[en] It is widely recognized in the discourse on global environmental change that anthropogenic activities, and particularly the combustion of fossil fuels, are having a discernible impact on the earth's climate. Concern over a looming environmental crisis has led to an international response, initially with the United Nations Framework Convention on Climate Change (UNFCCC) in 1992, followed by the Kyoto Protocol in 1997. Much of the national debate on climate change has focused predominantly on the technological options to reduce greenhouse gas (GHG) emissions, and more directly on the costs associated with taking mitigation actions. However this focus has come at the expense of not fully considering other dimensions of climate change, specifically the costs associated with climate change impacts and effects, the costs of adaptation actions, and the co-benefits for environment and health that could result from GHG plus related emission reductions. This is perhaps most apparent in the discourse on climate change and energy, especially in regards to electricity generation, where there is greater attention directed at the implications of climate change policies rather than the actual impacts and effects arising from climate change. In this paper it is argued that the issue of climate change and energy needs to be examined within a broader conceptual framework. Situating climate change and electricity generation within this broader context is essential in developing a sustainable energy system. The paper is organized into four sections. In section one, the conceptual framework is described, highlighting the importance of considering all dimensions of climate change (vulnerability, co-benefits and costs) in developing a sustainable energy system. Section two focuses more directly upon the relationship between climate change impacts and the energy sector, specifically in terms of generation (nuclear, hydro, fossil fuel, and alternatives), distribution and transmission (electricity and natural gas), and the demand for energy. Climate factors considered include changes in the mean, but more importantly variability in temperatures and changes in extreme weather events. This part of the discussion draws upon extensive research in the Toronto-Niagara Region, which has been supported through the Federal Interdepartmental Panel on Energy Research and Development (PERD). Emphasis is placed on identifying what aspects of current climate have had the greatest impact on the energy sector, and the adaptation options that will be necessary to reduce future vulnerability in face of inevitable climate variability and change. In section three, the emphasis shifts towards actions to reduce GHG plus related emissions, within the context of environmental and health benefits. The co-benefits of reducing GHG plus related emissions includes the implications for ecosystems and biodiversity, environmental health (managed (forestry) and unmanaged (agriculture) systems), social welfare and human health. This discussion is based on research conducted on co-benefits as part of the multi-stakeholder process to develop a national strategy on climate change. The paper concludes by providing a preliminary assessment of the various mitigation options currently being proposed to help reach emission targets set out in the Kyoto Protocol, as they apply to the Toronto-Niagara Region. The assessment, which will be undertaken in greater depth as part of Phases III through V of the PERD supported project, considers the vulnerability of an altered energy system to climate change impacts, and the potential co-benefits for environment and health This includes changes brought about by fossil fuel switching, the inter-provincial transmission of electricity, alternative technologies, and energy efficiency, amongst other mitigation actions. (author)