The Kyoto target set for Canada is to reduce GHG emission by 6% of the 1990 level by 2008-2012. Several options are being considered to achieve this target. For deep reductions within the next decade or two, CO2 sequestration is the only option if fossil fuel power plants, in particular coal based plants, are to remain in operation. In the case of Ontario, the only sequestration option is geological sequestration in saline aquifers, where CO2 is expected to be stored for long geological periods, from one hundred to several thousand years depending on the size, properties and location of the reservoir. The preferred concept is to inject CO2 into a porous and permeable reservoir covered with a cap rock located at least 800 in beneath the earth's surface where CO2 can be stored under supercritical conditions. The injection pressure and temperature should be above the critical temperature and pressure Of CO2 (31.1degreesC and 7.38 MPa). This is the first study of its kind in Ontario. Two different major reservoirs with approximate storage capacities of 289 million and 442 million tonnes are identified in southwestern Ontario for CO2 sequestration, one located in the southern part of Lake Huron and the other located inside Lake Erie. These reservoirs might contain approximately 14-21 years Of CO2 emissions from a nearby coal-fired power generation unit having a total generation capacity of about 4000 MW. (C) 2004 Elsevier Ltd. All rights reserved.