The overall objective of the Swedish Clean Air and Climate Research Programme (SCAC) financed by the Swedish Environment Protection Agency (SEPA) is “To develop and improve the scientific basis for air pollution policies on national and international scales”. The present report summarizes the key findings of the Phase 1 of the programme (November 2013 – March 2017). The program has been successful in generation new knowledge in several areas for direct importance for both national and international policy. The international part covers results to be implemented within the CLRTAP, the EU and the Arctic Council. Some of the key findings are listed below: • A Scandinavian version of the GAINS model was developed, by which it is possible to opt...