For many years, research into SRM was only publicly funded to a limited extent. Private funding, mainly from philanthropic institutions, was the main source. More recently, growing interest from both the public and private sectors has been reported, although concrete data on expanded funding streams is limited and the overall scale and direction of this investment remains unclear This factsheet attempts to trace the evolution of Solar Radiation Modification (SRM) project initiatives and their financing. It is based on the project overview table linked below.