African Cities and Sea Level Rise

This post is stimulated by a recent African Loft post on this same topic. David Wheeler and numerous coauthors with the Center for Global Development (CGD) have compiled the fundamental data. Alexandria in Egypt and Lagos in Nigeria are particularly at risk both because of their likely inundation by rising seas and because of their rapidly increasing populations.

As noted by Gupta and others (2009), "variations in coastal morphology will magnify the effects in some areas, while largely insulating others." Their complete paper projecting storm surge impacts for developing countries can be downloaded at the CGD webpage here. An appended spreadsheet (.xls 53k) further tabulates the data for 327 cities. Alexandria ranks second and Lagos third based upon the population projected to be exposed to storm surges by the year 2100.

Asian cities are also at serious risk, with Manila ranking at the top of the CGD compilation. Cities in Pakistan, India, Bangladesh, Myanmar (Burma), Indonesia, Thailand, and Vietnam are also among the top 20 in the CGD table. Impacts projected for Vietnam's Mekong delta by the CGD and many independent scientists were reported in a recent New York Times article by Seth Mydans.

Wheeler and his coauthors with the CGD are certainly qualified to compile these data and explain their implications for risk assessment and public policy. Wheeler himself stands out as a clear thinker who both comprehends the scientific literature and interprets it to the general public in simple language. Following the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), Wheeler (2007) penned a note about the sea level projections in which he correctly criticized their overly conservative use of glacial ice melting rates for Greenland and West Antarctica. As discussed in an earlier post on African Loft, a scenario in which these ice sheets continue melting at their present rates will in fact result in catastrophic submergence by the year 2099 along the coast of West Africa. Nigeria would be particularly affected because of the dense population in Lagos and other coastal cities.