We humans certainly don’t make it easy for ourselves. In yet another example of the dangers of civilization, a coastal megacities around the world are sinking, often much faster than the sea is rising to meet them, according to a new study. The BBC reports:
In some parts of the globe, the ground is going down 10 times faster than the water is rising, with the causes very often being driven by human activity. […]Gilles Erkens from the Deltares Research Institute, in Utrecht, in the Netherlands, said parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal urban settlements would sink below sea level unless action was taken. […] “Land subsidence and sea level rise are both happening, and they are both contributing to the same problem – larger and longer floods, and bigger inundation depth of floods,” Dr Erkens told BBC News.
Plate tectonics account for some of the subsidence in places like Venice, but researchers say human activity is contributing to this sinking at a much greater rate. Pumping groundwater for human consumption leaves behind empty space, and the earth on top sinks to fill it. Tokyo has sunk more than six feet in recent years as a direct result of such practices. Venice, perhaps the city most famous for battling the sea, has also sunk over the past century as the result of artesian well drilling. Finding water for these megacities is no easy task, and often they have no choice but to get it from somewhere else. As one expert put it, “Tokyo did that and subsidence more or less stopped, and in Venice, too, they have done that.”Rising sea levels get plenty of attention from the media, mostly in the context of climate change. But subsidence, admittedly another man-made problem, seems at the moment to be far more urgent.