A new study uncovers that Small Island Developing States, contributing the least to climate change, bear disproportionate flood risks. Findings highlight urgent need for action in mitigating and adapting to climate impacts.
A new study led by the University of Bristol has made a startling revelation: inhabitants of the world’s smallest and least polluting countries, known as Small Island Developing States (SIDS), are facing severe flooding risks due to climate change. The research, published in Environmental Research Letters, highlights an urgent need for global action to help these vulnerable nations adapt and mitigate the devastating impacts.
Small Island Developing States, scattered across the Pacific, Caribbean, Indian Ocean and the South China Sea, contribute minimally to global carbon emissions. Despite this, their populations are bearing the brunt of climate-driven flooding risks.
The study reveals that nearly one in five people in SIDS, approximately 8.5 million individuals, are currently exposed to coastal and inland flooding.
In some SIDS, such as the Bahamas, Guyana and Tuvalu, this proportion skyrockets to over 60%, the study found. This stark contrast sheds light on the imbalances and injustices wrought by climate change, where those least responsible suffer the most.
Lead author Leanne Archer, a research associate at the University of Bristol’s Cabot Institute for the Environment, emphasized the urgency of the situation.
“Flooding is now an alarming real-world threat for so many people globally,” she said in a news release. “This study demonstrates that the often-overlooked Small Island Developing States are already subject to a disproportionate level of flood exposure, despite contributing the least to climate change.”
Projections from the study paint a grim picture for the future. Even under the most optimistic global warming scenarios, the number of people in SIDS affected by rising sea levels, storm surges and extreme rainfall is set to increase significantly.
For context, the study compares the projected impact in SIDS to that in developed nations like the United States and UK where 13% and 8% of the populations, respectively, are impacted by flooding.
“The findings should be a call to action to support these nations in adapting to and mitigating against these extreme repercussions, even under the lowest emissions scenario, which put life and livelihoods in peril,” Archer added
SIDS, identified by the United Nations for their exceptional vulnerability to climate effects, generally have small populations ranging from about 1,000 to 7 million people. Coastal flooding poses a significant threat due to the concentrated coastal habitations in these regions. However, the study revealed that inland flooding is a considerable issue, contributing to 81% of overall flood exposure.
Previous studies had largely overlooked inland flooding, leading to a significant underestimation of the risks faced by SIDS.
Archer highlighted this gap, adding, “Previous studies have only focused on coastal flooding, representing a significant underestimation of exposure. This is also the very first time a comprehensive picture of flood risk has been mapped across all 57 Small Island Developing States because the populations are so small, they haven’t met the minimum catchment size of previous major global studies.”
In collaboration with the University of Southampton and using high-resolution flood models from Fathom, a water risk intelligence firm, the research provided compelling evidence. Even with global warming limited to a 1.5 degrees Celsius increase by 2100, over a fifth of SIDS populations will face flooding. In more dire scenarios, this figure could rise to nearly a quarter. The UN has warned that without more aggressive carbon reduction efforts, the world could face 3.1 degrees Celsius warming.
Co-author Paul Bates, a professor of hydrology at the University of Bristol and co-founder of Fathom, emphasized the significance of the research.
“This study fills an important gap in research, including direct measures of flood hazard and exposure which are essential to adequately reduce loss and damage from flooding in the Small Island Developing States,” he said in the news release.
This study underscores the immediate need for strong climate policy and action to support those most vulnerable to climate impacts. The findings serve as a timely warning that the world’s political leaders and policymakers must back global commitments with meaningful actions to reduce carbon emissions and mitigate flood risks.