United Nations Global Statistics - Statistics gathered through the UN regarding member nations.
The World Bank: Data - The World Bank provides free and open access to a comprehensive set of data about development in countries around the globe, together with other datasets cited in the data catalog
Canadian Institute for Health Information (CIHI)
Fisheries and Oceans Canada Statistics
National Air Pollution Surveillance Program (NAPS)
National Climate Data & Information Archive
National Energy Use Database (NEUD)
National Pollutant Release Inventory (NPRI)
Various department, ministry or city websites