While the energy sector is a primary target of efforts to arrest and reverse the growth of greenhouse gas emissions and lower the carbon footprint of development, it is also expected to be increasingly affected by unavoidable climate consequences from the damage already induced in the biosphere. Energy services and resources, as well as seasonal demand, will be increasingly affected by changing trends, increasing variability, greater extremes and large inter-annual variations in climate parameters in some regions. All evidence suggests that adaptation is not an optional add-on but an essential.