Nutritional Cost of Climate Change: Declines in Protein, Fiber, Seafood Omega-3s, and Micronutrients Threaten Children and Rural Communities

Climate change is widely recognized as a significant threat to global food systems, yet its precise impact on human nutritional intake remains insufficiently quantified. Previous research has primarily examined agricultural productivity and disruptions to food supply, overlooking the subsequent implications for nutrient intake. We present the first global empirical analysis of how rising temperatures affect actual human nutrient intake across 185 countries, using data from 1990 to 2018. By integrating high-resolution climate data with nationally representative dietary intake estimates, we find that global warming undermines human nutrition: each 1 °C increase in mean global temperature reduces per-capita daily intakes of vitamin A and dietary fiber by over 1 %, while the decline in seafood-derived ω-3 fats reaches 2.12 %. These impacts are disproportionately borne by children, rural populations, and low-income countries, and have intensified over time. Projections under high-emission SSP5–8.5 scenario suggest further widespread nutritional deterioration by the year 2100, with omega-3 fat and vitamin A intake declining by over 20% in many regions. Our findings reveal an overlooked aspect of climate vulnerability: the decline in dietary quality, underscoring the need to integrate high-resolution, nutrition-sensitive strategies into climate adaptation and food policy.