On a global scale, some cities are sinking faster than sea levels are rising, says the Global Risks Report 2019, which was produced by World Economic Forum with the support of Guy Carpenter’s parent company, Marsh & McLennan Companies.
Asia will be the worst affected region as a result of a combination of hydrology, population density and asset concentration.
Asia is home to four-fifths of the people who are expected to be flooded if there is a 3°C rise in global temperatures (1). China alone has more than 78 million people in low-elevation cities, a number increasing by 3 percent each year (2).
Relative sea-level rise will be even higher in the many cities that are sinking because of factors that include groundwater extraction and the growing weight of urban sprawl. In Indonesia, for instance, two-thirds of Jakarta’s residents are reliant on groundwater extraction, which is weakening the city’s foundations (3). In parts of Jakarta, ground level has sunk by 2.5 meters in the past decade (4).
Bangkok is low lying and sinking, its natural coastal defenses have been eroded and the nearby Gulf of Thailand is rising faster than the global average (5). Extreme weather patterns are intensifying, leaving the Thai capital vulnerable to rising sea levels from the south and increasingly severe monsoon rains from the north (6).
(1) Holder, J., N. Kommenda, and J. Watts. 2017. “The Three-Degree World: The Cities that Will Be Drowned by Global Warming”. The Guardian. 3 November 2017. https://www.theguardian.com/cities/ng-interactive/2017/nov/03/three-degree-world-citiesdrowned-global-warming
(2) The World Bank and The International Bank for Reconstruction and Development (IBRD). 2010. Cities and Climate Change: An Urgent Agenda. December 2010, Vol. 10. Washington, DC: IBRD and World Bank. http://siteresources.worldbank.org/INTUWM/ Resources/340232-1205330656272/CitiesandClimateChange.pdf
(3) Lei Win, T. 2017. “In Flood-Prone Jakarta, Will ‘Giant Sea Wall’ Plan Sink or Swim?” Reuters. 14 September 2017. https://www.reuters.com/article/us-indonesia-infrastructure-floods/in-flood-prone-jakarta-will-giantsea-wall-plan-sink-or-swim-idUSKCN1BP-0JU
(4) Lin, M. M. and R. Hidayat. 2018. “Jakarta, the Fastest-Sinking City in the World”. BBC.com. 13 August 2018. https://www.bbc.com/news/world-asia-44636934
(5) Sojisuporn, P., G. Wattayakorn, and C. Sangmanee. 2013. “Recent Estimate of Sea-Level Rise in the Gulf of Thailand”. Maejo International Journal of Science and Technology 7 (Special Issue): 106-13. http://www.mijst.mju.ac.th/vol7/S106-113.pdf
(6) Deviller, S. 2018. “With Rising Sea Levels, Bangkok Struggles to Stay Afloat”. Phys.org. 2 September 2018. https://phys.org/news/2018-09-sea-bangkok-strugglesafloat.html