As the world continues to urbanize at an unprecedented pace, cities consume an increasingly larger share of the planet's resources. Therefore they are often the locus of the planet's most serious environmental problems. For that reason, cities at the same time are the places where a sustainable future can be promoted. This challenge however cannot be addressed by cities working in isolation, but must be taken up by partnerships between and among local governments, utilities, universities, businesses, non-governmental, community-based, or international organisations. This publication profiles twelve worldwide examples of local government achievements towards sustainability and the specific partnerships with a variety of actors that have contributed to that success.