Cities represent a major contributor ofgreenhouse gas (GHG) emissions. According to the UnitedNations Population Fund,1 half of the world'spopulation now lives in cities and is responsible for 75% ofglobal energy use and GHG emissions. Since the world'spopulation will continue to grow, and rapid urbanizationwill continue particularly in the developing world, tacklingclimate change issues in the urban context will beessential. In response to these challenges, the WorldBank's Energy Sector Management Assistance Program(ESMAP), in cooperation with the Bank?s Finance Economicsand Urban Department (FEU), has launched an Energy EfficientCities Initiative, which is designed to help mainstream andscale-up sustainable energy and climate change mitigationactions and investments in the urban context. The firstactivity proposed under this Initiative is the EnergyEfficient Cities Practitioners Roundtable, a facilitateddiscussion cohosted by ESMAP and FEU. The purpose of thisevent was to bring together client cities and partnerorganizations to investigate ongoing initiatives andprograms to support cities' sustainable energy goalsneeds and develop an Energy Efficient Cities Action Planthat will outline a vision and subsequent actions to betaken under the Initiative. The event took place at theWashington DC offices of the World Bank, from October 20-21, 2008.