The energy sector, as defined by the IPCC, comprises all energy extraction, conversion, storage, transmission and distribution processes with the exception of those that use final energy in the enduse sectors (industry, transport, building, agriculture, forestry). Three climate-change phenomena will have a particular impact on the energy sector: global warming, changing regional weather patterns (including hydrological patterns) and an increase in extreme weather events. Not only will these phenomena affect energy demand, in some regions they will also affect the entire spectrum of energy production and transmission. While most climate change impacts are likely to be negative, there could be some positive impacts such as lower energy demand in cold climates.