Cities and global risks
The events of Port-au-Prince, Benghazi, Abidjan and Fukushima remind us that the history of cities, wars and natural disasters have been intimately linked since the dawn of civilisation. As centres of power and wealth, cities have always been a major driving force of progress: Babylone, Carthage, Rome, Florence… Paris, Vienna, New-York, Shanghai, Port-au-Prince… Two characteristics or urban dynamics – increased population density and the accumulation of wealth and power – have always created or reinforced both natural and political risk factors. The collective memory of humanity is full of images of devastated cities and modified socio-political systems following major destruction in cities: one of the clearest illustrations of this is the history of the Mediterranean, and particularly that of Lebanon.
With the growing urbanization of the planet and the growing number of megacities, the human population is increasingly concentrated in and around cities. There is therefore an urgent need to take a closer look at these “fragile cities”, where more than 50% of the earth’s population already lives.
The co-existence of rapid urbanisation dynamics and natural risk factors: a determining factor of vulnerability
In certain contexts there is heightened vulnerability due to the multiplication of risk factors:
- Urban development in coastal areas and in deltas is a source of major risks. Whether in Africa, Asia, Europe, island systems or the Americas, increased urban density in coastal areas seriously increases the impact of rapid onset disasters (cyclones, tsunami) as well as sensitivity to rising sea levels.
- The location of certain cities in arid zones or the very rapid increase in urban concentration in regions with permanent water shortages are increasingly common phenomena with the decline in living and security conditions in or around numerous desert zones. These dynamics contribute to exacerbating the pressure on water resources and to the increase in health risks linked to serious problems of water quality.
- The location of major conurbations in zones where tectonic risks are high, in both developed and developing countries, is also highly dangerous. This danger can only be reduced by establishing and imposing earthquake resistant standards in construction and by incorporating risk management measures within territorial development policies.
- Urbanisation which increases technological, health and security risks. The concentration of people, and the flow of goods and people are part of the very essence of a city. But, though cities provide numerous economic and social opportunities, they have always been the source of major social upheavals, epidemics and technological disasters.