Forty years after the United Nations Conference on the Human Environment in Stockholm—the first global forum to highlight the importance of sustainable development—progress on promoting environmentally responsible economic growth remains disappointingly limited. In part, national governments and inadequate local engagement are to blame. But it may also be the case that competition and imbalances among advanced and emerging economies today are making global cooperation increasingly difficult. An alternative framework harnessing the growing weight of cities and directing resources toward the scaling-up of local initiatives could prove more workable.

Disappointment after the Earth Summit

Broadly speaking, sustainable development refers to development and growth that minimizes long-run economic, environmental, and social damage. The purpose of the UN Earth Summits has been to highlight the trade-offs involved in development and to serve as a vehicle for implementing sustainable development initiatives. On the second count at least, the summits have fallen far short of expectations. The most recent, Rio+20 in June, yielded a communiqué ratified by all UN members but resulted in no financial commitments, binding agreements, or concrete benchmarks.

In the absence of binding internationally agreed-upon targets, global economic development has continued on an unsustainable path. Global carbon emissions have outpaced most projections. The United States and China, the world’s largest emitters and greatest contributors to the 2010 increase in global carbon emissions, have yet to adopt binding targets. Meanwhile, a slow global economic recovery and increased competition have spurred other major economies like Canada and Japan to relinquish carbon-reduction commitments.

Shifting the Focus from Global to Urban

An alternative sustainable development framework could be built by drawing on the global network of cities and through the engagement of subnational actors. There are at least three reasons why cities could form the locus of a comprehensive sustainable development program.

First, the world is becoming increasingly urban. Since the first Rio conference on sustainable development twenty years ago, the majority of the world’s population has become concentrated in urban areas—including a rapidly growing global middle class. This trend is set to continue. The UN estimates that by 2050 at least 67 percent of the world’s population will live in cities.

Second, cities have higher economic growth prospects and, therefore, offer more job opportunities. The 200 largest metropolitan regions in the world account for just 14 percent of the world’s population but 48 percent of global GDP. Per capita income growth in cities, moreover, sometimes outpaces national growth—a gap that is particularly stark in many emerging economies. Billions of people will thus be relocating to urban areas to improve their quality of life.

Third, there is still great potential to drive down carbon emissions and energy consumption by focusing on the ways cities are built and managed. Urban population growth has not yet peaked, so the development of cities will continue for decades. Planners have the opportunity to develop these urban areas worldwide in low-carbon ways. China’s population only recently became majority urban, and in India, urban residents account for around 36 percent of the total population. Over the next thirty-five years, the fastest rates of urban growth will be in Asia and Africa.

While emerging economies have an opportunity to forge a new development path with their cities, mature economies will need to renew their existing urban infrastructure to meet ever-changing environmental and economic opportunities and challenges.

Progress at the Local Level

Focusing sustainable development efforts at the city level also makes sense because subnational governments and institutions are already forging ahead. Municipal leaders have multiple tools and strategies at their disposal to reach sustainable development goals; they control local budgets, can set policies and enforce regulations, levy fees and charges, develop visions, and create plans.

Many local leaders are in fact crafting long-term sustainability plans as part of their economic development programs. New York City’s PlaNYC is one example of a program that integrates economic development and sustainability goals. Like national leaders, city leaders are sharing best practices and developing policy frameworks. But because they are smaller, they can adopt these more quickly than national governments can.

The Making of a Low-Carbon Urban Policy Toolkit

As regions and cities address the challenges of global urbanization, three courses of action are particularly important in the absence of a binding international agreement on sustainable development.

First, urban transportation systems should be decarbonized as much as possible. Efficient, integrated transport systems coupled with supportive land-use policies can greatly enhance long-term sustainable development and support economic growth, as emissions from the transport sector will contribute more to climate warming than those from any other sector in the near term. Sustainable transportation improvements usually provide numerous social and economic benefits. For example, improving infrastructure for nonmotorized travel would reduce road fatalities, one of the leading causes of preventable deaths of children. It would also mitigate air pollution and encourage physical activity through walking and biking, which could lower health-care costs stemming from obesity and diabetes. Reducing the amount of land paved with asphalt for roads and parking would reduce storm-water runoff and prevent harmful pollutants from entering waterways and drinking-water systems. Sustainable transportation improvements could also support economic growth by alleviating congestion and facilitating access to markets.

Those low-carbon transportation systems should be designed to optimize the use of space. For urban areas that are already developed or are maturing, this means transitioning to a more holistic approach to mobility that incorporates public transit, walking, and biking. New cities can avoid falling into energy-intensive patterns by implementing mixed-use development that co-locates residential and commercial uses. Fuel-efficient systems, including electric vehicles, should only be considered if heavy usage for each vehicle is expected, for example through shared fleets.

Second, national governments should remove barriers to local governments’ ability to structure sustainable development financing schemes and should provide more direct funding for cities. Of course, fiscal constraints will continue to challenge governments at all levels. Project prioritization analysis should therefore expand economic impacts to include social and environmental benefits in order to maximize returns on investment. Infrastructure funds assembled by the city government for local projects, such as the one recently launched by Chicago, or increased access for cities to international sources of financing would provide mayors with more leverage and flexibility to finance critical green infrastructure within a shorter timeframe. But additional financing alone will not ensure the success of sustainable development initiatives. Helping more cities access, set up, and deploy those funds is critical. Providing performance benchmarks for such financing tools is also important.

Third, knowledge transfers should be facilitated within and among cities. While formal knowledge sharing between cities through coalitions like ICLEI and C40, a worldwide group of 58 cities sharing best practices for climate change mitigation, has accelerated the adoption of sustainable development goals, more can be done in the area of open data, for instance. A critical component of knowledge sharing is to increase the liquidity and consistency of urban data so that cities can compare apples to apples and make decisions quickly.

Significant gaps in data quality and availability remain, though this situation is being remedied through the World Bank’s proposed standardization of sustainability indicators. When knowledge sharing is coupled with greater transparency of governmental activity, there will be an opportunity to build public support for sustainable development projects. Open engagement between the public and government would, for example, reduce the friction involved in start-up activities and ease the implementation of policy changes.

These priorities form the basis of an urban policy toolkit that could bring about an international paradigm shift to achieve sustainable development through the world’s cities. Cities require greater visibility in the international arena to gain the policy support they will need to fully achieve their sustainability initiatives. But what is more important in the near term is greater acknowledgement of the role urban centers and their leaders play in the global economy and in the sustainable development arena. If international policymakers want to have a fighting chance of overcoming climate change challenges, they should recognize the vital contributions cities can make.