Despite N₂O’s status as the third most important anthropogenic greenhouse gas and the leading ozone-depleting substance currently emitted, international policy frameworks addressing N₂O remain fragmented, inconsistent, and — by most expert assessments — wholly inadequate to the scale of the challenge. Analyzing why this policy gap exists illuminates both the political economy of climate negotiation and the practical challenges of regulating diffuse agricultural emissions.
The Montreal Protocol Gap
The Montreal Protocol, which successfully controlled chlorofluorocarbons and halons, does not cover N₂O despite N₂O’s ozone-depleting properties. This exclusion reflects the historical sequence: N₂O’s ozone-depleting role was not fully understood when the Protocol was negotiated in 1987, and the predominantly agricultural sources of N₂O make regulation politically contentious in ways that industrial refrigerant controls were not.
UNFCCC Framework Limitations
Under the United Nations Framework Convention on Climate Change and the Paris Agreement, N₂O is included in national GHG inventories and theoretically subject to each nation’s Nationally Determined Contribution (NDC). In practice, however, the agricultural sectors that dominate N₂O emissions are often carved out of NDC commitments, given food security concerns and the practical difficulty of monitoring and verifying diffuse agricultural emissions.
Emerging Policy Approaches
A small number of jurisdictions are pioneering more direct N₂O policy. The European Union’s Farm-to-Fork Strategy includes nitrogen efficiency targets that will implicitly reduce N₂O emissions. New Zealand has proposed including agricultural emissions — including N₂O — in its Emissions Trading Scheme. These examples point toward what a more comprehensive policy framework could achieve, even as global action remains elusive.