Rice Feeds Half the World but Costs Water, Climate and Health: Scientists Demand a Planetary Health Reset

Rice is the staple crop on which more than half of humanity depends every single day, and its importance to global food security is only set to grow. Yet the flooded paddies that make rice cultivation possible carry a hidden ledger of costs that extend far beyond the grain harvest. In a comment article published in Nature Water, an international team of researchers spanning agriculture, hydrology, public health and climate science argues that these wider impacts have been managed for too long by separate sectors working in isolation, and that a planetary health approach is urgently needed to identify rice-growing practices that deliver benefits across water, climate, ecosystems and human health simultaneously.

The planetary health framework, first articulated in a landmark 2015 Lancet Commission led by Sarah Whitmee and colleagues, describes the health of human civilisation and the state of the natural systems that support it as inextricably linked. Applied to rice, the framework demands that agronomists, water engineers, climatologists, ecologists and disease specialists stop treating the paddy as a purely agricultural system and instead evaluate it as a coupled human–environment system. The authors of the new comment, drawn from institutions including the London School of Hygiene and Tropical Medicine, the World Health Organization, the International Rice Research Institute, Eawag, Deltares, the United Nations University Institute for Water, Environment and Health and several European universities, contend that this integrated lens can reveal win–win interventions that sector-by-sector analysis routinely misses.

The first and most visible cost is water. Irrigated rice is among the most water-intensive crops on the planet, traditionally grown under continuous flooding that keeps the root zone saturated throughout the growing season. Much of the water applied is lost to seepage, percolation and evaporation, placing enormous pressure on surface and groundwater resources in regions where rice dominates cropping systems. As competition for water intensifies and climate change makes supplies less reliable, water scarcity is becoming a binding constraint on rice production in major growing regions, threatening the very food security the crop is meant to guarantee.

The second cost is climatic. Continuously flooded paddies create the oxygen-depleted, or anaerobic, soil conditions in which methanogenic microorganisms thrive, making rice cultivation a substantial source of methane, a greenhouse gas far more potent than carbon dioxide over short time horizons. Reviews of the evidence, including work synthesised by Qian and colleagues in Nature Reviews Earth and Environment, have quantified the scale of these emissions and the agronomic levers that influence them. Water management sits at the heart of the problem: the same flooding that suppresses weeds and stabilises yields is what generates the methane, creating a direct tension between conventional agronomy and climate mitigation.

The third cost is the least appreciated: rice paddies can serve as habitat for the mosquitoes and snails that transmit some of the world’s most important vector-borne diseases. Standing water in irrigated agroecosystems can support Anopheles mosquitoes that transmit malaria, vectors of Japanese encephalitis and other arboviruses, and aquatic snails involved in schistosomiasis transmission. The relationship between rice systems and disease is complex and context-dependent, and a systematic review by Chan and colleagues published in Scientific Reports in 2022 examined how agricultural and environmental changes in rice-growing landscapes influence malaria risk. The historical record shows that this connection was recognised decades ago, with the International Rice Research Institute convening work on vector-borne disease control through rice agroecosystem management as early as 1988, and studies such as Mutero and colleagues in Acta Tropica in 2000 testing how water management in Kenyan irrigation schemes could reduce mosquito breeding.

Crucially, the authors argue, these three problem domains are not independent, and managing them separately can create perverse trade-offs. Alternate wetting and drying, a water-saving technique in which fields are allowed to dry intermittently rather than being kept permanently flooded, has been shown in trials reported by Lampayan and colleagues in Field Crops Research to reduce water use substantially while maintaining yields, and it also suppresses methane emissions because intermittent aeration of the soil inhibits methanogens. But the same drying cycles change the hydrology of the paddies in ways that could alter mosquito breeding habitat and snail populations, and the direction of that effect on disease transmission is not uniform across settings. Similarly, intensification strategies that raise yields may increase water demand or pesticide loads, while climate adaptation measures designed to protect rice from heat and drought may reshape the disease ecology of the landscape. Only an integrated assessment can reveal where interventions produce co-benefits and where they shift burdens from one domain to another.

The stakes of getting this wrong are rising. Expansion of rice cultivation is a central pillar of food policy across sub-Saharan Africa, where the Coalition for African Rice Development has promoted ambitious production targets as a route to import substitution and food sovereignty. Research by Jiang and colleagues has documented how rice expansion in Africa changes land and water use, while other recent work has examined the environmental consequences of intensification. If new rice schemes are designed purely for agronomic output, the comment’s authors warn, they risk locking in water stress, methane emissions and vector-borne disease burdens for decades. Conversely, if planetary health principles are embedded at the design stage, the same expansion could be steered toward practices that conserve water, limit emissions and reduce disease risk from the outset.

The technical toolkit for such integrated management already exists in pieces. Beyond alternate wetting and drying, options include site-specific water regimes tailored to local vector ecology, cultivar and fertiliser choices that influence methane fluxes, drainage and edge management that reduce breeding sites for mosquitoes and snails, and landscape-level planning that weighs rice against alternative crops in water-stressed basins. Studies such as those by Echeverría-Progulakis and colleagues in Agriculture, Ecosystems and Environment, Cuong and colleagues in Environmental Challenges, and González and colleagues in the Journal of Environmental Management have begun to quantify the environmental footprints and trade-offs of different rice management options, while work on arsenic and other contaminants in paddy systems, reviewed by Abedi and Mojiri in Plants, adds further dimensions of soil and water quality to the picture. Adaptation strategies for climate change impacts on rice physiology and agronomy, set out by Wassmann and colleagues in Advances in Agronomy, complete a portfolio that is rich in components but poor in integration.

What is missing, the authors argue, is the connective tissue: institutional arrangements, assessment methods and funding structures that allow agricultural ministries, water authorities, climate negotiators and health agencies to evaluate rice interventions on a common scoreboard. Planetary health provides precisely that common frame, treating human health outcomes, ecosystem integrity and resource sustainability as jointly optimisable objectives rather than competing claims. The comment calls for rice-growing practices to be identified and promoted on the basis of their performance across all these domains at once, which would require cross-sectoral evidence generation, from hydrological monitoring and greenhouse gas measurement to entomological surveillance and epidemiological studies, embedded within agricultural research and development programmes rather than bolted on afterwards.

The message lands at a moment when the pressures on the global rice system are unusually acute. The Food and Agriculture Organization’s Food Outlook report of November 2025 underscores the centrality of rice to world food markets, while climate volatility, water scarcity and the persistent burden of vector-borne disease in rice-growing regions all press in on the same landscapes. The authors, who note that the views expressed are their own and do not necessarily represent those of their affiliated institutions, including the World Health Organization, frame their argument not as a rejection of rice but as a defence of it: the crop’s future depends on managing its full footprint. If the planetary health approach they advocate is adopted, the world’s most important staple could be produced in ways that feed a growing population while easing, rather than deepening, the pressures on water, climate and health. The alternative, they suggest, is a system in which each sector continues to solve its own piece of the puzzle while quietly worsening everyone else’s.

Subject of Research: Integrated management of water, climate and health impacts of rice production using a planetary health framework

Article Title: A planetary health approach is needed to manage the wider impacts of rice production

Article References: Braun, L., Boisson, S., Boelee, E., Chivenge, P., Connor, M., Drakeley, C., Drew, G., Gordon, B., Irish, S. R., Lines, J., Mabhaudhi, T., Müller, M. F., Pinsach Boada, J., Arbat Pujolras, G., Said-Pullicino, D., Tharreau, D., & Cumming, O. (2026). A planetary health approach is needed to manage the wider impacts of rice production. Nature Water. https://doi.org/10.1038/s44221-026-00722-w

Image Credits: AI Generated

DOI: 10.1038/s44221-026-00722-w

Keywords: rice production, planetary health, water scarcity, methane emissions, vector-borne disease, malaria, alternate wetting and drying, food security, irrigation, climate change mitigation, schistosomiasis, sustainable agriculture