The article, authored by a team from Harvard School of Public Health and other institutions, highlights the significant impact of rising atmospheric CO₂ levels on the nutritional content of C3 grains and legumes. The study, which includes meta-analyses of data from 143 comparisons across seven FACE (Free-Air CO₂ Enrichment) experimental sites in Japan, Australia, and the United States, found that elevated CO₂ concentrations significantly decrease the zinc, iron, and protein content in these crops. Specifically, wheat grains grown at elevated CO₂ levels had 9.3% lower zinc and 5.1% lower iron content compared to those grown under ambient CO₂ conditions. The study also noted that C4 crops were less affected, with only maize showing a decrease in iron content. The authors suggest that breeding programs could potentially address these issues by developing crop varieties that are less sensitive to elevated CO₂ levels, thereby reducing the risk of dietary deficiencies in populations that rely heavily on C3 grains and legumes for zinc and iron. The findings emphasize the urgent need for adaptive strategies to mitigate the adverse effects of climate change on global food security and public health.The article, authored by a team from Harvard School of Public Health and other institutions, highlights the significant impact of rising atmospheric CO₂ levels on the nutritional content of C3 grains and legumes. The study, which includes meta-analyses of data from 143 comparisons across seven FACE (Free-Air CO₂ Enrichment) experimental sites in Japan, Australia, and the United States, found that elevated CO₂ concentrations significantly decrease the zinc, iron, and protein content in these crops. Specifically, wheat grains grown at elevated CO₂ levels had 9.3% lower zinc and 5.1% lower iron content compared to those grown under ambient CO₂ conditions. The study also noted that C4 crops were less affected, with only maize showing a decrease in iron content. The authors suggest that breeding programs could potentially address these issues by developing crop varieties that are less sensitive to elevated CO₂ levels, thereby reducing the risk of dietary deficiencies in populations that rely heavily on C3 grains and legumes for zinc and iron. The findings emphasize the urgent need for adaptive strategies to mitigate the adverse effects of climate change on global food security and public health.