Climate change, malnutrition, and poor diets are interconnected. Without well-financed climate change adaptation plans and strategies global nutrition disparities could worsen.
Malnutrition in its different forms, from undernutrition to micronutrient deficiencies to overweight and obesity, remains an important global challenge. Twenty percent of children under five years are stunted while 2.2 billion adults are overweight or obese (1). Over three billion people cannot afford a healthy diet. Malnutrition is linked to pressing global challenges like climate change which affects water resources, crop and animal species, and biodiversity loss, and contributes to food insecurity and malnutrition.
According to the World Meteorological Organization, in the past several years, the world saw record-high surface and ocean temperatures, greenhouse gas emissions, and sea levels. Arctic and Antarctic sea-ice extent were at their lowest, and glaciers in North America and the European Alps experienced extreme melt. Extreme weather events like heatwaves, cold spells, wildfires, droughts, and flooding increased in frequency, intensity, and duration. Globally, 20% of people are at risk of extreme weather events, particularly in South Asia (87%) and East Asia and the Pacific (69%). Estimates suggest that 4.5 billion people will experience extreme weather events in their lifetime.
How climate change affects human health and nutrition
Climate change has substantial effects on human physical and mental health and nutrition (2). High temperatures, temperature variability, and heatwaves contribute to the increase in heat-related mortality and poor occupational health leading to injuries, heat strain, dehydration, and more (3). Increasing temperatures and heatwaves also increase the risk of preterm birth, low birth weight, and stillbirth (3). The negative effects of climate change on mental health, both in the short- and long-term, are also well-documented (3). Acute and chronic weather events affect mood and anxiety disorders, disrupted sleep, and increase suicide risk (2).
In addition, extreme precipitation and temperatures contribute to water contamination and to the increased spread of infectious disease like dengue and malaria (3). Climate change can affect human health through decreased physical activity as well (3). While warmer temperatures increase outdoor activity, heatwaves and air pollution decrease mobility and physical activity (4). The resulting lack of exercise and physical activity reduces general health and can contribute to increased hypertension, overweight and obesity, cancer, and heart disease. These various challenges strain health systems globally (3).
Agrifood and water systems suffer from climate stress
Climate change also negatively affects human nutrition through several pathways, including its effects on agrifood systems and water systems (5,6). High temperature, erratic rainfall, droughts, and extreme weather events decrease crop yields and livestock productivity, contribute to the spread of pests and diseases, reduce fisheries, and can lead to crop failure, all of which contribute to lower food availability (5).
Higher carbon dioxide emissions, degrading soil, and pest resistance decrease the nutritional quality of crops, including staples like wheat, rice, and potatoes (5). Higher temperatures also reduce nutrient availability in seafood by changing marine areas for farming, fishmeal production, and catch size and composition.
In addition, the increased frequency and intensity of extreme weather events affect agrifood systems’ value-chains (e.g., food storage, aggregation, and distribution), reducing food availability and accessibility (7). Such disruptions contribute to rising food prices and decreased affordability of healthy diets especially among the most vulnerable and socially excluded groups (8). The resulting inadequate quantity and quality of food contributes to malnutrition (e.g., undernutrition, overweight, and obesity) and increases the risk of diet-related non-communicable disease like hypertension, diabetes, and cardiovascular disease (8).
Lastly, water systems, agrifood systems, and nutrition are closely linked. Reliable and sustainable access to clean water is a necessary component of a healthy diet and a healthy life. Improved water, sanitation, and hygiene practices decrease infections and morbidity, which is fundamental to good nutrition. Access to water is also important for food production, processing, storage and handling, and for a healthy food environment (6).
Food systems can contribute to climate change
What complicates matters further is that the relationship between climate change and agrifood systems is bidirectional (5). Food systems are sensitive to climate change just as they can contribute to climate change. As described, climate change influences agrifood systems and food consumption, which are also among the main drivers of climate change (5). Grains, fruit, and vegetables production together contribute to approximately half of environmental pressure on freshwater use, nitrogen and phosphorous application (7).
Livestock production increases greenhouse gas emissions, water contamination, and land use both directly from the animals and indirectly from animal feed production (5). In fact, livestock products (dairy and meat) are the largest contributor to agricultural greenhouse gas emissions among key food commodities (2). Unhealthy foods such as ultra-processed and packaged foods are also more greenhouse gas intensive due to their longer food supply chains, large quantities of land, water, and energy used while also contributing to biodiversity loss (9).
Poor communities mostly affected by climate change and malnutrition
The negative effects of climate change on nutrition and health are most pronounced among already vulnerable and socially excluded populations, communities, and households, especially those in low- and middle-income countries and in small island states (10). These populations are often already facing the highest burdens of malnutrition and food insecurity, and experiencing high levels of poverty. Yet, they contribute the least to greenhouse gas emissions (10).
Socio-economic and demographic dimensions relevant to specific contexts (e.g., caste, age, rural/urban divide) must be acknowledged in order to recognize, understand, and tackle the root causes of this increased vulnerability of these populations and communities and to ensure their inclusion in decision-making related to climate change and its effects on various systems (11,12).
National policies fall short of concrete actions and financial commitments
Numerous climate-smart and nutrition-sensitive adaptation strategies have been proposed to mitigate the effects of climate change on human health and nutrition through food supply chain inputs such as improved seed varieties, food production systems, biodiversity, health, water, and social protection systems (2,5).
However, linkages between climate and nutrition can be made more explicit to help decision-makers identify solutions that can simultaneously address climate and nutrition. Recent analysis from the Initiative on Climate Action and Nutrition (I-CAN) found that national climate policies such as National Adaptation Plans, Nationally Determined Contributions, and National Nutrition Plans identify climate and nutrition linkages but fall short of identifying concrete actions with financial commitment and clear institutional responsibilities. Notably, of the policies that integrated climate and nutrition or biodiversity and nutrition, more were from low- and middle-income countries than high-income countries – probably due to their different levels of climate change and malnutrition exposure.
Special focus on localised solutions is crucial
Translating these policies into strategic actions that integrate climate and nutrition is important. However, existing recommendations suffer from drawbacks. First, most recommendations are general, proposing global solutions that treat all countries the same regardless of differences in exposure to climate change and severity of consequences. Although studies focusing on low- and middle-income countries or specific regions like Africa find results consistent with high-income countries and across super-regions, substantial disparities remain within countries and within smaller geographical regions. Recent findings indicate the need for localised solutions to climate change adaptation and mitigation (13).
Second, and related, translating policies and plans into solutions for climate change adaptation and mitigations should consider and involve local stakeholders through collaborative efforts in data, capacity, co-creation of projects and interventions, and multistakeholder processes. Such approaches strengthen linkages between research, policy, and society (14).
Ensuring the representation of diverse actors and groups, including women, youth, and indigenous communities strengthens the identification of potential solutions by incorporating traditional and local knowledge systems (11,14). For example, indigenous communities have contributed to biodiversity conservation by sharing their sustainable and nutritious food practices that enhance resilience against environmental challenges. Many natural-resource management practices that are promoted for climate-change adaptation and mitigation, including biodiversity conservation and governance systems that protect ecosystems, are also grounded in traditional knowledge of Indigenous Peoples.
Multisectoral participatory forums or collaborative networks that bring together diverse actors and their specific skillset can strengthen actions. For instance, government organisations prioritise policy but can sometimes lack the research and capacity-building efforts necessary for actionable programmes. Meanwhile, civil society organisations mainly focus on policy advocacy and service delivery in communities rather than studying and identifying evidence-based solutions. Partnerships with researchers and institutions in low- and middle-income will also be important and this can be facilitated through funding mechanisms that support such partnerships.
Global nutrition disparities will widen - robust policies and plans are vital
Climate change, malnutrition, and poor diets are interconnected. As climate change intensifies, its effects on agrifood systems, water resources, health, and nutrition will continue to exacerbate. Global nutrition disparities will continue to widen, particularly among nutritionally vulnerable populations (e.g., pregnant women, young children, and adolescents), socially excluded groups, and those living in areas susceptible to climate change threats. While policies and plans increasingly recognise the link between climate and nutrition, many lack concrete, context-specific actions with financial and institutional backing.
Stronger coordination, integrated actions, and localised and inclusive approaches are simultaneously needed to effectively tackle these challenges. Integrating traditional and local knowledge, fostering multisectoral collaboration, and ensuring the active participation of diverse stakeholders – especially those most affected and near the ramifications of these challenges – can help prioritise research gaps; design, implement, and test potential solutions; and enhance the resilience and sustainability of solutions. Strengthening research-policy linkages and prioritising equity will help develop adaptive strategies that safeguard both human and planetary health for this and future generations.
All views expressed in the Welternährung are those of the authors and do not necessarily reflect the view or policies of the editorial board or of Welthungerhilfe.
Lilia Bliznashka: International Food Policy Research Institute (IFPRI)
Elyse Iruhiriye: International Food Policy Research Institute (IFPRI)