Calculation and Mapping of Critical Thresholds in Europe
The fourth report on the Coordination Center for Effects (CCE) describes critical threshold methodologies and results which are used for the scientific support of the second nitrogen oxide protocol under the Convention on Long Range Transboundary Air Pollution of the UN-Economic Commission for Europe (UN/ECE-CLRTAP). CCE holds a UN/ECE-LRTAP mandate to develop critical thresholds - for the deposition and ambient concentration of air pollutants - beyond which ecosystems become subject to risk of damage. As such, critical thresholds can be regarded as indicators for ecosystem sustainability. The report provides results of critical loads for acidification and eutrophication and critical levels for tropospheric ozone. Maps of critical thresholds and their excess are included. The report also includes an extensive analysis of the reliability of critical loads and their background data. Critical thresholds are then used in the RAINS model to assess emission reductions of acidifying and eutrophying pollutants as well as chemical oxidants in terms of costs and ecosystem protection. RAINS and CCE critical thresholds are currently also being used for the scientific support of the acidification and ozone strategy development of the EU. Finally, the report contains 20 contributions of the scientific institutions which are part of the CCE network to assess critical thresholds.
Posch M, Hettelingh JP, de Smet PAM, Downing RJ
RIVM Rapport 259101007