Modelling and Mapping of Critical Thresholds in Europe

In 2003 this database underwent a first time extension with dynamic modelling variables. This information is necessary to support European air quality policies with knowledge on time delays of ecosystem damage or recovery caused by changes, in time, of acidifying deposition. The database was updated and extended following the request of the Working Group on Effects at its 21st session (Geneve, 28-30 augustus 2002). Nineteen countries submitted data on critical loads for acidity and eutrophication. Ten countries also submitted the requested dynamic modelling parameters. Other countries indicated their intentions to prepare data for submission for the next call planned for the autumn of 2003.

It is concluded that minimum data requirements for dynamic modelling can be met. The report contains national reports on the methods applied to contribute to the European critical loads data base. The report includes an analysis of the data to verify cross border consistency. A comparison is made with the database used to support negotiations of the 1999 CLRTAP Protocol to Abate Acidification, Eutrophication and Ground-level Ozone (the "Gothenburg Protocol") and the 2001 EU National Emission Ceiling directive. The results described in this report are important for the next step in the support of the revision process of these European agreements expected in 2004/2005. The report will be presented at the 22nd session of the Working Group on Effects (Geneva, 3-5 September 2003).