The social cost of nitrous oxide is understated under current estimates, new analysis concludes

The social cost of nitrous oxide, a greenhouse gas that is the largest remaining threat to the ozone layer, is understated, concludes an international team of researchers. In their assessment, which appears in the journal Nature Climate Change, the authors write that improving the accuracy of these calculations would not only give a more accurate picture of the impact of climate change, but also spur nations to more aggressively address it.

The researchers calculate that adding nitrous oxide’s effect on the ozone layer would increase the current social cost of this gas by 20 percent. The effects on ozone-depletion create more severe impacts on human health as well as plant and animal life due to more harmful ultraviolet radiation reaching the Earth’s surface.

“Updating the social cost of nitrous oxide’s impacts to include stratospheric ozone raises the calculation significantly above current estimates,” says David Kanter, an associate professor in New York University’s Department of Environmental Studies and one of the authors.

A revised measurement, the researchers say, would likely affect governmental activity.

“A more accurate estimate would make the case for action on nitrous oxide even more compelling and increase the likelihood of meeting U.S. climate and sustainable development goals,” adds author Peter Groffman, a professor with the Environmental Science Initiative at the Advanced Science Research Center at the CUNY Graduate Center.

The Comment article, which also included researchers from Canada’s University of Guelph, the University of California at Davis, PBL Netherlands Environmental Assessment Agency, and NYU’s Wagner Graduate School of Public Service, among other institutions, centers on the social cost of nitrous oxide—an estimate of the economic costs of emissions that provides an assessment of predicted damage caused by resulting climate change.

The current social cost estimates do not take into account how nitrous oxide, or N₂O, affects the ozone layer, which protects earth from the sun’s powerful rays—a crucial omission because its continued depletion could adversely affect crops and marine life while also intensifying human exposure to cancer-causing ultraviolet radiation. Among the largest sources of N₂O emissions are from nitrogen fertilizers used in agriculture.

“These damage costs are crucial to evaluating the global benefits and costs of policy measures to address climate change and are used in several countries beyond the U.S., including Canada and the United Kingdom,” the authors write. “Scientists and economists have invested heavily in improving estimates of the social cost of carbon. However, the social cost of nitrous oxide has been given much less attention.”

“Accounting for these impacts in regulatory review—as well as how they are distributed across and disproportionately affect vulnerable and marginalized communities—could significantly influence the types of policies that are favored,” they conclude.