Nitrous oxide under the international ozone regime: A new governance pathway for a growing threat

A 1.5 °C world and healthy stratospheric ozone layer is impossible to achieve without ambitious action to reduce nitrous oxide (N 2 O) emissions. While N 2 O is currently controlled under the international climate regime, only a handful of countries have committed to reduction targets. We argue that the international community should consider controlling N 2 O under the Montreal Protocol, the international ozone agreement. The Montreal Protocol is widely considered the most successful international environmental agreement ever. The Protocol’s focus on production and consumption is well suited to nitrogen pollution, and it has a successful track record in the agricultural sector—N 2 O’s dominant source. A special report from the Protocol’s assessment panels could provide the scientific foundation for action, and an initial focus on industrial N 2 O could be a springboard to address additional sectors. In short, the international ozone agreement creates a unique opportunity for action on a multifaceted threat that we can no longer ignore.