Plan Green Cities for the Planet

As cities grow- from migration or from increases in population- their inhabitants need a well-planned, clean, healthy and safe environment in which to raise their children and pursue their dreams. - Kofi Annan, UN Secretary-General

All across the world more and more of us are living in cities. People first started banding together in permanent settlements some 8000 years ago in southwest Asia and reaped the benefits of specialisation of labour. Most, however, continued to live and work on the land as farmers or hunter-gatherers.

A few centuries ago technological advances led to a huge increase in food production. This meant that fewer farmers were needed and many moved to towns and cities looking for work. This trend is continuing across the globe. Today, cities are swelling with people and continuing to sprawl outwards causing much concern about their environmental impact both within the city itself and on the surrounding areas. Amazingly, around one million people move to a city every week.

Cities are like ecosystems. What happens within a city has an impact on all the elements of that city. How a city is organised and the activities that take place within that city have consequences for the flow of resources. Cities are by their nature highly concentrated centres of population within a limited geographical space, putting pressure on the natural habitat of the surrounding regions as well as on the city's environment itself. A city will draw on resources from outside the city boundaries like energy and water. In turn, the use of these resources generates products and waste which often end up outside the boundaries of the city. Cities now consume 75% of the planet's natural resources.

The average city of 1 million people requires around 11 000 tonnes of fossil fuels, around 300 000 tonnes of water and 2 000 tonnes of food every day. At the same time, it produces 300 000 tonnes of waste water, 25 000 tonnes of carbon dioxide and 1 600 tonnes of solid waste each day. This results in many environmental stresses like poor air quality, the using up of scarce energy resources and the loss of green spaces. We need to take stock of these environmental pressures and ensure that our cities are sustainable into the future.

What is a sustainable city?

A city is sustainable if it can meet the needs of the present without reducing the ability to meet the needs of the future. This means that a sustainable city does not steal from future generations. The meeting of the needs of the present generation must not use up resources that would be used to meet the needs of future generations. This means that there is a responsibility on the present generation to limit waste, to prevent pollution, to maximise conservation and to promote efficiency of resource use. A decision has to be made for a community to remain healthy over the long term and to put strategies in place to make sure that cities will be sustainable well into the future.

World Environment Day

The theme for World Environment Day in 2005 is Green Cities: Plan for the Planet. This highlights the immense impact that cities have on the environment as now more people in the world live in cities than in rural areas. Cities do not sit isolated from the rest of the environment. The resources that they use and the waste they produce affect the surrounding countryside because this is where energy, food and water will need to come from. Air and water pollution do not (of course) stop at the city gates. Some air pollution will even have global effects as in the case of greenhouse gases. Cities and the people in them can only survive in partnership with the natural environment on which they depend. There needs to be a balance struck so that the environment remains healthy enough to support human needs and activities into the future.

Coinciding with this year's World Environment Day, a set of 21 actions have been designed with the specific aim of making cities more ecologically sustainable. These actions include:

• Increasing the use of renewable energy sources and reducing the total amount of energy used
• Reducing the amount of solid wastes going to landfill and improving recycling programs
• Improving the design of buildings so that they are more environmentally friendly
• Reducing the amount of "slum" dwellings within cities
• Conserving the remaining areas of natural habitat within cities
• Improving the access to public transport
• Reducing the amount of vehicle emissions
• Eliminating harmful chemicals from the environment
• Promoting the production of locally grown organic foods
• Ensuring that all residents have access to safe drinking water and sanitation while ensuring that extra water demand is met from sustainable sources

Towns and cities are humanity's home-and its future. Making that a future of peace, dignity and prosperity is the responsibility of all.

Klaus Knoepfer, Executive Director of United Nations Environment Programme

World Environment Day is 5th June 2005