Zurich. The analysis of a wide range of solar radiation data in tens of observatories scattered throughout the Italian territory, has permitted to study how this important amount has changed over the course of 55 years. The study was published in the journal Atmospheric Chemsistry and Physics and is the result of a collaboration between the State University of Milan, ETH Zurich, ISAC-CNR, Aeronautic Militare and IPE-CSIC of Saragozza. The lead author is a young PhD student from the School of Environmental Sciences of the State University of Milan. (9colonne)