Cities At Risk Of Rising Sea Levels
The Guardian shared (from research reported in Scientific Reports journal) only this May that ‘small but inevitable rises’ will make coastal flooding around the world even more severe. They predict that many large cities and the small Pacific Islands will experience a doubling of extreme water levels within only 10 years as the Earth continues to warm.
Sea level is rising about 4mm a year because of melting ice caps and water expansion from heat brought about by global warming. But sea rising predictions are becoming direr. In 2013 UN’s Intergovernmental Panel on Climate Change predicted that sea levels will rise between 30cm and 100cm by 2100. But thanks to new monitoring technology and modelling methodologies, these predictions are getting more and more accurate - and recent research is even more pessimistic, predicting rises of 200cm to 300cm by 2100! By 2050, loses from coastal floods are predicted to be up to $1 trillion a year!!
This predicted rise is mind-boggling considering that with just 5cm to 10cm in sea rises, major coastal cities like San Francisco, Mumbai and Abidjan will face double their current risk of coastal floods. The US’ National Oceanic and Atmospheric Administration says that rising sea levels will make rare events much more common. We already see this with the frequency and intensity of hurricanes this hurricane season - Harvey, Irma, Jose and Maria in quick succession and larger impact (than in the past) in the Caribbean’s and US.
But although the US and Caribbean are two areas at high risk of rising sea levels due to global warming, several other countries are in their boat. According to EnviroTech in 2015, the countries at the most risk from sea level rises are mostly in Asia. The top 20 at risk countries are:
China (4% of population at risk, but up to 50.5m people); Vietnam (26% of population at risk, but up to 23% people); Japan (10% of population at risk, but up to 12.8m people); India (1% of population at risk, but up to 12.6m people); Bangladesh (7% of population at risk); Indonesia (4% of population at risk); Thailand (12% of population at risk); Netherlands (47% of population at risk); Philippines (7% of population at risk); Myanmar (9% of population at risk); USA (1% of population at risk); UK (4% of population at risk); Brazil (1% of population at risk); Germany (2% of population at risk); France (2% of population at risk); Malaysia (4% of population at risk); Taiwan (4% of population at risk); South Korea (2% of population at risk); Nigeria (1% of population at risk); and Italy (1% of population at risk).
There is undoubtedly a legion of studies about sea level rise and their impact because of the sheer potential for mass devastation. Adaptation or avoidance will undoubtedly cost a fortune whether governments decide to relocate communities or invest in infrastructure to protect them. But cities have to take matters into their own hands and act accordingly to prevent or minimize the risk to lives and property.
Cities like Rotterdam in the Netherlands can show us some leading practice. With about ¼ of the country below sea level, they have had to take adaptation to sea level rise seriously over the years. They are well known already for the Maeslant storm surge barrier which is capable of holding back the sea in an event of a 10,000-year storm! They are now innovating with the concept of floating communities and floating farms.
Bangladeshi farmers are also experimenting with the floating gardens concept using organic materials – here, farmers grow their vegetables on floating rafts which serve as a base for organic fertilizer and soil. Floating (boat) schools are also being explored and are actually becoming quite common. This has also been experimented with in Nigeria.
Similarly, cities such as Copenhagen have put in place several strategies for varying responses to risk. For example, part of their prevention measures are to expand the capacity of sewers, build dikes, build higher above sea levels and explore ways to manage rainwater. Mitigation measures include early warning systems, building waterproof cellars, having designated areas for rainwater storage, etc. Also, the government now recommends that new buildings have climate adaptation incorporated into their designs (e.g. developing green roofs which can absorb heavy water).
Rising sea levels is now a challenge which no city can ignore because we are already seeing the signs. How cities respond now will be critical to the level of damage they can expect in the next 50 years.