A satellite analysis of night light between 1992 and 2019, conducted in 1,071 coastal regions from 155 countries, shows that 56% of settlements relocated inland, 28% remained in place, and 16% moved closer to the coast. The study, led by Monash University in Australia and published in Nature Climate Change, warns about the unequal adaptive capacity to face sea level rise.
Vulnerability and Inequality: who can move and who cannot
Displacement depends on available resources, leaving poorer communities exposed to higher risks.
“Moving inland only happens where there are means to do so,” explains Wang Xiaoming, lead author of the study. In regions with lower economic capacity, populations remain in vulnerable areas without the possibility of relocation.
In contrast, both rich and poor communities in South America (17.7%) and Asia (17.4%) are moving closer to the coast, driven by economic activities or an excessive confidence in protective infrastructures.
Oceania: Extreme settlements and growing risks
The region hosts some of the closest settlements to the sea, demanding urgent planning.
The study highlights Oceania as one of the regions with greater coastal proximity, making it a critical focus of climate vulnerability. The trend of building near the sea, without considering risks, could widen adaptation gaps and lead to forced migrations in the future.
Causes of Sea Level Rise
Global warming expands oceans and melts glaciers, steadily raising sea levels.
- Thermal expansion: water expands as it warms
- Glacial and polar ice cap melting: releases freshwater that adds to the ocean
- Ozone layer destruction: increases UV radiation and accelerates warming
Environmental, Social, and Economic Consequences
Sea level rise impacts ecosystems, communities, and urban structures
- Flooding and coastal erosion: loss of homes and land
- Saltwater intrusion: contamination of aquifers and agricultural lands
- Biodiversity loss: disappearance of wetlands and mangroves
- Forced migration: millions of people could be displaced
- Island disappearance: territorial loss risk in island nations
- Economic impact: damage to infrastructure, heritage, and economic activities
Future Scenarios: between urgency and uncertainty
Projections from the IPCC and Climate Central warn of rises up to 5 meters by 2300.
According to the IPCC, if CO₂ emissions are reduced and warming is kept below 2°C, sea levels could rise between 20-30 cm by 2050, and between 43-50 cm by 2100.
However, if global efforts fail, massive Antarctic ice melt could raise sea levels between 84 cm and over 2 meters by 2100, and up to 5 meters by 2300, according to Climate Central.
