Review and revision of empirical critical loads of nitrogen for Europe

This report describes the scientific background and results from the review and revision of empirical critical loads of nitrogen that had been established for Europe in 2011 under the
auspices of the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP Convention). In 2020, the Coordination Centre for Effects started a project under the LRTAP
Convention to bring empirical critical loads up to date. New relevant information from studies (2010 - summer 2021) on the impacts of nitrogen on natural and semi-natural cosystems was incorporated in the existing European database on empirical critical loads of N (CLempN). The current review and revision used for the first time gradient studies to evaluate and determine the ClempN. The CLempN were structured according to the updated classification used within the European Nature Information System (EUNIS).