Introduction Introduction Chapter 5 Chapter 5
Chapter 1 Chapter 1 Chapter 6 Chapter 6
Chapter 2 Chapter 2 Notes for Indicators Notes
Chapter 3 Chapter 3 Notes for boxes Notes for boxes
Chapter 4 Chapter 4 Indicators Indicators
CHAPTER 5 Printer Friendly printer friendly version
Chapter 1 Urbanization and Sustainability in the 21st Century

Cities: Burden or Blessing?

Taking the Broader View

Looking Beyond the Local

Land Cover Changes

Cities and Climate Change

Poverty and Vulnerability to Natural Disasters

Sea Level Rise: Not If but When, and How Much?

Adapting to Climate Change

Local Actions, Global Consequences: Global Change, Local Impact

Taking the Broader View

People are already doing a great deal at the local level to make urban locations more habitable and environmentally friendly.(3)Cities can learn from each other and use positive experiences for their own benefit. However, finding local solutions to current problems is not enough, given the rapid doubling of the urban population of developing countries in an era of economic globalization. Local strategies will have to be integrated into a more inclusive temporal and spatial framework to address broader problems and ensure longer-term sustainability.

The concept of global environmental change (GEC) provides such a framework. GEC is the sum of a range of local, national or regional environmental challenges.(4)GEC also denotes the impacts of these challenges, for example, changes in temperature and precipitation regimes that could increase the frequency of floods and droughts, raise sea levels or influence the spread of diseases and invasive species.

Urban areas both contribute to GEC, through the consumption of resources, land use and production of waste, and suffer its impacts. The full consequences of GEC will be felt only in the medium to long term. Because of this time lag, they are often ignored in favour of more immediately pressing environmental problems such as water supply, sanitation and waste disposal.

Yet policymakers must be aware that their local decisions have far-reaching effects and conversely that climatic or ecosystem changes may have a local impact. Both aspects require better information and a longer-term vision. Decisions being made today about energy sources, transportation systems and spatial planning will have a long-term impact on the regional and global biophysical processes that contribute to GEC. Solving current problems can help mitigate the impacts of GEC—but only if the interactions between local urban problems and regional and global processes are explicitly considered.

Such integrated thinking and planning can increase the resilience of urban areas to GEC-related shocks. For example, it can help to preserve healthy ecosystems or to ensure that new transportation, water supply and energy systems are built to withstand climate-related hazards. Conversely, actions aimed at long-term global issues may contribute to solving more immediate and local environmental problems.