More than 570 cities will be exposed to the risk of rising sea levels, according to the C40 network of global cities collectively addressing climate change. The organization estimates that the economic cost of submerged and storm-ravaged communities could be $1 trillion. Many coastal communities around the world already live with the threat from sea level rise and coastal flooding.
C40 has stated that ff the world fails to commit to the Paris Agreement’s goal of reducing carbon emissions and limit global average temperature rise to 1.5 degree Celsius, many of the world’s cities will face an extraordinary threat from rising seas and coastal flooding by mid-century.
Estimates suggest that the global economic costs to cities, from rising seas and inland flooding, could amount to $1 trillion by mid-century. As with other climate hazards, local factors mean that cities will experience sea level rise at different paces. Cities on the east coast of the U.S., including New York City and Miami, are particularly vulnerable, along with major cities in South East Asia, such as Bangkok and Shanghai.
In the US, east coast cities are witnessing sea level rise that is two to three times faster than the global average while cities along China’s Yellow River Delta are experiencing sea level rise of more than 22 cm (9 inches) per year. Miami, Guangzhou, and New York are the top three cities in terms of the value of assets exposed to coastal flooding between 2010 and 2070, according to a 2016 report by Christian Aid; between 2 and 3.5 trillion dollars. But it’s Kolkata, Mumbai and Dhaka that have the highest number of people at risk from coastal inundation; between 11 and 14 million.
Even though variations in geography leave certain cities acutely exposed to sea level rise and coastal flooding, such as low-lying delta cities in typhoon and hurricane zones, a city’s level of climate risk is intensified by socio-economic circumstances and the built environment’s shape and form. In New York City, some of the most valuable properties in the world are located in flood-prone areas at the southern tip of Manhattan and real estate valued at an estimated $129 billion lies within the city’s floodplains.
When Hurricane Sandy struck New York in 2012, coastal floods impacted an estimated 90,000 buildings in New York City alone, while 2 million people lost power, which caused extensive damage, disrupted commercial activity and costed the city over $19 billion. When the waters seeped in over Manhattan, metro stations were flooded and electrical substations submerged, which impacted critical services such as hospitals; several of which had to be evacuated.
“The hurricane exacerbated the challenges across the city, whether it would be inadequate infrastructure, lack of affordable housing, or existing environmental hazards.” said Jainey Bavishi, New York City’s Director of Recovery and Resiliency
While the financial scale of a storm surge impact may be unique in New York, considering the city’s property values and status as a global financial centre, many other cities are dealing with a common problem: How can a city increase its resilience to climate change while simultaneously meeting the housing demands of a rapidly growing, low-income population?
The carbon-neutral Floating Office Rotterdam (FOR) was created for a future in which rising sea levels caused by climate change are expected to bring more frequent and severe floods. Moored at Rijnhaven port in Rotterdam, the floating office for the Global Center on Adaptation is a building for a new age. Off grid and carbon-neutral, it floats – rather than flood – if water levels rise due to climate change. Fun as well as functional, it also forms a key element in a newly redeveloped port environment by providing public waterside space – and even a swimming pool.
Opened in September by King Willem-Alexander of the Netherlands, FOR is one of a number of buildings that have been redesigned to exist on the water in anticipation of rising sea levels, floods and land loss.
FOR’s pontoons provide a stable floating foundation that enables the structure to move as water levels rise and fall. Renewable energy is drawn from huge solar panels above and beneath the water. A plant-filled roof leads to overhanging balconies that cool the interior and construction materials were chosen because they can be easily recycled when the building is no longer needed.
The project is supported by former United Nations Secretary-General Ban Ki-moon as well as International Monetary Fund Managing Director Kristalina Georgieva.
