Green economy thinking and the control of nitrous oxide emissions

As a potent greenhouse gas and contributor to stratospheric ozone depletion, nitrous oxide (N2O) represents a global pollutant of growing concern. We use the N2O example to consider the potential for Green Economy thinking to promote sustainability through emission reduction. A fundamental barrier to change arises from the distinction between ‘Sector View’ (green actions consistent with improved profit) and ‘Societal View’ (incorporating the value of all externalities). Bringing these views closer together requires a long-term perspective, while counting all co-benefits of taking action. N2O control should be considered within the context of the wider nitrogen cycle, with an emphasis on improving full-chain nitrogen use efficiency (NUEfc), exploiting a combination of technical measures in agriculture, industry, transport, waste water management and other combustion sources. Avoiding excessive meat and dairy consumption by citizens in developed countries can substantially reduce N2O emissions. These measures offer many options for low-cost control of N2O emissions, while reducing the health and ecosystem threats of other N pollution forms. In order to bring the ‘nitrogen green economy’ forward, a much stronger public profile is needed to motivate citizens' actions and to encourage investment in bringing new technologies to profitability. A recent estimate suggests that improving global NUEfc by 20% would provide a N-saving worth ~23 billion USD to business, plus health and environmental benefits worth ~160 billion USD. The value of externalities highlights the green economy case for governments to develop a suite of instruments to go further in controlling N2O emissions than the Sector View would typically allow.