Climate change has been on the OECD agenda since the late 1980s. As an intergovernmental organisation, the OECD represents 32 member countries committed to common principles to support economic development including social and environmental protection. We help governments to improve their collective and individual performance of climate change policies through peer reviews, dialogue and shared policy assessments. We provide an objective forum, away from international negotiations, for countries to discuss and develop a shared understanding of good practice on climate policy issues.

This book is the result of a joint project overseen by two Working Parties of the OECD: the Working Party on Territorial Policy in Urban Areas under the Territorial Development Policy Committee, and the Working Party on Global and Structural Policies under the Environment Policy Committee.

Roughly half of the world’s population lives in urban areas, and this share is increasing over time, projected to reach 60% by 2030. Cities consume a great majority – between 60 to 80% – of energy production worldwide and account for a roughly equivalent share of global CO2 emissions. Greenhouse gas (GHG) emissions in OECD cities are increasingly driven less by industrial activities and more by the energy services required for lighting, heating and cooling, electronics use, and transport mobility. Cities can in principle use energy in a more efficient way than more dispersed areas because of reduced costs and economies of scale, however this depends on urban design and form. Growing urbanisation will lead to a significant increase in energy use and CO2 emissions, particularly in non-OECD countries in Asia and Africa where urban energy use is shifting from CO2-neutral energy sources such as biomass and waste to CO2-intensive energy sources.

Climate change is one of the most pressing issues of this century. World greenhouse gas emissions (greenhouse gas) have roughly doubled since the early 1970s, reaching about 42 gigatons CO2 equivalent (Gt CO2eq) in 2005 (IEA, 2009). Recent OECD and IEA work suggests that if we continue on the present high emission trajectory, global greenhouse gas emissions will increase by more than 50% by mid-century, causing world mean temperatures to rise 4 to 6° Celsius (°C) above pre-industrial levels by the end of the century and more in the long term (OECD, 2009; IEA, 2009). In addition, the planet’s natural system to absorb carbon will peak by mid-century and then likely weaken, possibly making climate change much more acute (IPCC, 2007a).