The role of cities in sustainable development

The increasing importance of cities for the environment makes the “Green Cities” theme of World Environment Day 2005 very timely. The environmental problems of cities in developing countries, and especially megacities, are posing serious health threats to many urban residents. Cities are also making increasingly important contributions – both positive and negative – to environmental issues at the national, regional and global levels.

While the process of urbanization has come to a halt in the developed world, cities in developing countries are still growing rapidly, gaining a combined total of 60 million people per year. Most of this growth takes place in poorer neighbourhoods. For example, Dar es Salaam is growing at an annual rate of 6 percent, which implies that its population is doubling every 12 years. In 1950 there were 86 cities of more than one million inhabitants, while today there are 380 – the great majority in the developing world.

We need to find ways to address the problems and to manage urbanization in developing countries. Many of today’s problems result from poor management of the urbanization process and from ignoring the link between environment and development.

Cities as good neighbours

Ensuring sustainable urbanization is not only an urban issue. Most cities get their natural resources from the surrounding rural areas. For example, cities often rely on the drinking water from nearby water catchment areas, which include wetlands, mountains and forests. These protective wetlands and woodlands are often under pressure from the cities themselves due to expansion, the cutting of trees for building materials and cooking, and so forth. This urban-rural link is most important.

As much as cities are part of the problem, they are also part of the solution. There is a clear need to involve cities, and especially developing country megacities, in creating policies and action plans to address important environmental issues. Cities are often vital to realizing environmental policies agreed at the national, regional and global levels.

For example, national governments are working through UNEP’s Global Programme of Action for the Protection of the Marine Environment from Land-based Activities to protect regional seas from land-based pollution. As coastal cities are often a major source of sewage pollution, these cities are asked to develop programmes to reduce sewage dumping into the seas.

Climate change

Fortunately, win-win situations often exist: addressing environmental issues within cities improves the lives of urban dwellers and at the same time contributes to addressing global or regional environmental issues. A good example is climate change. At present, most of humanity’s carbon dioxide emissions originate from cities. Therefore, global efforts to reduce greenhouse gas emissions need to include cities. But local and global concerns can be combined, as addressing local air pollution can also reduce CO 2 emissions.

More broadly, cities will have to play a key role over the next few years in implementing the Millennium Development Goals (MDGs). It is no exageration to say that, in many ways, the battle for sustainable development and the success of these Goals will be won or lost in our cities.

(Published in Environment House News No 12, June 2005, Geneva, www.environmenthouse.ch)