The City of Toronto has a long history of pursuing environmental objectives. Improving air quality and reducing greenhouse gas (GHG) emissions continue to be important City objectives. Toronto was one of the first cities in the world to make a formal commitment to address local GHG emissions when, in 1990, Toronto City Council passed a resolution to reduce carbon emissions by 20%. 

In 1991, Toronto City Council approved the establishment of the Toronto Atmospheric Fund (TAF).   At the request of the City, the provincial government enacted the Toronto Atmospheric Fund Act in 1992. The Act established the Toronto Atmospheric Fund (TAF), an agency of the City of Toronto and the Toronto Atmospheric Fund Foundation (now CAP) as statutory corporations. The TAF Foundation was renamed the Clean Air Partnership (CAP) and was registered under the Income Tax Act effective 1996. 

As a charitable organization, CAP operates at arms-length from the City and TAF, and uses program dollars secured from sponsorships, contracts and donations to implement its programs. Some notable exceptions are the annual Clean Air and Climate Change Summit and GTA Clean Air Council: TAF provides CAP with the City of Toronto's annual financial contribution to these programs.