Valuing Improvements in Biodiversity Due to Controls on Atmospheric Nitrogen Pollution.

Atmospheric nitrogen pollution has severe impacts on biodiversity, but approaches to value them are limited. This paper develops a spatially explicit methodology to value the benefits from improvements in biodiversity resulting from current policy initiatives to reduce nitrogen emissions. Using the UK as a case study, we quantify nitrogen impacts on plant diversity in four habitats: heathland, acid grassland, dunes and bogs, at fine spatial resolution. Focusing on non-use values for biodiversity we apply value-transfer based on household's willingness to pay to avoid changes in plant species richness, and calculate the benefit of projected emission declines of 37% for nitrogen dioxide (NO 2 ) and 6% for ammonia (NH 3 ) over the scenario period 2007–2020. The annualised benefit resulting from these pollutant declines is £32.7 m (£4.4 m to £109.7 m, 95% Confidence Interval), with the greatest benefit accruing from heathland and acid grassland due to their large area. We also calculate damage costs per unit of NO 2 and NH 3 emitted, to quantify some of the environmental impacts of air pollution for use alongside damage costs for human health in policy appraisal. The benefit is £103 (£33 to £237) per tonne of NO 2 saved, and £414 (£139 to £1022) per tonne of NH 3 saved. [ABSTRACT FROM AUTHOR]