What it is a sustainable city? is a city designed with consideration of environmental impact, inhabited by people dedicated to minimization of required inputs of energy, water and food, and waste output of heat, air pollution - CO2, methane, and water pollution.
How do we make cities sustainable? There are many ways in which cities can be sustainable, here are some ways to make/improve a sustainable city.
Improve mass transit: Around the world, urban commuters spend hours each year stuck in traffic congestion, burning through gasoline just idling in road jams. Use of public transit is increasing in some places, but not at the pace most experts say is needed. Roadway occupancy levels could increase sixfold in some countries, according to the International Energy Agency (IEA). Would better mass transit systems get more commuters off the road?
Make buildings more efficient: In the developed world, fully 40 percent of carbon dioxide emissions come from heating, cooling, and powering buildings. Many countries have embarked on major efforts to better insulate buildings and install more modern and efficient heating and ventilation equipment. Energy savings could reach 30 percent or more. Should cities invest in major weatherization and energy upgrade efforts?
Preservation of historic and natural assets: Part of what makes each city unique is its architecture. Preserving buildings, and the history and culture they embody, is often difficult for cities as they face the pressure of growing population and changing economic demands. Natural assets, like waterways, parkland, and wetlands, also are a key factor in making cities livable. How important is it to integrate preservation into city planning?
Boost clean energy: The electricity plants that power the world's cities are often out of sight and out of mind. But some municipalities are taking steps to reduce their reliance on power transmitted from distant generating stations. Cities are integrating solar energy onto rooftops, capturing and recycling waste heat, and purchasing wind power. Switching from coal to natural gas also can cut carbon emissions and other pollutants.
Upgrade power infrastructure: As New York City learned during Hurricane Sandy, aging energy delivery systems in many cities need to be upgraded to handle increased weather and flooding risks as well as growing population. Cities will need smarter and more resilient electricity and fuel delivery systems to provide basic human services, and for communities to grow and thrive into the next century.