Urban areas include the land we use for homes, businesses, and roads. In this section we use the term urban in general, to refer to human habitats, including suburban.

Many problems we face are largely due to the ways we have planned and built urban environments. Those problems include traffic congestion, loss of open space, and degraded air and water quality. We've used land inefficiently. We have paved over prime farmlands, built sprawled communities without providing effective mass transit, and destroyed important habitats, accelerating extinction rates.

In the past, many land use and management decisions were based on immediate economic returns, without full regard for environmental and quality of life costs and considerations. Today, it is essential that we comprehensively evaluate the potential consequences of land use conversion. Some factors to consider include the efficient use of land and natural resources, costs to ecosystem services, community livability, and economic benefits. With more thorough evaluation and planning, we can make meaningful land use decisions and invent sustainable solutions.

As in native habitats, the natural cycles of air, water, nutrients, and energy flow through urban ecosystems. Urban structures often short-circuit natural cycles, interrupting nature's ability to function effectively. We can alter some components of urban environments, to reduce the negative impacts on natural processes.

To become sustainable, we must rethink the ways we: manage, plan, and build urban areas.