Rising CO₂ Is Making Food Less Nutritious, Study Finds

Rising levels of atmospheric carbon dioxide are altering the nutritional makeup of food, according to new research that adds a subtle but far-reaching dimension to the climate challenge. The study finds that higher CO₂ concentrations stimulate plant growth in ways that increase carbohydrate content—making foods more calorific—while simultaneously reducing levels of essential nutrients such as protein, iron, zinc, and certain vitamins.

Researchers examined staple crops including wheat, rice, and legumes, which form the dietary foundation for billions of people worldwide. While plants exposed to elevated CO₂ often grow faster and larger, the dilution effect reduces their nutritional density. In practical terms, this means people may need to consume more food to obtain the same nutritional value, a shift that carries implications for global health, especially in regions already vulnerable to malnutrition.

The findings suggest that climate change is not only a question of yields and extreme weather, but also of food quality. As carbon dioxide levels continue to rise, the nutritional degradation of crops could place additional strain on healthcare systems, exacerbate inequality, and complicate efforts to ensure long-term food security.

The study underscores the need for a broader view of climate risk—one that accounts not just for environmental and economic impacts, but also for the less visible changes affecting human health and resilience over time.