A new study, published in Frontiers in Marine Science and conducted by researchers from the University of Lausanne, gives yet another reason why we urgently need to combat climate change. One of the key consequences of climate change will be an increase in coastal flooding as relative sea levels rise, according to researchers – something that already happens in some island nations around the globe. 

According to the Intergovernmental Panel on Climate Change (IPCC), even in a low-emissions scenario, sea levels could rise as much as one metre by 2030. 

In the Marshall Islands, for example, “where the highest point is only two metres above sea level, 40% of the buildings in the capital city of Majuro would become permanently submerged”, states an article published in Oceanographic’s Issue 33.

In a sobering assessment, Dr. Eric Rasmussen, the Research Director and Senior Scientist at the Kwajalein Atoll Sustainability Laboratory (KASL), noted: “There has been a global increase of about 1.3°C by 2022 in the temperature average around the world. The Marshall Islands in 2020 were already At 1.5°C, and they were seeing some of the fastest sea level rise of any place on the planet.”

For the new study, the involved researchers analysed various sea-level rise scenarios outlined in the Intergovernmental Panel on Climate Change’s Sixth Assessment Report.

They found that sea level rise ‘is inevitable’ through the 21st century and beyond ‘unless there is appropriate adaptation’ such as global mitigation efforts and proactive planning procedures to address the challenges laid out by the research. For low-lying coastal regions these include land loss, forced migrations and economic burdens.

By investigating coastal flooding to 2100 under the full range of IPCC AR6 (2021) sea level rise scenarios, the researchers found that ‘people living in unprotected coastal areas that are inundated frequently (below 1-in-1 year flood) are assumed to migrate and the land is considered lost’.

They further estimate that between 4 million and 72 million people could migrate over the 21st century, while they believe that a between 2,800km2 to 490,000km2 net land loss could be the result of rising sea levels.

“India and Vietnam consistently show the highest absolute migration, while Small Island Developing States are the most affected when considering relative migration and land loss,” the study reads.

While these figures are alarming, the study argues that protection is the best way to combat these impacts.

The researchers now hope that the new findings will ‘inform national and intergovernmental agencies and organisations on the magnitude of sea level rise impacts and costs and guide assessments of adaptation policies and strategies’. 

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