Are our cities just too big to flood ?

This was the question asked on the the Yale Environment 360 blog and I believe the timing is perfect as last year cities such as New York City, Manila and Bangkok got it by record floods. Now it is the turn of Jakarta.

The capital megacity of Indonesia now has water in its streets and people to evacuate because of another flood. Given that rising temperatures mean rising sea levels and more extreme weather, the threat is huge.

First in terms of people – as the majority of people will live in cities in 2050 and as 14 of the world’s 17 largest cities are located along coasts.

Second, in economic terms, the threat is even bigger as the Yale Environment 360 blog reports. Indeed, trillion of dollars of assets and infrastructures would be at risk and the multi billion costs of Sandy will most likely look like a mere trifle.

Here is an extract of the article :

Just as banks grew “too big to fail,” over the next half-century these coastal megacities may grow “too big to flood.” But flood they will unless they dramatically revise their growth strategies and undertake major infrastructure projects designed to protect them from the dual threat of rising sea levels and intensifying storms, experts say.

Based on the conservative assumption that sea levels will rise by only 18 inches by 2070, the OECD finds that total assets vulnerable to flooding and storm surges of just 10 of these cities could account for some 9 percent of the world’s GDP.

But many climate scientists and coastal experts note that sea level rise forecasts by groups such as the Intergovernmental Panel on Climate Change did not factor in the melting of the Greenland and Antarctic ice sheets.

When they are taken into account, these experts say that global sea levels could well rise 3 to 6 feet this century, leaving scores of cities and massive amounts of economic infrastructure dangerously exposed.

I delved on that very topic in a series of article all the way back to 2008 and in another post in 2011. All this makes it all too clear : let’s tackle climate change or it will tackle us…