Urbanization and climate change willdefine much of the 21st century. Urbanization leads toimprovement in standards of living, and through theincreased density and service delivery efficiency of cities,higher growth can be achieved with lower greenhouse gasemissions. Cities and urban agglomerations house more than50 percent of the global population and contribute more than70 percent of Global greenhouse (GHG) emissions. As theshare of urban population grows, sustainable urbandevelopment emerges as an essential component in addressingclimate change. Mitigation often comes at a significantcost. Carbon finance has an important role to play inreducing these costs. Carbon finance is accessible throughregulated mechanisms, such as the Clean DevelopmentMechanism (CDM) and Joint Implementation (JI) under theKyoto Protocol, and through voluntary markets, using thevoluntary carbon standard and climate exchanges. Cityauthorities, however, have not been able to fully accessmarket mechanisms for carbon credits.