The world in the 21st century will experience unprecedented urban growth. It was only in 1960 that the first 1 billion people had urbanized. We have since then seen a runaway urban growth. In the 15 years between 2003 and 2018, 1 billion people will have been added to our cities. Most of this growth is occurring in developing regions. In fact, it is predicted that seven out of ten urban dwellers will be African or Asian in 2030.
Beyond being a demographic phenomenon, urbanization is a transformative force that is continually shaping societies, their economies, political systems and environments. Local governments in these regions are facing immense challenges in planning and developing urban infrastructure, and subsequently in providing adequate access to basic services for new and existing urban residents. Moreover, urbanization challenges in the 21st century are unfolding before a multitude of interconnected global challenges, which include:
• Scarcity, depletion and increasing price of energy and other resources
• Increasing destruction of the natural environment
• Climate change
Cities are where most human productive activities are taking place. These activities consume energy and resources and they contribute to climate change and environmental degradation. It is, therefore, self-evident that cities must play a major role in achieving sustainable development in the course of the 21st century. Clearly, our current infrastructure choices will affect city-level sustainability in the medium and long term. The key question linked to the planning and implementation of sustainable urban infrastructure is how cities can provide services, improve quality of life and competitiveness, while making optimal use of energy and resources, minimizing consumption and preserving the environment.