The CCE collaborates with National Focal Centres (NFCs) to support effect-based, integrated assessment of European air pollution abatement policy alternatives. NFCs are institutes that are responsible for producing the national data on critical loads/levels and maps for inclusion in the European maps in accordance with the Mapping Manual guidelines. The particular responsibilities of the NFCs are:
- collection and archiving of data needed to obtain maps in accordance with the Manual guidelines and in collaboration with the CCE,
- communication of national mapping procedures (data, formats, models, maps) to the CCE,
- provision of written reports on the methods and models used to obtain national maps,
- organisation of training measures for national experts in collaboration with the CCE,
- making the necessary provisions to obtain national maps in accordance with the resolution and standards (measurement units, periodicity, etc.) described in the Manual,
- collaborating with the CCE to permit assessment of the methods applied in order to perform multinational mapping exercises (e.g. using GIS) and model comparisons,
- updating the mapping manual as appropriate, in collaboration with the Task Force on Mapping and the CCE.
The National Focal Centres (NFC) of the International Cooperative Program of Modelling and Mapping (ICP M&M) are regularly invited by the Working Group on Effects (WGE) to update their national Critical Loads (CL) data. This procedure is formalised in a so-called "Call for data" (CfD). The use of national data has at least two particularly positive aspects. The first is the potentially higher level of detail of the input data which is used by the NFC for the modelling of national CL data. This better spatial accuracy in national data compared to European-wide maps modelled from the EU-DB is particularly relevant for risk assessment of rare ecosystem types, since scarce ecosystems are usually not well presented in datasets covering relatively large areas (e.g. whole of Europe). The second important advantage is the inclusion of national decisions related to the CL derivation itself. The results of CL modelling exercises are very sensitive to the choice of receptors and also to the choice of either the upper or lower boundary of CL. In other words, the choice of what to protect and what impacts to avoid is crucial and should, in the best case, be made by the countries themselves. Only 14 of 50 parties to the Convention responded to the last CfD (2019-2021). The CL data submitted by NFCs covers about 45% of the total area of the whole dataset for Acidification, and about 40% for Eutrophication respectively.
In 2024 the recent data from the CfD 2023 will be integrated by CCE in the European map for Critical Loads based on the latest receptor data available. This map will be provided to the LRTAP Convention for further application to assess air pollution effects on sensitive ecosystems.
