Today, coastal cities account for two-thirds of the planet’s megapolises and represent an increasingly large proportion of the population and human activity.
These cities will be the first to confront the effects of climate change on the oceans, as the sea level rises in the coming decades, and they will have to become more resilient to increasingly frequent extreme weather conditions. A new form of urban planning appears: after the green city, here comes the blue city. Usbek & Rica (1), the media that explores the future, takes a look at these challenges and emerging trends.
Are cities moving to the seaside? The coast has always been conducive to the development of cities, but this trend has gathered pace in recent decades, and shows no sign of slowing down.
In 2009, 67% of conurbations of more than 10 million inhabitants worldwide were located on the coast, and these mega-cities are expected to reach 80 million inhabitants by 2030. All over the planet, the growth of coastal urban zones is outstripping that of other cities.
Rising sea levels, monsoons and hurricanes
Coastal cities are becoming increasingly dense, populated and powerful, and increasingly fragile too. From New York to Manilla, Lagos and Copenhagen, seaside cities of all sizes are amongst the habitats that are most exposed to the consequences of global warming, precisely because they are close to the oceans. Flooding and rising water levels alone could cost almost $1,000 billion per year in 2050, if no measures are taken, according to a recent report by the World Bank.
Global warming will increase the frequency of other events in other parts of the world, such as monsoons, cyclones and hurricanes. These events present all the major functions of coastal cities with huge challenges: housing, public spaces, energy, transport, health and drinking water systems, etc. The lowest urban zones will be faced with the rise in the level of the water, which could engulf entire districts. Cities in China (Shanghai), India (Calcutta) and South-East Asia (Jakarta) are under the greatest threat, but forecasts of the rise in the sea level have shown that, if greenhouse gas emissions continue at the current rate, New York, Tokyo, Miami, London and Rotterdam could also be impacted in a century or two, according to a study by the Climate Central think tank.
Flee seaside cities, or reinvent them?
Leaving the coast to move inland is an increasingly common idea, exposed in the reports of the GIEC, in the columns of the New York Times or even by engineering consultancies. But on the other hand, new utopians suggest to take the head by building offshore cities, as shown by the projects for floating cities of the Seasteading Institute in the United States, or Aequorea, the futuristic concept devised by the Belgian architect Vincent Callebaut: a huge nautical and subaquatic structure printed in 3D from algae and plastic waste from the ocean
Other alternatives are emerging to adapt cities to this new situation. In 2014, the ONE Prize Award architectural contest asked the entrants to work on the concept of storm-proof cities, a proof among others that architects, designers and local communities are now fully committed to creating seaside towns that respect the coastal environment and are resilient to assaults by the oceans. Certain coastal mega-cities, such as Miami, even have their own Chief Resilience Officers.
In the United States again, groups of architects are working with local communities to co-design public spaces, buildings, energy systems and drinking water systems, following the damages caused by hurricane Sandy, with the goal to reduce their vulnerability and to enable them to survive such events. One example is the Resilient Long Island operation, a precursor of the adaptability of the coastal cities of the future. In Rotterdam, where much of the city is below sea level, the city authorities are looking into the creation of water plazas, or public parks capable of absorbing and retaining water in the event of a flood, thereby protecting the city centre.
Disasters can also be countered by using the capacities of nature. The city of Padang on Sumatra is currently hosting Kogami, a “coral forest” project designed by the architect Ben Devereau. By stimulating the development of coral reefs on recycled containers immersed in the sea, the city will be able to reduce the force of tsunamis.
The combination of these increasingly numerous initiatives gives rise to the idea of a blue urbanism, which is the essential companion of the green urbanism of sustainable development. As cities all over the world become major players in the fight against climate change, coastal cities could well pioneer the reinvention of our relationship with the oceans and the natural world.
This article was published in the third issue of open_resource magazine : «The oceans, future of the blue planet»
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