How Rising Sea Levels Are Influencing Migration
Sat, April 10, 2021

How Rising Sea Levels Are Influencing Migration

The continuing rise of sea levels may influence the migration of a large proportion of the population—making sea-level rise (SLR) the most permanent consequence of climate change, according to a new study review / Photo by: Andrii Zhezhera via 123RF

 

The continuing rise of sea levels may influence the migration of a large proportion of the population—making sea-level rise (SLR) the most permanent consequence of climate change, according to a new study review.

SLR-driven migration is multifaceted, influenced by a variety of factors such as environmental hazards, demography, economy, and social factors. The study says it's these factors that may cause people to migrate from SLR-prone areas, especially if it's the only option they have.

The review comes as environmental change becomes the new normal, marked by an increase of attention to commit and act to address climate change, as well as the international reaction to the rising norm.

Populations at Risk

Since 1900, global sea levels have risen by approximately 0.2 meters, and estimates show it will likely continue to rise as climate change ensues. This puts populations near coastal areas at risk, specifically, those living in the low-elevation coastal zone (LECZ), in the 100-year floodplain (the land predicted to flood during a 100-year storm), and populations residing in areas at risk of selected SLR scenarios.

In the US, 40% of the country's total population currently live in coastal communities predicted to achieve continued growth and development. Because of this, the study says SLR and its hazards are projected to threaten between three million and 43 million people will be threatened by 2100—with up to 13 million facing permanent displacement without adequate protection.

Another major SLR hotspot is Bangladesh, putting up to 110 million people at risk of SLR and its associated hazards. The review study cites tidal inundation and storm surge as major hazards, which can "threaten subsistence farmers and fishers living in low-lying delta, interrupting access to freshwater, driving soil salinization and eroding human settlements and arable farmland."

"As 30% of the total cultivatable land of the country lies along the coast, the impacts of salinization on agriculture could undermine food security far beyond the coast and are estimated to displace more than 200,000 people annually," the study adds.

Atoll island nations are also at risk of SLR and its dangers, although they are comparatively fewer compared to those at risk in the US and Bangladesh. Still, SLR forecast is severe for most low-lying nations that the chances of deterritorialization became the focus on the SLR and human migration discourse for many atoll island nations.

Since 1900, global sea levels have risen by approximately 0.2 meters, and estimates show it will likely continue to rise as climate change ensues / Photo by: Steven Heap via 123RF

 

Influences for SLR-Driven Migration

People only have a handful of choices when it comes to escaping SLR-related hazards. While migration is one of those few options, this choice is highly dependent on how the government handles SLR.

These responses are influenced by a combination of environmental and socioeconomic conditions. Responses to SLR will either encourage or discourage people to choose migration as a means to adapt to rising sea levels.

These responses fall into three categories: protection, accommodation, and retreat, the study says. It defines protection and accommodation as "policy actions designed to prevent migration by either reducing SLR hazards (protection) or increasing capacity to cope with the hazard (accommodation)."

In contrast, a retreat is a policy action in which governments directly facilitate migration. This response includes interventions aimed to aid migration out of SLR hazard areas or relocating residents to safer locations.

Relocation is a less desirable response compared to protection and accommodation, but the study notes this adaptive action "is already seen as inevitable for [several] ‘hotspot’ communities now or in the future, when protection and accommodation become too costly or ineffective."

These communities include the Carteret Islands in Papua New Guinea, Vunidogoloa in Fiji, and Kivalina in Alaska, USA—some of which are either undergoing relocation or have relocated due to SLR-related hazards.

Contingent on Today’s Policy Decisions

While SLR will affect millions of people globally, the exact number that will migrate because of this depends on the policy decisions made today.

According to a 2019 paper published in the journal Nature Climate Change, global policy decisions regarding greenhouse gas emissions and a range of other measures about where people live and work in coastal areas will influence whether people would have to migrate and where.

David Wrathall, the paper’s lead author from Oregon State University, said their work demonstrates a new modeling approach on migration due to rising sea levels.

"We’ve been asking how many people will be vulnerable to sea-level rise and assuming the same number of people will migrate," Wrathall said in a press release. "In reality, policies being made today and moving forward will exert a strong influence in shaping migration. People will move in very specific ways because of these policies."

Wrathall and his colleagues said policymakers can't afford to experiment on populations at risk with expensive and possibly dangerous policies as they seek to understand how these decisions influence migration. Instead, they suggest expecting the results of realistic responses using simulations.

The researchers also suggest focussing on global emissions policies under discourse to measure the impact of SLR scenarios on migration.

"All greenhouse gas emissions scenarios have a similar effect on the sea-level rise until about the year 2050, but then sea level rise outcomes really start to diverge. So a first step is modeling sea level rise, policy, and migration in the near term," Wrathall said.

"Modeling allows us to look at all kinds of scenarios to identify the specific policies that might work to help people migrate and anticipate the policies that cause problems."

While SLR will affect millions of people globally, the exact number that will migrate because of this depends on the policy decisions made today / Photo by: Luisa Vallon Fumi via 123RF