The well-known Brundtland report of 1987, Our common future, has been a milestone in the evolution of sustainable development thinking. In it, this ideal is defined as a “development that meets the needs of the present without compromising the ability of future generations to meet their own needs”. The interest in this issue is of course linked to the international realization that the modern world is not developing sustainably. This has become painfully clear during the past few years in particular. The climate is changing because the global population is drastically increasing the natural greenhouse effect. Raw materials such as oil, coal and gas are getting more and more expensive as they become scarcer, partly due to the enormous demand from China, India and other parts of the world that are undergoing rapid economic development. It is also becoming increasingly difficult to meet the growing and to some extent more prosperous global population’s demand for food.

Sustainable development – a desire rather than a trend – can be broadly interpreted: one may rightly wonder whether the development of the world is ‘sustainable’ in a political, social, economic or cultural sense. However, here we shall confine ourselves to sustainability in the stricter sense: the relation between humanity and the earth it inhabits. Think for instance of the climatological conditions, the reserves of natural resources and biodiversity.

Orientation towards sustainable development issues is an essential part of global citizenship education. The major issues involved affect the survival of all human beings. Moreover, sustainability-related thinking and acting brings up the question of fundamental values: solidarity (both with other earth dwellers in the past as well as with future generations), a harmonious and respectful relationship between man and nature, and reflection on a responsible lifestyle.

Which technological innovations, adaptations to one’s personal lifestyle and forms of international cooperation are required to make the transition to a more sustainable world? A knowledge base is also necessary to achieve adequate insight into the factors determining sustainable development: from population growth to sound natural resource extraction, from international policy to technological innovation.

Three aspects have been selected to illustrate the theme of sustainable development:

• Population growth and urbanization in relation to the availability of natural resources, environmental quality and prospects for a more sustainable development. Window chosen: Mexico City.
• The availability of strategic natural resources such as fresh water, agricultural land or energy sources, and the opportunities for better distribution of scarce resources. Window chosen: drinking water in the Middle East.
• Climate change, the international policy to reduce its speed, the necessary adaptation to climate change and the consequences for various parts of the Earth. Window chosen: the North Pole.