Main Objective of this COST Action

The main objective of the COST 729 project is to advance the understanding and quantification of atmosphere-biosphere nitrogen fluxes in Europe in relation to the main economic sectors, interactions with the natural environment and current policies, in order to establish a sound scientific basis for strategies to reduce the environmental impacts of nitrogen.

Scope of this COST Action

The Action aims at combining the knowledge from various research areas throughout Europe in order to provide a scientific base for an integrated approach to nitrogen management with a focus on the atmosphere – biosphere interactions. Basically, this requires knowledge on:

• The formation of reactive nitrogen and the resulting emissions to the atmosphere. Currently emissions are estimated through EMEP and EEA under the CLRTAP and FCCC. However, there is particular uncertainty about the indirect emissions of N₂O. Furthermore, the research on ammonia emissions has shown that there is a huge uncertainty in NH₃ and NO_x emissions from diffuse sources and its spatial and temporal variations. Also the spatial resolution of emissions estimates is an important factor to be considered, as most effects occur close to sources or source areas, and current estimates are frequently of limited resolution.
• Transport , transformation and deposition. Current knowledge and modelling about atmospheric transport and transformation is reasonably well covered for the regional scale by EMEP. Although the new EMEP model is considered suitable for policy support, further attention needs to be given to spatial resolution and nesting approaches. Key new developments, especially in relation to nitrogen, should be the modelling of feedbacks, e.g. through climate change, the interactions with both the local and global scales and the cascade effect of nitrogen. A major focus should be on the modelling of chemical and biological interactions and feedbacks in the atmosphere – biosphere system, including terrestrial and marine areas.
• Integrated Assessment Modelling. The RAINS model of IIASA has been well developed over the years and forms a key tool in supporting international negotiations for acidification effects. Nitrogen and eutrophication has, however, not been a main focus. Source – receptor matrixes are used that are not suitable to address the complex nature of nitrogen. Furthermore, the local scale emissions and effects close to sources and source areas cannot be taken into account. Finally, the feedback mechanisms and the relation with climate change are not well addressed.
• Policy analysis and support. Based on the synthesis of information in each of the above areas, there are important opportunities to link the transboundary atmospheric pollution and greenhouse gas strategies for nitrogen control. The synergies need to be developed and presented in a clear way to the relevant international conventions and national parties to allow more coherent responses to excess nitrogen to be developed.

The Action will not develop new databases or modelling tools, where current tools fulfil the needs within the required accuracy and scales. The Action will therefore focus on the new items as described in the scientific descriptions. The collaboration between research groups from different parts of Europe, as established within the COST-framework, will ensure the development of a holistic approach. Atmospheric processes and pathways are highly important in the nitrogen cycle. Since these cannot be tackled directly through management practices, there is a need to identify processes in various economic sectors that can be most effectively targeted in order to reduce various nitrogen emissions. When considering the impacts, the interaction between the atmosphere and the biosphere is important. The Action will focus on defining common indicators for assessing the effectiveness of various policies, both in terms of nitrogen efficiency and in terms of socio-economic and environmental sustainability.

The disturbance of the nitrogen cycle on the different scales is much broader than the atmosphere–biosphere interactions of terrestrial and marine systems. However, the knowledge of the whole nitrogen cycle is far from complete and this provides the appropriate starting point for developing the processes of fully integrated assessment. Therefore, this Action is restricted to the atmosphere – biosphere interaction. While this provides the necessary focus, there will however be room within the Action to explore the other interacting parts of the nitrogen cycle (e.g. with water quality) to start the process of developing an integrated assessment of the whole nitrogen cycle.

The breadth and ambition of this COST Action will require collaboration between research groups from different parts of Europe, and across different disciplines but where atmospheric scientists will have a central place. The COST-framework thus is very suitable for such an endeavour, due to its flexibility and ability to accommodate various groups and expertise in an effective manner. This will ensure the development of a holistic approach.

The programme has started mid 2005 and will run for five years.