As sea levels rise, these cities are most at risk, report says
David Wagman | March 03, 2020Two coastal cities that are at the heart of one of China's manufacturing hubs are the most vulnerable in the world to the threat of sea level rises, according to a new report.
Guangzhou and Dongguan, two major cities in China’s Pearl River Delta Economic Zone, are part of a manufacturing hub that generates 20% of Chinese GDP.
The threat assessment was conducted by consultancy Verisk Maplecroft for its Sea Level Rise Index.
Analysts used the index to assess sea level rise exposure of 500 cities with million-plus populations and found that 11 of the 15 most at-risk cities are in Asia. In addition to Guangzhou and Dongguan, Tokyo, Jakarta, Ho Chi Minh City and Shanghai also are included on the list. Among the most prominent cities outside of Asia facing the highest risk are Dubai, Alexandria and New York.
It said that globally, more than a quarter of the 29 million people directly threatened by sea level rises are in China.
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The report quoted the Intergovernmental Panel on Climate Change (IPCC), which reported in 2019 that rates of sea level rise have reached 3.6 mm per year and are speeding up. The report said that by 2100, the world could experience seas between 30 cm and 110 cm higher, depending on global emissions. If carbon emissions grow in line with the IPCC’s high emission scenario, then a 60 cm to 110 cm rise could result.
In addition to Guangzhou and Dongguan, Tokyo, Jakarta, Ho Chi Minh City and Shanghai also are included on the list. Among the most prominent cities outside of Asia facing the highest risk are Dubai, Alexandria and New York. Source: Verisk MaplecroftIndustrial center
The Pearl River Delta Economic Zone includes some 120 million people and generates 3.8% of global wealth. The region includes much of China’s automotive, petrochemical and electronics industries and is integral to global supply chains.
However, the report says that like all deltas, it is low-lying, leaving around one-fifth of Guangzhou’s urban area classified as high or extreme risk in the Sea Level Rise Index. Although more than 3,000 km of sea defenses exist in the Pearl River Delta, a 30 cm rise in global sea level "would overwhelm many of them," the report said.
Coastal flooding in 1998 caused around $20 billion in damage across the region, the report said. It warned that rising sea levels "will amplify that damage as flooding, typhoons, heavy rain and storm surges pound its cities more frequently." And although Guangzhou is transitioning toward a more diverse economic mix, with a greater contribution from financial services, its core economic manufacturing activities are not easily relocated and have long investment cycles.
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Infrastructure investment
The report said that efforts to counter sea level rise will involve large public investment. In March 2019, New York (ranked the 14th highest risk city globally) announced $10 billion of flood defense infrastructure spending.
Although Guangzhou is transitioning toward a more diverse economic mix, with a greater contribution from financial services, its core economic manufacturing activities are not easily relocated and have long investment cycles. Source: Wikimedia Commons by jiang-wen-jieIn late 2018, New Jersey officials approved the alignment of a $230 million flood-control system to better protect cities impacted by Superstorm Sandy. The flood-resistant system is intended to protect Hoboken and parts of Weehawken and Jersey City from flooding that often accompanies storms and other weather events. Construction is expected to begin in 2020 to meet a federally mandated completion date of 2023.
London, ranked 32nd in terms of risk in the index, is protected by the Thames Barrier, which was designed to cope with an 8 mm per year rise in sea levels. Under current projections, a new barrier will be required before 2070, at an estimated cost of $9 billion.
Indonesia, meanwhile, is moving its capital, Jakarta, which is sinking toward current sea level as the aquifers it sits above are drained.
The Verisk Maplecroft report said that many nations should have the ability to organize and finance resilience measures. But for at-risk cities in India, North Africa and Southeast Asia, the costs "will be out of reach."
For lower-income nations, reacting to rising sea levels will take time and investment, drawing funding away from other development priorities. The report said that failing to prepare for sea level rise will also impact a country’s investment potential and credit risk, making it more difficult to fund projects.
