Rising sea levels driven by climate change could inundate habitats for more than 40% of the world’s land vertebrates by the end of the century, according to new research published in Science and reported by Mongabay.
The global study overlaid habitat suitability maps for 34,120 land vertebrates—covering roughly 90% of all known amphibian, reptile, bird, and mammal species—with sea level rise projections across five Intergovernmental Panel on Climate Change (IPCC) emission scenarios.
Depending on the emissions trajectory, between 14,325 and 15,324 species will face coastal habitat loss by 2100. Yet only 5.9% of these exposed species are currently classified as at risk from climate change on their IUCN Red List assessments.
Reptiles, narrow-ranging species, and already threatened animals face the highest vulnerability. The study found that reptiles will experience nearly double the amount of habitat loss seen in birds or mammals. Under high-emissions pathways, the number of species projected to lose more than 10% of their available habitat jumps from just 18 species in 2050 to 109 species by the end of the century, with reptiles making up more than half of that group.
Three specific animals—the Catalina chuckwalla (Sauromalus klauberi), the Restinga toadlet (Melanophryniscus setiba), and a Brazilian worm lizard (Amphisbaena littoralis)—are projected to lose over half of their global habitat to rising seas by 2100. Overall, up to 63% of birds, 52% of mammals, 36% of reptiles, and 24% of amphibians will experience some level of coastal inundation.
“Conservation planning needs to consider not only where species occur today, but also which parts of their habitat are projected to remain above water in the future,” co-author Zhong-Wen Jiang, a postdoctoral researcher at Sun Yat-sen University, told Mongabay in an email.
Geographically, the Amazon River delta and Southeast Asia will suffer the most severe disruptions. The Amazon delta faces extensive inundation due to its rich biological diversity, with more than 100,000 hectares of riparian forests and coastal wetlands expected to go underwater by 2050.
Meanwhile, Southeast Asia hosts numerous range-restricted species concentrated along vulnerable coastlines. Inundated habitats across Peninsular Malaysia, Borneo, and Sumatra support nearly three times as many threatened species as the rest of the world, according to the research.
The study also identified critical “refugia” habitats that are projected to avoid future flooding, offering species a chance to adapt. However, 96% of these vital refugia lie outside of existing protected areas, revealing a major blind spot in current conservation frameworks.
In 2016, scientists officially declared the Bramble Cay melomys (Melomys rubicola) extinct after rising waters completely inundated its tiny coral islet home in the Torres Strait, marking the first recorded mammalian extinction driven directly by human-caused sea level rise. Across Europe, coastal shorebirds are experiencing population crunches as rising seas squeeze them against fixed human infrastructure like seawalls and dykes, a phenomenon documented in recent research published in Nature Climate Change.
In the Bangladesh Sundarbans, rising tides threaten to submerge the majority of the mangrove habitat relied upon by the endangered Bengal tiger, as detailed in work published in the Science of The Total Environment. These compounding pressures point to a broader reality: the true impact on terrestrial wildlife will likely exceed baseline estimates once factoring in intensifying storm surges, creeping salt spray, and escalating coastal development.
“We should not wait until habitats are inundated to decide how to protect the species that depend on them,” Jiang told Mongabay, emphasizing the necessity of early, internationally coordinated mitigation.
