Michelle Tigchelaar

Blue food -aquatic organisms fished or farmed in marine and freshwater areas, including fish, shellfish, and aquatic plants -make critical contributions to nutrition, livelihoods, and economies, and can have lower carbon footprints than other animal-source foods. While blue foods are increasingly discussed as part of climate change mitigation and adaptation, climate change also affects the feasibility, performance, and equity outcomes of blue food strategies, and evaluations of such strategies remain limited. Through an expert-driven, iterative process, we review 22 strategies through which blue foods may contribute to climate mitigation or adaptation, consolidating evidence on their potential effectiveness, feasibility, and associated trade-offs and synergies across sustainable development outcomes. The reviewed literature provides relatively good evidence for the mitigation potential of Decarbonizing production practices and Dietary shifts, and for adaptation benefits associated with Species and gear shifts. However, evidence across strategies remains uneven, highly context-specific, and in some cases limited. Trade-offs with sustainable development outcomes, risks of maladaptation, and a persistent bias in research and policy towards technological innovation over systemic and societal change complicate evaluation and implementation of blue food climate strategies. No single strategy emerges as transformative in isolation. Rather, findings suggest that contextappropriate portfolios of strategies, implemented in combination, may offer complementary and synergistic benefits. Further research and evaluation are needed to substantiate claims about the transformative potential of blue foods, including systems-based analyses and targeted assessments of individual strategies, with particular attention paid to capacity-strengthening measures and equity in design and implementation.

Global nutrition targets remain unmet, as over half of preschool-aged children and two-thirds of non-pregnant women of reproductive age worldwide suffer from micronutrient deficiencies. Climate change poses a growing threat to global food and nutrition security, but existing climate risk assessments often overlook the critical roles of both terrestrial and aquatic nutrient-rich foods that are vital for dietary diversity and micronutrient supply. In this study, we introduce an innovative framework that integrates data on future climate extremes, nutrient supply dependencies, and diet-related climate vulnerability. Our comprehensive analysis assesses nutrition-sensitive climate risk to five essential micronutrients across production systems. By mid-century (2041–2060), we estimate that 75% of calcium, 30% of folate, 39% of iron, 68% of vitamin A, and 79% of vitamin B12 produced in primary food products will face frequent climate extremes (at least every other year) globally. Nearly fifty countries are projected to face high domestic climate risk for two or more micronutrients during this period, with ten countries facing high risk across all five. We outline distinct climate risk profiles to offer data-driven entry points into strategies for bolstering the resilience of micronutrient supply chains and advancing progress toward global nutrient targets in the face of a changing climate.

Global aquatic or ‘blue’ foods, essential to over 3.2 billion people, face challenges of maintaining supply in a changing environment while adhering to safety and sustainability standards. Despite the growing concerns over their environmental impacts, limited attention has been paid to how blue food production is influenced by anthropogenic environmental changes. Here we assess the vulnerability of global blue food systems to predominant environmental disturbances and predict the spatial impacts. Over 90% of global blue food production faces substantial risks from environmental change, with the major producers in Asia and the United States facing the greatest threats. Capture fisheries generally demonstrate higher vulnerability than aquaculture in marine environments, while the opposite is true in freshwater environments. While threats to production quantity are widespread across marine and inland systems, food safety risks are concentrated within a few countries. Identifying and supporting mitigation and adaptation measures in response to environmental stressors is particularly important in developing countries in Asia, Latin America and Africa where risks are high and national response capacities are low. These findings lay groundwork for future work to map environmental threats and opportunities, aiding strategic planning and policy development for resilient and sustainable blue food production under changing conditions.

Blue foods, sourced in aquatic environments, are important for the economies, livelihoods, nutritional security and cultures of people in many nations. They are often nutrient rich¹, generate lower emissions and impacts on land and water than many terrestrial meats², and contribute to the health³, wellbeing and livelihoods of many rural communities⁴. The Blue Food Assessment recently evaluated nutritional, environmental, economic and justice dimensions of blue foods globally. Here we integrate these findings and translate them into four policy objectives to help realize the contributions that blue foods can make to national food systems around the world: ensuring supplies of critical nutrients, providing healthy alternatives to terrestrial meat, reducing dietary environmental footprints and safeguarding blue food contributions to nutrition, just economies and livelihoods under a changing climate. To account for how context-specific environmental, socio-economic and cultural aspects affect this contribution, we assess the relevance of each policy objective for individual countries, and examine associated co-benefits and trade-offs at national and international scales. We find that in many African and South American nations, facilitating consumption of culturally relevant blue food, especially among nutritionally vulnerable population segments, could address vitamin B₁₂and omega-3 deficiencies. Meanwhile, in many global North nations, cardiovascular disease rates and large greenhouse gas footprints from ruminant meat intake could be lowered through moderate consumption of seafood with low environmental impact. The analytical framework we provide also identifies countries with high future risk, for whom climate adaptation of blue food systems will be particularly important. Overall the framework helps decision makers to assess the blue food policy objectives most relevant to their geographies, and to compare and contrast the benefits and trade-offs associated with pursuing these objectives.

Working in hot and potentially humid conditions creates health and well-being risks that will increase as the planet warms. It has been proposed that workers could adapt to increasing temperatures by moving labor from midday to cooler hours. Here, we use reanalysis data to show that in the current climate approximately 30% of global heavy labor losses in the workday could be recovered by moving labor from the hottest hours of the day. However, we show that this particular workshift adaptation potential is lost at a rate of about 2% per degree of global warming as early morning heat exposure rises to unsafe levels for continuous work, with worker productivity losses accelerating under higher warming levels. These findings emphasize the importance of finding alternative adaptation mechanisms to keep workers safe, as well as the importance of limiting global warming.

Aquatic foods from marine and freshwater systems are critical to the nutrition, health, livelihoods, economies and cultures of billions of people worldwide, but climate-related hazards may compromise their ability to provide these benefits. Here, we estimate national-level aquatic food system climate risk using an integrative food systems approach that connects climate hazards impacting marine and freshwater capture fisheries and aquaculture to their contributions to sustainable food system outcomes. We show that without mitigation, climate hazards pose high risks to nutritional, social, economic and environmental outcomes worldwide—especially for wild-capture fisheries in Africa, South and Southeast Asia, and Small Island Developing States. For countries projected to experience compound climate risks, reducing societal vulnerabilities can lower climate risk by margins similar to meeting Paris Agreement mitigation targets. System-level interventions addressing dimensions such as governance, gender equity and poverty are needed to enhance aquatic and terrestrial food system resilience and provide investments with large co-benefits towards meeting the Sustainable Development Goals.