If carbon dioxide is a pollutant, then ‘We’re all polluting,’ Justice Alito says

If carbon dioxide is a “pollutant,” then breathing is bad for the environment, U.S. Supreme Court Justice Samuel Alito said last Saturday during his keynote address at the Claremont Institute’s 2017 annual dinner honoring Winston Churchill.

“All of us are exhaling carbon dioxide right now,” Alito said. “So if it’s a pollutant, we’re all polluting.”

utah transit

Alito was referring to a 2007 court decision (Massachusetts v. EPA) finding that carbon dioxide is a pollutant subject to EPA regulation under the Clean Air Act.

The Clean Air Act defines “air pollutant” as “any air pollution agent or combination of such agents, including any physical [or] chemical . . . substance or matter which is emitted into or otherwise enters the ambient air” and “may reasonably be anticipated to endanger public health or welfare.”

The court ruled 5-4 (with Alito dissenting) that carbon dioxide emissions from new motor vehicles fall within that definition.

Ten years later, Alito still disagrees.

Justice Alito

“Now, what is a pollutant? A pollutant is a subject that is harmful to human beings or to animals or to plants. Carbon dioxide is not a pollutant. Carbon dioxide is not harmful to ordinary things, to human beings, or to animals, or to plants. It’s actually needed for plant growth. All of us are exhaling carbon dioxide right now. So, if it’s a pollutant, we’re all polluting.”

It’s true that humans breathe in oxygen and breathe out carbon dioxide. But according to the McGill Office for Science and Society, “every atom of carbon in the exhaled carbon dioxide comes from food that was recently produced by photosynthesis.”

pretty plants

In other words, humans don’t produce new carbon dioxide. “Since all the carbon dioxide we exhale originated in carbon dioxide captured by plants during photosynthesis, we are not disturbing the carbon dioxide content of the atmosphere by breathing.”

Motor vehicles, on the other hand, don’t eat plants. So the carbon dioxide that they emit can’t easily be compared to the carbon dioxide exhaled by humans.

By Rebecca Wilhelm