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.

Typhoon Man-Yi

My brother flew back to Japan yesterday, and his plane should have arrived by now. Typhoon Man-Yi has now made land on the southern island of Kyushu, packing winds of up to 216 km/h (134 mph). That makes it a Category 4 on the Saffir-Simpson scale. Man-Yi is not expected to make it to Tokyo where my brother lives and works until sometime tomorrow morning.

Jeff Masters discusses the Man-Yi news at Wunder Blog and provides live links.

Really cool real-time radar from Japan! I wish that I could read the Japanese, though.

We know that nearly all Atlantic hurricanes begin forming as tropical storms off the coast of Africa. The mechanisms involved are currently being investigated by the NASA African Monsoon Multidisciplinary Analyses (NAMMA) Mission run out of the Cape Verde Islands. National Public Radio had a very interesting "live action" piece on the mission this morning which I am following up here.

The photograph at the top of this blog shows tropical storm Helene, which the researchers happened to catch in her infancy. Helene went on to become a Category 3 hurricane with sustained winds reaching as high as 110 kilometers per hour (70 miles per hour), although she never made landfall due to high pressure conditions over the North American continent. As NPR reporter Jon Hamilton stated at the end of his piece this morning, the NAMMA scientists hope to learn how to spot "Cape Verde hurricanes" like Helene sooner so that people living in areas where hurricane commonly track on land will have more time to prepare.

Some of the "back story" of the mission is missing from the NPR story in that NAMMA has actually been studying African Easterly Waves (AEWs) and Mesoscale Convective Systems over continental western Africa as well as the small cyclones downwind over the Cape Verde Islands. One key atmospheric scientist in the mission, Paul Kucera, has been working in Senegal for at least two years studying rainfall there. Dr. Kucera's colleague at the University of North Dakota, Paul Le Hardy, is also working as a pilot for the mission.

A scientist prominently featured in the NPR story, Robbie Hood, works out of the Marshall Space Flight Center in Huntsville, Alabama. Interestingly enough, she is part Cherokee (1/8th) and descended from the great Cherokee chief John Ross, who led the tribe west on the "Trail of Tears." Other mission participants whom I was able to track down are Bob Pasken, managing the data recorded by the meteorological dropsondes, and Gerry Heymsfield, an expert on cloud radar.