The International Commission on Atmospheric Chemistry and Global Pollution (CACGP) is one of the commissions of the IAMAS (International Association of Meteorology and Atmospheric Sciences,whish in turn is one of the Associations within IUGG (International Union of Geodesy and Geophysics) under the nongovernmental ICSU (International Council of Scientific Unions) family.The main goals of CACGP are: promote research on chemistry and composition of the troposphere related to global pollution and climate change; initiate facilitate and coordinate the research programs in this filed which require international cooperation; stimulate discussion and provide publication of results of such research programs.The major activity of CACGP has been to organize scientific symposia approximately every four years.CACGP has endorsed scientific projects like IGAC (jointly with IGBP) and SOLAS (jointly with IGBP and SCORE).In addition to organizing the quadrennial symposia and developing research projects,CACGP sponsors and cosponsors many symposia in connections with general assemblies organized by IUGG and IAMAS every two years.