This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.
Agenda 21 estimates roughly that the construction activities of developing countries amount to about US$ 400 billion annually and increase by about $20 billion annually. The stream of new investments for these levels of activity and to bring in clean technologies is estimated at $40 billion annually, primarily from private sources. If 10% of the new investments came from the international community, this would amount to US$ 4,000 million annually. About US$ 3 million would be needed to strengthen international organizations.