Dive Brief:
- Rising sea levels will severely impact nearly triple the number of people previously estimated to be affected, according to a new study published in the journal Nature Communications and co-authored by the CEO of Climate Central. The data suggests coastal flooding (at least once per year) will reach levels where 300 million people currently live, and more than 150 million people live in locations that could be permanently inundated by 2050.
- Climate Central's interactive map that accompanies the study shows old projections compared with the expanded risk areas. The map indicates that whole cities could be inundated; in the United States, for example, most of New Orleans and large portions of New York are among the numerous communities shown to be underwater or prone to frequent, severe flooding by 2050.
- The areas of most concern are concentrated in developing countries in Asia. More than 70% of the world's population currently living on implicated land are in just eight Asian countries: Bangladesh, China, India, Indonesia, Japan, the Philippines, Thailand and Vietnam. However, the increased flood risk touches every continent.
Dive Insight:
Coastal communities worldwide must prepare for more difficult times than previously anticipated, according to the study. Cities with dense populations like New York and Mumbai are projected to experience serious flooding impacts if no actions are taken to prevent the negative consequences. Flooding effects are projected to be widespread, but major global cities could experience particularly harsh consequences that carry to other areas.
Jakarta, Indonesia, is a city projected to face large swaths of permanent inundation. The city has long been known to be sinking, in part due to land management decisions, exacerbating flooding caused by rising sea levels. The Indonesian president announced this year that the multi-island nation's capital would move from Jakarta to a new location on the island of Borneo. Moving an entire governmental hub to an area known for its beaches and rainforests undoubtedly will turn out to be no small feat.
Coastal flooding reportedly will have profound economic and political implications for the affected countries, which could have a ripple effect on other countries. The expense of relocating people away from rising waters — such as the Jakarta case, or otherwise — is incredibly expensive both for citizens and governments. New infrastructures must be built and others reinforced to support an influx of citizens moving to a new area in a short amount of time.
Besides everyday infrastructure such as transportation, utilities or buildings, coastal cities will need to reconsider the integrity of their flood prevention infrastructure. The study suggests that levees, seawalls and other preventative measures already in place will need to be expanded to cover more territory as sea levels rise. In addition, existing coastal infrastructure likely will not protect against the enhanced threats without continued maintenance and upgrades.
"[E]ven in the US, sea-level rise this century may induce large-scale migration away from unprotected coastlines, redistributing population density across the country and putting great pressure on inland areas," the study says.
Beyond the raw expense of moving populations away from a coast, the study warns against social and political instability. Historically, conflict erupts in areas that experience a large-scale migration, especially in resource-constrained areas. The study recommends further research should be performed on the timing, locations and intensity of global migrations related to flooding.
