Planning an eco-city
Many countries are now experimenting with the development of greenfield 'eco-cities' that are planned from scratch and built around the principle of achieving reduced - or even zero - emissions.
Urban planning for eco-cities is quite unlike traditional city planning. For one, eco-planners need to understand the resources available to the city and what activities those resources can support. "The very first thing that eco-cities need to focus on - before breaking ground on a single building - are the three big considerations of environmental urban planning: water, energy and waste," advises Dr. Anne Kerr, Director Sustainable Development at Mott MacDonald in Hong Kong. "For most urban planners, that means really turning the planning process around on its head."
Making existing cities more eco-friendly
The bigger challenge, however, will be in 'greening' the world's existing cities. Here, many governments are turning to sustainable mass transit systems to achieve a portion of their carbon reduction goals. And while the focus must be on low-carbon alternatives, it is equally important to develop a system that is both efficient and competitive. "If the sustainable transit option is twice as expensive as the higher-polluting alternative, it will never be successful," notes Dr. Kerr. "Very few people will pay more for transit based on altruistic reasons alone."
But every city is unique and each brownfield project must be explored within the context of the city's environment and resources. For example, cities such as Hong Kong, London and New York already enjoy highly-efficient, low-carbon mass transit systems and will therefore need to seek other solutions to further reduce their carbon footprint.
Using less H2O to reduce CO2
One significant - but often overlooked - opportunity comes from reducing water consumption. "Water treatment requires substantial amounts of energy, particularly in locations with scarce natural water sources," noted Dr. Kerr. "In the Americas and Asia where per capital water consumption often tops 300 liters per day, cities can dramatically reduce their carbon footprint by working with consumers to bring water use down to a more sustainable level - somewhere in the range of 150 liters per capita per day."
But changing human behavior - a key requirement of sustainability - is often the hardest task for governments. Financial incentives are generally seen as the most successful approach, but often require authorities to develop clear policies to ensure that consumers share in the financial savings that are delivered.
The future is green
Dr. Kerr is optimistic that cities can make a difference in the global effort to reduce carbon emissions. "Once people saw the hole in the ozone layer as a serious risk to human health, the world came together to form an immediate and effective response," notes Dr. Kerr. "So I believe that with collective action and collaboration between people, companies and governments, we can also make a very positive way cities interact with the environment."