In 2005, the Canadian electric infrastructure was to a large extent under provincial jurisdiction  and comprised generation, transmission and distribution. Provincial authorities exercised their jurisdiction through provincial Crown utilities1 and provincial regulatory agencies. Historically, electricity was supplied by vertically-integrated electric utilities that were often Crown corporations with monopoly rights.
The earth's climate has suffered through many changes over time, with events ranging from ice ages to warm, interglacial periods (such as the present era) documented.
The National Pollutant Release Inventory (NPRI) of Environment Canada collects data on pollutant releases and transfers and compiles and reports comprehensive emission summaries and trends for key air pollutants, based on facility-reported data and emission estimates for other sources.
Table 2.1 shows a summary of the information obtained for this report for the 189 fossil fuel-based power stations in Canada for year 2005. Data for electricity generation were only available for 91 of 189 facilities, as indicated in the table footnote. However, all 189 facilities operated in 2005, with each plant reporting emissions of at least one of the pollutants under consideration in this report.