Art by Molly Statt
Yesterday, a House subcommittee voted to strip the Environmental Protection Agency of its power to regulate greenhouse gases, chipping away at a central pillar of the Obama administration’s evolving climate and energy strategy. According to the Environmental Protection Agency’s finding on Dec. 7, 2009:
the current and projected concentrations of the six key well-mixed greenhouse gases — carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) — in the atmosphere threaten the public health and welfare of current and future generations.
I added the italics, to make clear that the EPA was saying that these greenhouse gasses are a threat to the public health. The agency is not hypothesizing that greenhouse gasses cause global warming which causes bad public health. Or is it? Is there a hidden assumption in their science? It might be well be true that a warmer planet is bad for us: What do scientists say? Reporting on House hearings about EPA in The New York Times (March 8, 2011) John Broder wrote that
committee Democrats rounded up five eminent academic climatologists who defended the scientific consensus that the planet is warming and that human activities like the burning of fossil fuels are largely responsible. The professors called for swift and concerted action to reduce emissions of greenhouse gases like carbon dioxide…
while
Republicans countered with two scientific witnesses who said that while there was strong evidence of a rise in global surface temperatures, the reasons were murky and any response could have adverse unintended effects. Another scientist said that the E.P.A.’s decision to ban the pesticide DDT 40 years ago had led to a huge increase in death and disease in the developing world.
“At House E.P.A. Hearing, Both Sides Claim Science” was the Times’ headline, and I guess it’s true. So let’s take seriously the Republican scientist skeptical of the DDT ban. He asks a valid question, one we could answer with evidence: Does the prohibition of certain pesticides help or harm the public health? We would have to consider at least two mechanisms: how does a lack of pesticide affect food production, as well as, how does pesticide cause disease?
What I’m missing in the larger debate here about the EPA, greenhouse gasses and global warming is a mechanism: how does global temperature affect public health?
Paul Statt Communications 