Climate change threatens global food security by disrupting the four pillars of food systems identified by the Food and Agriculture Organization of the United Nations. Francesco N. Tubiello at the Food and Agriculture Organization highlights how production, access, utilization, and stability are all sensitive to changing temperature, precipitation, and extreme events. Scientific evidence from crop scientists and climate researchers shows that these changes will be uneven, producing winners and losers across regions and cultures.
Impacts on crop yields and livestock
Rising average temperatures and more frequent heat extremes reduce yields for staples such as wheat, rice, and maize in many low- and middle-income regions. David Lobell at Stanford University has documented that heat stress during critical growth stages already depresses yields and will do so more often as warming continues. In some high-latitude areas, longer growing seasons may temporarily raise production, but those gains are limited by soil, pests, and infrastructure. Samuel Myers at Harvard T.H. Chan School of Public Health has demonstrated that elevated carbon dioxide concentrations can increase yields for certain crops but simultaneously lower protein and micronutrient concentrations, with implications for nutritional quality. Livestock face heat stress, reduced forage quality, and shifting disease burdens, affecting pastoral and mixed farming systems deeply rooted in local cultures across Africa and Asia.
Water, soil, and fisheries
Water availability and timing are crucial. Cynthia Rosenzweig at NASA Goddard Institute for Space Studies and Columbia University has emphasized that altered rainfall patterns and glacier retreat will change irrigation needs and river flows, threatening communities dependent on predictable monsoon and meltwater regimes. Soil degradation, erosion from intense rainfall, and coastal salinization from sea-level rise further erode productive land, disproportionately affecting smallholder farmers and Indigenous territories where land tenure is insecure. Fisheries and aquaculture are shifting as ocean warming redistributes species; Daniel Pauly at the University of British Columbia documents poleward movements and changing catch composition, with small island states and coastal communities facing profound cultural and economic losses.
Consequences and responses
The human consequences include higher food prices, increased volatility of supply, and greater risk of undernutrition and micronutrient deficiencies, particularly among vulnerable populations in Sub-Saharan Africa, South Asia, and low-lying island nations. Food system shocks can trigger migration and amplify local conflicts when governance and safety nets are weak. Adaptation measures—breeding heat- and drought-tolerant crop varieties, improving irrigation efficiency, restoring soils, protecting fisheries habitats, and strengthening social protection—can reduce risks but require coordinated finance and policy. Sonja Vermeulen at the CGIAR research network underscores that combining mitigation with adaptation in agriculture, guided by local knowledge and equitable governance, is essential to preserve livelihoods and cultural foodways.
Addressing the challenge demands integrated action: targeted investments in resilient agriculture, inclusive governance for resource access, and global efforts to limit warming. The scientific evidence from researchers and institutions across climate, agricultural, and public health fields converges on a clear conclusion: without rapid emission reductions and substantial adaptation support, climate change will substantially undermine global food security and deepen existing inequalities.