The amount of solar radiation reaching the earth is reduced by reflection of the light on (manmade) aerosol particles. This effect presents the major uncertainty in quantifying climate change by the increase in greenhouse gas emissions. The dominant reason for the uncertainty is the localized character of aerosol. It is the aim of the present study to quantify the effect of anthropogenic aerosol on the local climate in Europe. This is realized along three interconnected approaches. First, empirical factors stemming from measurements in the US and used in the present estimates of the reflection of solar radiation by anthropogenic aerosol are checked for their validity in the European domain. Secondly, historical data on solar flux in Europe are related to the historic trend in aerosol loading. Finally, a sophisticated aerosol and cloud (radiation) module is developed for incorporation in a climate model. The radiation module uses aerosol characteristics as measured in the field and is validated via solar radiation measurements. Since the study recently started only preliminary results are reported. 1 fig., 13 refs.