Humans are moving to higher ground, with a global study of 155 countries finding hundreds of coastal settlements already relocating inland to pre-empt future rises in sea levels.
The Monash University-led study analysed decades of satellite nighttime light data across 1071 coastal regions in those countries.
Lead author Professor Xiaoming Wang said it found that human settlements in 56 percent of the regions analysed relocated further inland, 28 percent stayed put, and 16 percent moved closer to the coast.
Professor Wang said relocation was largely driven by vulnerability and the capacity to respond.
“In poorer regions, people may have to be forced to stay exposed to climate risks, either for living or no capacity to move,” he said.
“These communities can face increasingly severe risk in a changing climate.”
Professor Wang said human settlements shifted most towards coastlines in South America (up to 17.7 percent) and Asia (17.4 percent), followed by Europe (14.8 percent), Oceania (13.8 percent), Africa (12.4 percent) and North America (8.8 percent).
He said Oceania had some of the closest settlements to the coast globally, reflecting the region’s reliance on coastal economies.
“In Oceania, we see a common reality where wealthier and poorer communities are both likely to relocate towards coastlines in addition to moving inland.
“On one hand, the movement closer to coastlines can expose vulnerable populations to the impacts of storms, erosion, and sea-level rise. On the other hand, it can expose those wealthy communities to the growing coastal hazards.”
Professor Wang said the study also highlighted concerns that overconfidence in protective infrastructure encouraged risky development close to the coast.
“It is interesting to note that high-income groups also had a relatively higher likelihood to remain on coastlines, such as in Europe and North America.
“This can be due to their capacity and wealth accumulated in coastal areas.”
He said the study warned that relocation inland may become unavoidable as sea levels rose and climate change intensified.
“Relocating away from the coast must be part of a long-term climate strategy, and the rationale for policy and planning to relocate people requires meticulous consideration of both economic and social implications across individuals, communities and regions.
“Alongside climate change mitigation, it needs to be combined with efforts to reduce coastal hazard exposure and vulnerability, improve informal settlements, balance coastal risks with livelihoods and maintain sustainable lifestyles in the long-term.
“Without this, coastal adaptation gaps will continue to be widened and leave the world’s poorest behind.”
Read the full study: Global coastal human settlement retreat driven by vulnerability to coastal climate hazards.
