The polar ice caps feel remote. The threat of orioles permanently leaving Baltimore for cooler climates might be a little more compelling. But researchers are learning that the most effective way around climate-policy ambivalence is to invoke imminent dangers to human health. "What's killing me today?" with emphasis on killing and me and today.
For one, when there is more carbon dioxide in the environment, plants produce more pollen, which is no good for allergies and asthma. Rutgers allergist Leonard Bielory recently warned that pollen counts are projected to double by 2040. Likewise, U.S. foresters recently calculated that trees seem to be averting around $6.8 billion in human health costs annually, largely due to mitigating effects of air pollution (even if they do produce pollen). And already the World Health Organization is warning that air pollution is responsible for one out of every eight human deaths, largely because combustion of fossil fuels results in invisible airborne particles that get lodged in our lungs and suspended in our blood.
But is that worth the cost of implementing policies that limit carbon emissions? Some say yes.
Yesterday researchers released findings that say an economy-wide cap on carbon emissions stands to pay for itself about 10 times over in near-term human medical benefits, specifically reductions in costs associated with respiratory diseases, like asthma, and premature death. A standard, economy-wide cap and trade program, the MIT-based research team found, would result in a net benefit of $125 billion in human health costs. The work is published in the journal Nature Climate Change.
“We were looking at ozone and particulate matter, the two biggest air quality issues in the United States,” Tammy Thompson, a research scientist at Colorado State University with the Cooperative Institute for Research in the Environment, told me.
Reasonable people disagree over the economic effects of cap and trade, the politically divisive market-oriented system designed to limit air pollutants with incentives that reward efficiency and innovation. But Thompson, along with Noelle Selin, Sebastian Rausch, and Rebecca Saari at MIT write that any cost-benefit analysis of climate policy that omits the health effects of regional air pollution “greatly underestimate[s] benefits.”
There are national air quality standards that cover ground-level ozone and particulate matter, but this study showed that policies aimed at reducing carbon emissions could improve air quality in amounts comparable to those specifically targeting air pollution. “When you put a constraint on carbon emissions in the economy,” Thompson explained, “with that comes co-benefits, where you’re also reducing nitrogen oxides, sulfur dioxides, and other pollutants that react to form ozone and particulate matter that can cause human health issues.”
As carbon emissions are reduced, so are nitrogen oxide and sulfur dioxide, and therefore ozone and particulate matter. So this research model estimated how the latter would be reduced under various carbon policies. In addition to an economy-wide cap and trade, the researchers also looked at narrower cap-and-trade regulations that would focus on the energy and transportation sectors individually, which are known for human health-associated air pollution.
In June, the Environmental Protection Agency proposed the Clean Power Plan, which the agency claims will prevent 2,700 to 6,600 premature deaths in 2030 alone, as well as 140,000 to 150,000 asthma attacks in children. It imposes carbon emission caps that focus on the electricity sector, a model that Thompson and company found less economically efficient than a broader limit on carbon emissions for the entire economy. Thompson said that’s not a surprise; the more narrow and stringent the policy, the more it costs to implement. “I think economists have been screaming this for decades: Let the market decide.”
“We were really interested in looking at how the health response would change if we targeted these sectors that were known to cause air pollution," Thompson said. "We were surprised to see that the human health benefits did not change very much from scenario to scenario. The cost-benefit ratio was largely driven by the cost of the policy, and the economy-wide policy had fewer economic constraints, so that was the cheapest option.”
Lest this research, which was supported by EPA funding, seem like a clear call for economy-wide cap and trade, Thompson pushed back at my suggestion that she had solved the puzzle.
“To say that is absolutely the way we should be going is beyond this study," she said, almost laughing. "There’s a lot more involved in getting people motivated and getting people to cooperate.”
The air quality co-benefits of climate policy examined in the MIT research don’t even include the health costs of air toxics like mercury, or the social cost of carbon (benefits of climate change in terms of food supply and other ecological boons). And there are other externalities like that discouraging vehicle use may improve health by encouraging walking and bicycling. California Representative Henry Waxman also projects widespread economic prosperity. "People would not be looking at the huge number of unemployed in this country," he recently told Politico. "There’d be enormous investments in alternative fuels and fuel efficiency in ways to make the transition to a low-carbon economy."
Particulate matter can cause cancers as well, but, Thompson explained, “Cancer is more associated with air toxics, which we didn’t look at. There would likely be benefits associated with reductions in air toxics," above and beyond what the study measured. But economy-wide cap and trade legislation died in the Senate in 2009. Until the next attempt at passage, there are always trees to plant. Or as researchers from Johns Hopkins School of Public Health recently suggested as a means of enhancing our kidney's ability to excrete the carcinogenic air toxic benzene, we might all eat more broccoli.
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