Higher carbon dioxide makes food more calorific – but less nutritious, study finds
Climate change affects not only how much food we grow, but also what that food contains.
A recent report in The Guardian highlights research showing that higher atmospheric carbon dioxide levels can increase the caloric content of staple crops while reducing their nutritional value. The result is food that fills stomachs but provides fewer essential nutrients.
External source (opens in a new tab): Higher carbon dioxide makes food more calorific – but less nutritious, study finds
What the research indicates
- Elevated CO₂ tends to increase carbohydrates (sugars and starches) in crops such as wheat and rice.
- At the same time, concentrations of key nutrients — including protein, iron, and zinc — often decline.
- This combination raises the risk of “hidden hunger”, where people consume enough calories but lack essential micronutrients.
Why this matters for food security
Reduced nutritional quality compounds other climate-driven stresses on food systems, including heat, drought, and rising pest pressures. Even where crop yields are maintained, declining nutrient density can worsen health outcomes, especially for children and vulnerable populations.
GOF perspective
This research reinforces the need to think beyond yield alone. Climate action must address food quality as well as quantity — supporting resilient farming systems, crop diversity, and local adaptation strategies that protect nutrition as the climate changes.
Source: The Guardian (external link). This page provides original commentary by The Green Offsets Foundation of Canada.
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