Why Metrics Matter: Evaluating Policy Choices for Reactive Nitrogen in the Chesapeake Bay Watershed

Abstract

Despite major efforts, the reduction of reactive nitrogen (Nr) using traditional metrics and policy tools for the Chesapeake Bay has slowed in recent years. In this article, we apply the concept of the Nitrogen Cascade to the chemically dynamic nature and multiple sources of Nr to examine the temporal and spatial movement of different forms of Nr through multiple ecosystems and media. We also demonstrate the benefit of using more than the traditional mass fluxes to set criteria for action. The use of multiple metrics provides additional information about where the most effective intervention point might be. Utilizing damage costs or mortality metrics demonstrates that even though the mass fluxes to the atmosphere are lower than direct releases to terrestrial and aquatic ecosystems, total damage costs to all ecosystems and health are higher because of the cascade of Nr and the associated damages, and because they exact a higher human health cost. Abatement costs for reducing Nr releases into the air are also lower. These findings have major implications for the use of multiple metrics and the additional benefits of expanding the scope of concern beyond the Bay itself and support improved coordination between the Clean Air and Clean Water Acts while restoring the Chesapeake Bay.

How cost-effective are cover crops, wetlands, and two-stage ditches for nitrogen removal in the Mississippi River Basin?

“…These nutrient reduction strategies incur large economic costs, as do the consequences of N pollution [12][13][14]. As a result, several studies have examined how to mitigate N pollution, while minimizing costs.…”

A post-Kyoto partner: Considering the stratospheric ozone regime as a tool to manage nitrous oxide

“…Ideally, it is at the point of Nr formation (e.g., the Haber-Bosch process). It can also be where cost minimization and optimal environmental protection coincide (e.g., precluding future healthcare costs caused by air pollution) (59,60). Formulating N 2 O controls for the agriculture sector around the concept of fertilizer efficiency (i.e., better synchronizing soil N supply with crop N demand) could take this aspect of the N cycle into account, not only complementing the ozone regime's historical focus on controlling production and consumption (Legal Authority of the Ozone Regime, Legal Authority to Regulate N 2 O) but also providing a potentially effective way to prevent a damaging N cascade.…”

Novel decision model for delivering sustainable infrastructure solutions – an Australian case study

“…potential future costs associated with external impacts such as damages to environmental and human health, Type V costs). LCA is a growing research field and there are now many studies that have attempted cost-benefit assessments of a range of infrastructure initiatives at a large scale, including monetisation of nutrient emissions [29][30][31]. The SIDM © externality assessment is tailored to the context of scale (local or regional infrastructure schemes), the existing regulatory framework, and to the actual costs of environmental degradation borne by external groups over and above regulatory compliance activities, in response to community expectations.…”

“…Although costs of nutrient loss did not represent a major component of the overall costs, both alternative options performed much better than the Base Case for this externality given they incorporated reuse of treated effluent for irrigation. Note, other costs commonly considered in the analysis of nutrient emissions [29][30][31], were not included in this study since this was a local infrastructure project and regional assessment of impacts not relevant to the scale. In terms of other externalities related to impacts from system failure, the results indicated that the offsets required for these Type 5 costs for the Base Case were more than five times that of Option 2 ( Table 2).…”