Monthly national water and carbon accounting of desalination-linked balance closure in the Maldives

Abstract Water-scarce island nations increasingly rely on seawater desalination, but national accounting of water supply, demand and associated carbon emissions is often limited. Here we develop a reproducible monthly accounting framework for the Maldives that integrates corrected rainfall estimates, evaporation, tourism-adjusted water demand, desalination production and electricity-related carbon emissions into a single national ledger. The framework combines reported desalination output with production inferred from installed capacity and operating levels. The ledger does not represent variation among islands, storage behaviour or behavioural responses in water use. Across 2005–2010, 2018–2020 and 2021–2024, the mean monthly imbalance shifts from a surplus of about 0.93 million cubic metres to deficits of about 0.43 and 0.09 million cubic metres as desalination expands. Even under optimistic rainwater harvesting assumptions, desalination supplies most water. Associated carbon emissions highlight the importance of cleaner electricity, improved efficiency and complementary rainwater harvesting and storage options.