EPA’s proposed endangerment finding asserts that greenhouse gas emissions from US mobile sources cause or contribute to public health harm. However, the Clean Air Act distinguishes between “public health” and “welfare.” EPA proposes to count some welfare-related effects as public health effects.
EPA is relying on the authority provided by Section 202(a)(1) of the Clean Air Act:
The Administrator shall by regulation prescribe (and from time to time revise) in accordance with the provisions of this section, standards applicable to the emission of any air pollutant from any class or classes of new motor vehicles or new motor vehicle engines, which in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare.
Historically, EPA has regulated air pollutants on public health grounds because of health effects that are the consequences of pollutant inhalation. Effects that arise through other means have been treated as “welfare” effects. In the proposed rule, EPA acknowledges that there are no adverse health effects from greenhouse gases:
To be clear, ambient concentrations of carbon dioxide and the other greenhouse gases, whether at current levels or at projected ambient levels under scenarios of high emissions growth over time, do not cause direct adverse health effects such as respiratory or toxic effects (p. 18901).
Thus, any public health effects that might arise from greenhouse gas emissions are mediated through a series of welfare effects beginning with climate change and proceeding through a series of complex pathways:
All public health risks and impacts described here as a result of elevated atmospheric concentrations of greenhouse gases occur via climate change. The pathway or mechanism occurs through changes in climate, but the end result is an adverse effect on the health of the population. Thus these effects from climate change are appropriately denoted public health effects. It is important to acknowledge that effects on “welfare” do not always entail effects on “public health,” and the Administrator does not mean to interpret “public health” to include “welfare” effects as such. Today’s interpretation does not collapse the two categories—many “welfare” effects do not and cannot involve public health. The Administrator simply means to recognize, with the scientific community, that concentrations of greenhouse gases endanger public health through a wide range of pathways (Id.).
Notwithstanding EPA’s protestation that the proposal “does not collapse the two categories,” it appears to do something at least very similar to collapsing them: muddying the difference between them.
Why EPA wants to move welfare effects into the public health category is not clear from the proposal. Nonetheless, the text makes very clear that this is exactly what the Agency intends to do:
Some have argued that a positive endangerment finding for public health cannot be made because the health effects associated with elevated atmospheric concentrations of greenhouse gases occur via climate change, and not directly through inhalation or other exposure to the greenhouse gases themselves. These commenters argue that because ‘‘climate’’ is included in the definition of welfare, the Act requires that all effects which may flow from a welfare effect must themselves be considered a welfare effect. The Administrator disagrees with this narrow view of the endangerment criteria. Mortality and morbidity that result from the effects of climate change are clearly public health problems. It would be anomalous to argue that a person who is injured or dies from heat exhaustion or increased exposure to a pathogen has not suffered a health impact. In addition, tropospheric ozone is already regulated under the Act as a criteria air pollutant in part due to its adverse impacts on public health. It is estimated that climate change can exacerbate tropospheric ozone levels in some parts of the U.S. The Administrator rejects a position that would treat the adverse effects on the health of individuals caused by tropospheric ozone as something other than a public health threat because they are exacerbated by climate change (p. 18902).
The final sentence suggests that EPA is appealing more to emotion than to the law. That is, it appears that EPA believes “mere” welfare effects do not seem to be important enough to justify the scope, scale, and economic effects of the regulations that the Agency expects to promulgate subsequent to finalizing this proposed rule.