emissions from new motor vehicles under the Clean Air Act—is “deeply problematic.” I appreciate that Zycher took the time to engage with my essay, yet I believe his analysis misses the point.
I intend to offer a full response to Zycher in due course. For the moment, I want to call attention to a serious error in Zycher’s attempt at legal analysis.
Zycher writes:
Adler … notes:
Section 111 of the Clean Air Act … only applies to emissions from sources that “cause or contribute significantly” to the air pollution at issue, suggesting the EPA need not—indeed, perhaps, cannot—regulate sources of de minimis contributions under that provision. The absence of any such qualification in Section 202, however, is a mortal blow to the EPA’s position.”
That argument cannot be correct. In the context of Section 202(a), “cause or contribute significantly” is replaced with “reasonably be anticipated to endanger public health or welfare.” Is Adler ignoring this language, or is he actually arguing that GHG emissions yielding temperature effects almost literally equal to zero nonetheless can “reasonably be anticipated to endanger public health or welfare”?
Zycher’s claim here that “in the context of Section 202(a), ’cause or contribute significantly’ is replaced with ‘reasonably be anticipated to endanger public health or welfare'” is simply wrong, as a moment’s review of the relevant statutory text would have demonstrated.
As I noted in my essay, Section 111 requires that the EPA adopt emission standards for a category of stationary sources if that category “causes, or contributes significantly to, air pollution which may reasonably be anticipated to endanger public health or welfare.”
Section 202(a) provides, in relevant part:
The Administrator shall by regulation prescribe . . . standards applicable to the emission of any air pollutant from any class or classes of new motor vehicles . . . which in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare. (Emphasis added.)
“Cause or contribute significantly” in Section 111 is not “replaced with ‘reasonably be anticipated to endanger public health or welfare'” in Section 202, as the “reasonably be anticipated to endanger public health or welfare language” appears in both Section 202 and Section 111, word for word. The relevant difference between the two provisions, as I noted in my essay, is the insertion of the word “significantly,” indicating that a significant contribution is required under Section 111, but not under Section 202.
So, is Zycher ignoring this language or did he not even read it?
Zycher also tries to claim the Section 202 requires the Administrator to find that emissions from new motor vehicles themselves “endanger public health or welfare.” Again he ignores the relevant text. Section 202 requires that the vehicles in question “contribute to” the air pollution that “may reasonably be anticipated to endanger public health or welfare”–not that the emissions from the vehicles themselves endanger public health. Put another way, it is the air pollution to which the vehicle emissions contribute that must be reasonably anticipated to endanger public health or welfare, not the vehicular emissions in isolation. Zycher may think this is irrational or unwise (and I may even agree), but that does not change what the law says.
There is more I could say about Zycher’s reply. For now I’ll simply note that before Zycher suggests someone else is “ignoring” statutory language, he might want to give it a careful read for himself.
