The Melbourne Principles were adopted at the Local Government Session of the Earth Summit 2002 in Johannesburg, as part of the final communique, known as Local Action 21 or the Johannesburg Call. They consist of ten short statements on how cities can become more sustainable. Each principle has a few paragraphs of elaboration that provides additional information on its meaning and application. The Principles are designed to be read by decision-makers, and provide a starting point on the journey towards sustainability. Additional tools will be needed to operationalize the Melbourne Principles.