Davos worried about the impact of warming on coastal cities

In terms of impact and probability, this is the third year in a row that they are at the top of the rankings. Risks related to climate change - including those due to lack of action to combat or adapt to it - are emerging as increasingly threatening risks. This is revealed in the report Global Risks Report 2019 ", published as every year before the Davos summit (held in the Swiss Grisons from 22 to 25 January) by the World Economic Forum, organizer of the event.

The year 2018, particularly rich in extreme weather events, helped to raise awareness around the phenomenon. The loss of biodiversity (it is estimated that 60% of wildlife populations have disappeared since 1970) is also becoming more important, especially since its link with climate change is twofold: biodiversity is at once victim, but also helps to amplify it, especially when it reaches the oceans and forests, the main carbon sinks.

The tremendous price of ecosystem services rendered by Nature

Overall, the links between climate change and the economy are becoming more and more apparent. Ecosystem services provided by Nature to the economy (including: drinking water, pollination, natural elements of flood prevention) are estimated at 125,000 billion dollars a year, two-thirds higher than global GDP. Conversely, breaks in production or supply chains have increased in recent years.

Similarly, if the impacts of climate change on the economy could be deleterious, a slow economy, with increasing political tensions, could hinder the investments needed to combat it.

800 million citizens threatened by the rising waters

In this context, one of the most alarming subjects concerns the interaction between galloping urbanization and the rising waters following warming. Indeed, often located on the coast and concentrating population and wealth, cities are particularly vulnerable. It is estimated that 800 million people living in some 570 coastal cities are threatened by a sea level rise of 0.50 meters by 2050.

Whereas between 1901 and 2010, the sea level had risen by 1.7 mm per year on average, between 1993 and 2010 this figure reached 3.2 mm per year. A rise in average temperatures of 2 ° C would generate according to scientists a rise of 0.3 m to 0.93 m by 2100. Some effects are almost impossible to predict accurately. This includes the melting of the Arctic, which would seem much faster than we had expected until recently, and which threatens in the first place the coastal cities of the northern hemisphere.

Globally, 70% of European cities and around 20 African cities with more than 1 million inhabitants are affected by rising water levels. A rise in sea level of 0.9 m by 2100 would threaten 4.3 million people, a figure that would increase to 13.1 million if that rise doubled to 1.8 m over the same period.

Risk of fracture between cities and countryside

And these floods would not only affect housing and businesses, but also public goods and critical infrastructure, which will weigh on taxpayers. The urban concentration is such that, in case of rising waters, 43% of the losses would occur in four cities: Canton, Miami, New York and New Orleans. This would include bridges, the Internet, sanitation and drinking water, and energy infrastructure - some 270 power stations, supplying 450 million people with energy, would be threatened by rising water levels above 0.5 meters.

In spite of these alarming figures, the expenses now spent in repairing the damage caused by these floods are nine times higher than those spent on preventing them.

The authors of the report stress the need for innovative financing solutions and thinking about the distribution of efforts.

On another note, in the face of the growing power of some cities, which may exceed that of some states, the World Economic Forum warns against a trend towards rural desertification accompanied by a slowdown in local economies and a risk on food security.

The authors warn about the risk of growing divide between cities and rural areas, its consequences on electoral volatility and the dynamism of separatist movements ...

That is why they insist on the need for a long-term urban planning and a strengthening of transport and communication networks between cities and surrounding territories.

A diagnosis and tracks that singularly echo the current situation in France ...