Atmospheric nitrogen deposition represents a significant threat to habitats and species in the UK. It leads to nutrient imbalances associated with eutrophication and acidification that result in declines in many of the key species of high conservation value at the expense of a smaller number of fast growing species that can exploit conditions of improved nitrogen supply. These threats result from the emissions of both nitrogen oxides (NOx) to the atmosphere from vehicles, industry and electricity generation, and of ammonia (NH3) to the atmosphere mainly from agricultural sources. Substantial efforts have been placed in UK and European policies over the last years to reduce air pollution emissions, including the use of 3]way catalysts on cars,
and these have substantially reduced NOx emissions. By contrast, so far much less has been achieved in reducing ammonia emissions. In this context, UK ecosystems, and especially priority sites and species designated under the EU Habitats Directive remain under substantial threat. The EU is currently preparing to revise its air quality policy, and in particular the National Emissions Ceilings Directive (NECD). Research is therefore provided by this project to synthesize current knowledge on the available opportunities for reducing NOx and NH3 emissions, and hence reduce both atmospheric concentrations and deposition of these pollutants, providing the conditions to avoid further damage and allow recovery of UK ecosystems.
Key issues being addressed in this contract include: extent of threat and the relationships of priority habitats and species to pollutant distribution; options for pollution mitigation, including both source oriented measures and landscape oriented measures that optimize spatial relationships, cost]benefit analysis to identify the most promising measures; examination of the potential legislative, voluntary and financial instruments that can be used to provide incentives to support nitrogen pollution mitigation, especially in the context of strengthening the UK Green Economy; and an exploration of a selection of case studies that can inform how certain strategy options might be worked out in practice. The project is established on a rapid timescale during 2013 and 2014 to provide scientific evidence, scenario analysis and technical advice in direct support of the revisions of EU air quality policy.
This project will provide evidence to contribute to both air quality and biodiversity policies which are at European, UK and individual UK country level. The project will provide evidence and potential solutions to help meet requirements under the Habitats Directive, Biodiversity 2020 and other UK country biodiversity strategies. It will provide supporting evidence of measures to reduce impacts of atmospheric nitrogen deposition on biodiversity and Annex 1 habitats at the UK and European level, for consideration in negotiations for the revision of the National Emissions Ceiling Directive likely to start in autumn 2013. It will also influence domestic policies for agricultural practices to control nitrogen emissions and consequent deposition. The project will draw together other work by Defra, for example on measures to reduce ammonia emissions and recommendations to the Rural Development Programme discussions.