This 1971 document from Imperial Oil Ltd, the Canadian subsidiary of Exxon, is a presentation on “The Economic Implications of Environmental Protection,” particularly as they relate to stationary emissions. This document is part of the ClimateFiles Imperial Oil document set, gleaned by DeSmog researchers from the Glenbow Imperial Oil Archive Collection.

The presentation includes such observations as that “thermal electric plants are the largest contributions to total emissions by a large margin,” and that “coal is the worst offender contributing about 25% more nitrogen and sulphur oxides and about 15 times as much particulate matter as heavy fuel oil.”