The scientific consensus is that a 1.5°C increase in global temperature will generate a global sea-level rise of between 1.7 and 3.2 feet by 2100. While some coastal cities and nations will literally disappear, the rest will need to adapt, and quickly.
Asian cities will be particularly badly affected. About four out of every five people impacted by sea-level rise by 2050 will live in East or South East Asia. Cities such as India, Bangladesh, Vietnam and Egypt will have to face one of the worst impacts of the climate disaster as they are ranked in the top 10 countries exposed to coastal flooding. Rise of sea levels in coastal cities will threaten the coastal plant life, wildlife population and any clean underground water sources. Although sea levels will not rise instantaneously, the calculated increases will be “locked in” at a temperature rise of 3C, meaning they will be irreversible even if warming eventually slows down. At least 275 million city dwellers live in vulnerable areas, the majority of them in Asian coastal megacities and industrial hubs such as Shanghai, Shenzhen, Bangkok and Tokyo
CAUSES
glaciers and ice sheets worldwide are melting and adding water to the ocean.
the volume of the ocean is expanding as the water warms.
decline in the amount of liquid water on land—aquifers, lakes and reservoirs, rivers, soil moisture. This shift of liquid water from land to ocean is largely due to groundwater pumping.
IMPACTS
rising seas threaten infrastructure necessary for local jobs and regional industries.
Roads, bridges, subways, water supplies, oil and gas wells, power plants, sewage treatment plants, landfills—the list is practically endless—are all at risk from sea level rise.
rising sea level creates stress on coastal ecosystems that provide recreation, protection from storms, and habitat for fish and wildlife, including commercially valuable fisheries. As seas rise, saltwater is also contaminating freshwater aquifers, many of which sustain municipal and agricultural water supplies and natural ecosystems.
WORST AFFECTED CITIES:
Osaka, Japan
the swaths of Osaka – the commercial heart of a region whose GDP is almost as big as that of the Netherlands – would disappear beneath the water, threatening the local economy and almost a third of the region’s 19 million residents.
Shanghai, China
When it comes to flooding, the coastal city is one of the world’s most vulnerable. Now one of the world’s biggest ports, the former fishing village is bordered by the Yangtze river in the north and divided through the middle by the Huangpu river. These water bodies further increase both the risk and danger of flooding.
Since 2012, the government has been making steady inroads to tackle the threat, including building China’s largest deepwater drainage system beneath the Suzhou Creek waterway, made up of 15km of pipes to drain rainwater across a 58 sq km area.
Miami, U.S.
Few other cities in the world have as much to lose from rising sea levels as Miami, with each successive “king tide” that overwhelms coastal defences and sends knee-deep seawater coursing through downtown streets the alarm bells ring louder.
A sense of urgency is evident when commissioners ask voters to approve a “Miami Forever” bond in the November ballot that includes $192m for upgrading pump stations, improving drainage and raising sea walls.
Data from the Climate Central group of scientists analysed by Guardian journalists shows that 3C of global warming would ultimately lock in irreversible sea-level rises of perhaps two metres. Cities from Shanghai to Alexandria, and Rio to Osaka are among the worst affected. Miami would be inundated - as would the entire bottom third of the US state of Florida.
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