“On average, these nutrients decrease by 4.4%, but there are also decreases of 38%,” write the researchers. In addition, the number of calories increases, which can lead to more obesity. In addition, there are indications that the amount of harmful substances such as lead in crops is increasing, but this requires further research.
Research since the 1970s
Since the 1970s it has been thought that when we add CO2 to crops, they grow faster and we have more food. A great solution against climate change, it was thought. At the same time, research has also been conducted since then into what the effect of adding CO2 is on the quality of the food. Ter Haar compared these studies. That was not easy: a different concentration of CO2 was added each time in the studies. In addition, the amount of CO2 in the air has increased over the years.
Ultimately we managed to compare the data. This shows that if the CO2 content doubles, the influence on the nutrients in crops also doubles. The study looked at 43 types of crops, including wheat, tomatoes, potatoes and rice.
Wake-up call
Ter Haar sees her study as a wake-up call. “We often think of food security as whether people can fill their stomachs. With our research we emphasize that food security also means that our food contains sufficient nutrients. We must pay more attention to this.”
date:2026-02-08 10:03:00