Climate change to cause mass migration
Rising sea levels will be to blame, says an American professor of marine science. But he believes that it could also present an opportunity to build more sustainable cities.
Michael Orbach, professor of the practice of marine affairs and policy at Duke University’s Marine Lab, says that we will see a sea level rise of between one and two metres within a century. This does not bode well for the 20 of the world’s 30 ‘megacities’ – those with a population of more than eight million – that are located in low-lying coastal areas. These include London, San Francisco, Rio and Mumbai.
“Several billion people and their infrastructure will be moving,” Orbach states. “We will not, in the end, try to defend many locations because of the cost and the practical difficulties.”
He believes that defences similar to the Thames Barrier will be possible in some locations, primarily major urban areas, but even those will become increasingly costly and less feasible as the sea level rises above two metres.
The natural infrastructure will be affected, too, with coastal features such as mangrove swamps, coastal marshes and fringe swamps and forests being submerged. “All of these have historically migrated with changing sea levels,” says Orbach, “but now there is human infrastructure in the way.”
There is a silver lining, however, despite the looming problem of what to do with the infrastructure that is left behind. “It will be a fabulous opportunity to design and build new, more sustainable built environments,” he says.