The Potential Impacts of a Scenario of CO2-Induced Climatic Change on Ontario, Canada

In 1984, Environment Canada, Ontario Region, with financial and expert support from the Canadian Climate Program, initiated an interdisciplinary pilot study to investigate the potential impact, on Ontario, of a climate scenario which might be anticipated under doubling of atmospheric CO2 conditions. There were many uncertainties involved in the climate scenario development and the impacts modeling. Time and resource constraints restricted this study to one climate scenario and to the selection of several available models that could be adapted to these impact studies. The pilot study emphasized the approach and process required to investigate potential regional impacts in an interdisciplinary manner, rather than to produce a forecast of the future. The climate scenario chosen was adapted from experimental model results produced by the Goddard Institute for Space Studies (GISS), coupled with current climate normals. Gridded monthly mean temperatures and precipitation were then used to develop projected biophysical effects. For example, existing physical and/or statistical models were adapted to determine impacts on the Great Lakes net basin supplies, levels and outflows, streamflow subbasin, snowfall and length of snow season. The second phase of the study addressed the impacts of the climate system scenario on natural resources and resource dependent activities. For example, the impacts of projected decreased lake levels and outflows on commercial navigation and hydroelectric generation were assessed. The impacts of the climate scenario on municipal water use, residential heating and cooling energy requirements, opportunities and constraints for food production and tourism and recreation were determined quantitatively where models and methodologies were available, otherwise, qualitatively. First order interdependencies of the biophysical effects of the climate scenario and resource dependent activities were evaluated qualitatively in a workshop format culminating in a series of statements on (i) possible preventive, compensatory and substitution strategies and (ii) an assessment of current knowledge gaps and deficiencies, with recommendations for future areas of research.