Perlman Principles

1. There can be no global environmental sustainability without urban environmental sustainability.

Circular rather than linear systems: As cities concentrate pollution and environmental degradation, transforming the urban metabolism through circular rather than linear systems is the key to reversing our global environmental deterioration. We need to re-use our water and waste streams, and utilize what is now discarded as productive resource.

2. There can be no urban environmental solution without alleviating urban poverty.

The urban poor tend to occupy the most ecologically fragile areas of our cities, such as steep hillsides, low-lying swamplands, or adjacent to hazardous industries. In addition, their lack of resources often prohibits them from having adequate water, sewage, or solid waste management systems. Without alternative locations to settle and sufficient income to cook and keep warm, their survival will increasingly be pitted against environmental needs.

3. There can be no lasting solutions to poverty or environmental degradation without building on bottom-up, community-based innovations, which are small in scale relative to magnitude of the problems.

The most creative and resource-efficient solutions to urban problems tend to emerge at the grassroots level, closest to the problems being solved. And, without local participation in implementation, even the best ideas are doomed to failure.

4. There can be no impact at the macro level without sharing what works among local leaders and scaling these programs up into public policy where circumstances permit.

While small may be beautiful, it's still small. In order to have meaningful impact, micro-initiatives need to be replicated across neighborhoods and cities through peer-to-peer learning or incorporated into public policy frameworks.

5. There can be no urban transformation without changing the old incentive systems and "rules of the game," and the players at the table.

Since every sector of urban society holds a de facto veto on the others, local innovations can never achieve scale with cross-sectoral partnerships involving government, business, NGOs, academia, media, and grassroots groups. We need to create a climate conducive to experimentation, mutual learning, and collaboration.

6. There can be no sustainable city of the 21st Century without social justice and political participation, as well as economic vitality and ecological regeneration.

Innovations that promote ecological regeneration are just one piece of the puzzle. It is only by seeking out innovations in social equity, participatory democracy, and economic productivity -- and ideally, innovations that possess all four attributes -- that our cities can be truly be sustainable for the 21st Century and beyond