Environmental impact of electricity generation electricity sector is unique among industrial sectors in its very large contribution to emissions associated with nearly all air issues. Electricity generation produces a large share of Canadian nitrogen oxides and sulphur dioxide emissions, which contribute to smog and acid rain and the formation of fine particulate matter. It is the largest uncontrolled industrial source of mercury emissions in Canada. Fossil fuel-fired electric power plants also emit carbon dioxide, which may contribute to climate change. In addition, the sector has significant impacts on water and habitat and species. In particular, hydro dams and transmission lines have significant effects on water
Emission standard limit that sets thresholds above which a different type of emission control technology might be needed. While emission performance standards have been used to dictate limits for conventional pollutants such as oxides of nitrogen and oxides of sulphur (NOx and SOx), this regulatory technique may be used to regulate greenhouse gasses, particularly carbon dioxide (CO). In the US, this is given in pounds of carbon dioxide per megawatt-hour (lbs. CO/MWhr), and kilograms CO/MWhr elsewhere. In Canada, the Canadian Environmental Protection Act, 1999 (CEPA 1999) transfers the legislative authority for regulating emissions from on-road vehicles and engines to Environment Canada from