The main objective of the proposed study was to assess to what extent we could use satellite observations to detect the ecosystem-scale impact of the air pollutant ozone on plant photosynthesis. Current estimates of this impact are mainly based on laboratory experiments. Alternatively, we studied this by combining satellite observations with an European-scale air quality model. This included use of satellite observations of gases such as nitrogen dioxide that result in the formation of ozone. However, the study also revealed that apparently the quality of current ecosystem-scale vegetation products is not yet sufficient to allow detection of this ozone impact.