Climate change cuts crop nutrition, threatening global food security

September 3, 2026 at 09:00 PM2 min

This digest was compiled by AI from multiple sources — links to the originals are below.

Rising atmospheric carbon dioxide is reducing protein, zinc, and iron in staple crops, with global CO2 levels now above 420 ppm. By 2050, an additional 175 million people could face zinc deficiency and 122 million protein deficiency, a 2018 study found. Colorado's 2026 winter wheat harvest was the smallest since 1965, with 73% of crops in poor or very poor condition.

Key Facts

Colorado's 2026 winter wheat harvest was the smallest since 1965, with 73% of crops rated poor or very poor.
Global monthly average CO2 concentration now exceeds 420 ppm, compared with a preindustrial average of 280 ppm.
By 2050, elevated CO2 could add 175 million people to zinc deficiency and 122 million to protein deficiency, a 2018 study found.
Crops grown under higher CO2 levels show reduced zinc, protein, magnesium, and iron content.
Andrew Hultgren, an environmental economist at the University of Illinois, Urbana-Champaign, warns of real food security and nutrition concerns under high-warming futures.

Crop Nutrition Decline

Crops grown under elevated carbon dioxide levels are deficient in zinc, protein, magnesium, iron, and other micronutrients. The global monthly average CO2 concentration is now over 420 ppm, well above the preindustrial average of 280 ppm. By the end of the century, CO2 levels will reach at least 550 ppm in all but the most optimistic scenarios. A 2018 study projected that by 2050, an additional 175 million people will be zinc deficient and 122 million protein deficient due to CO2 effects alone. Zinc deficiency impairs immune and skin health and may cause poor childhood growth; protein deficiency can lead to stunted growth, fatigue, muscle weakness, and stress fractures.

Colorado Wheat Failure

Colorado's winter wheat crop faced a warm, dry winter followed by a 12-hour freeze and temperatures near 90°F two days later. Final harvest numbers in July showed 73% of crops in poor or very poor condition. Early estimates by Colorado Wheat indicate the 2026 winter wheat crop was the smallest in the state since 1965. Extreme weather and climate change are disrupting food supplies across crops, with impacts felt most intensely in less-developed regions.

Global Food Security

The U.S. faces significant changes to its food systems, and no one is immune to the effects. Andrew Hultgren, an environmental economist at the University of Illinois, Urbana-Champaign, said there are real food security and nutrition concerns, especially under high-warming futures. Crops are already less nutritious than in the 1950s, partly due to breeding decisions that prioritize yield over nutrition. The CO2-driven nutrient decline will exacerbate this existing nutrition decline.