What are the health impacts of sea-level rise, and who should pay?
The director general of India’s Centre for Science and Environment, Sunita Narain, said: “It is clear that women are disproportionately hit … The increased frequency and intensity of these weather events puts pressure on livelihoods and this means that the men are the first to migrate in search of work. “This then puts additional pressure on women to cope and indeed survive.” In November in Solomon Islands, the former Tongan health minister, Dr Saia Ma’u Piukala, stood outside the main hospital in Honiara and “watched seawater lapping at its outer walls.” “The facility is now under threat, with plans under way to relocate it to higher ground — a massive and costly undertaking,” Saia, a surgeon and now the World Health Organization’s regional director for the western Pacific, tells the Guardian. “It should never have come to this.” The impact on patients and health services is just one part of a growing health burden driven by sea-level rise, including water contamination, infectious disease, food insecurity, displacement and worsening mental health. In 2024, at the inaugural UN General Assembly meeting on sea-level rise, representatives of small island developing states and low-lying countries described the issue as a global crisis threatening one billion people worldwide, urging governments globally to act to protect their health and lives. “We contributed almost nothing to this global scourge, but it is our land that is being consumed by the sea,” Samoa’s then prime minister, Afioga Fiamē Naomi Mataʻafa, told the meeting. The result is a Lancet Commission on sea-level rise health and justice, co-chaired by the leading climate negotiator Christiana Figueres and enlisting almost two dozen health and environment experts as commissioners — Saia among them. One of the most difficult questions the commission will grapple with is this: who should be responsible for paying when cities like Honiara are forced to rebuild critical infrastructure due to the impacts of some of the most polluting corporations and countries? In 14 Pacific island countries, Saia says, 62 per cent of health infrastructure lies within 500 metres of the coast. “The consequences of inaction are now too severe to ignore,” he says. “The evidence of climate‑related health harm is overwhelming and irrefutable. “As both a doctor and a former health minister, I firmly believe that health is ultimately a political choice.” What are the health impacts of sea-level rise? One of the most immediate health consequences is unsafe water, as saltwater seeps into underground freshwater sources and contaminates drinking supplies. Flooding can overwhelm sanitation systems, pushing sewage and pollutants into water sources and increasing the risk of waterborne diseases such as cholera and leptospirosis. Human migrations and displacements caused by sea-level rise also lead to overcrowding and poor conditions, fuelling the spread of infectious disease. Salinated water may lead to increases in blood pressure, with higher salt intake linked to hypertension and damage to the heart, brain, kidneys and blood vessels. And when salinated water destroys crops, populations become malnourished, with many losing their livelihoods as farmland becomes unviable. A co-chair of the commission, Prof. Kathryn Bowen, said sea-level rise would be a core component of the health chapter of the seventh report of the Intergovernmental Panel on Climate Change, the UN body that assesses the science related to climate change. “One of the core human needs is fresh water,” she says. “We’re starting to see that this salinity and contamination is linked to worse cardiovascular, renal and pregnancy related health outcomes, and we know that the combination of sea water intrusion and agricultural practices has also been linked to heavy metal sources being found in groundwater.” What are the gender inequality impacts? In some countries, women and girls are largely responsible for collecting water for cooking and sanitation, and are forced to travel further when local supplies are polluted. Longer journeys increase their exposure to sexual violence, as well as exploitation and waterborne disease. Sea-level rise also makes weather events more dangerous, as storm surges and flooding reach further inland. Crowded emergency shelters can expose women and girls to sexual violence and poor sanitation, leading some to avoid shelters altogether. Pregnant women and young children are particularly vulnerable to diseases from drinking-water contamination and disrupted healthcare access is linked to poor pregnancy outcomes and child health risks. The director general of India’s Centre for Science and Environment, Sunita Narain, said: “It is clear that women are disproportionately hit … The increased frequency and intensity of these weather events puts pressure on livelihoods and this means that the men are the first to migrate in search of work. “This then puts additional pressure on women to cope and indeed survive.” What impacts does relocation have? Even when relocation in response to the threat of sea-level rise is planned, Bowen says, deliberate and permanent relocation ahead of disaster has profound impacts, with education, housing and other critical services also needing to move. Saia has seen the health impacts of this relocation first-hand. “In the Pacific, health is inseparable from identity,” he says. “Sea‑level rise does not just take land; it erodes culture, traditions and people’s sense of belonging. “In low‑lying atoll countries such as Kiribati, Nauru, the Marshall Islands and Tuvalu, families are being pushed off ancestral land as erosion worsens and flooding becomes routine. This disrupts food systems, community practices and social cohesion.