Rising carbon dioxide makes crops grow bigger but less nutritious

Increasing levels of atmospheric carbon dioxide are raising concerns about extreme weather and rising temperatures. They are also prompting scientists to examine how crops are responding to these changes, particularly in terms of yield and nutritional quality.

Global research on C3 plants, which include wheat, rice, and many vegetables, suggests that extra carbon dioxide can raise photosynthesis rates in certain species.

That might sound like good news, but the same studies flag worrisome drops in proteins, vitamins, and minerals – sparking concerns about protein-calorie malnutrition and micronutrient deficiency in regions that already struggle with poor soil.

Felix D. Dakora from Tshwane University of Technology and fellow researchers have studied these trends to find ways to guard future harvests against the pitfalls of high carbon dioxide exposure.

The team examined both the reasons behind these nutrient drops and what can be done to lessen the damage. The study also highlights the ripple effects that might harm food security for billions of people across the planet.

The dual impact of CO2

Elevated carbon dioxide often boosts plant growth in C3 plants by improving water-use efficiency through lower stomatal conductance and transpiration.

That can be a plus in regions where drought looms. Yet at the same time, certain crops end up with reduced nitrogen content, which dents the protein makeup. The research team reported a 7.4% decrease in wheat grain protein under high carbon dioxide.

Lower protein weakens the nutritional value of these grains. It may also bring about a rise in starchy components, which could lead to higher rates of diabetes in areas that already rely on carbohydrate-heavy diets.

Some experts believe the shift in amino acids, vitamins, and mineral levels might be an even bigger worry down the road.

Carbon dioxide lowers crop nutrition

Scientists find that soil minerals, like zinc and iron, drop in grains raised in carbon-dioxide-rich fields.

In maize, certain studies show lower levels of iron and copper that can hinder basic human dietary needs. This is particularly alarming in places where these nutrients are already scarce.

Experts note that reduced biofortification traits in many crop varieties contribute to the problem. Slowed mineral uptake and altered enzyme activities also play a part. Under high carbon dioxide conditions, some plants downregulate processes that normally absorb and distribute minerals.

Strategies for a healthier harvest

Researchers recommend selecting crop genotypes that hold onto vital elements even when gas levels climb. Some varieties appear to lose fewer nutrients, and programs aimed at improving mineral uptake could protect farmers from yield losses.

Shifting to more legume-based meals is another option. Beans and peas rely on N2 fixation, which generally holds better under high carbon dioxide compared to mineral nitrogen sources in fertilizers.

Tree planting can lock extra carbon into forests and farmland. Trees enhance soil structure and create a friendlier habitat for microbes involved in natural fertilization.

Some efforts, including large-scale planting of N2-fixing shrubs, may cut back on fertilizer use and slow the buildup of greenhouse gases.

Crops that can withstand carbon dioxide

Scientists are turning to artificial intelligence (AI) and high-tech breeding to pinpoint genetic traits that help crops cope with carbon dioxide surges.

Tools that assess growth, water usage, and nutrient density help experts spot patterns hidden to the naked eye. By mixing big data with genomics, plant breeders can zero in on seeds that are more resilient, saving both time and resources.

AI also allows researchers to simulate future conditions more accurately. This leads to better predictions for how certain crop lines will adapt.

Optimizing for stronger nutrient uptake may keep harvests robust and nutritious, ensuring fewer communities suffer malnutrition.

Diverse crops reduce the impacts

Planting diverse species that can thrive under changing conditions helps build a buffer for unpredictable swings in climate.

Combining species with strong carbon uptake could also reduce the negative side effects of high carbon dioxide. Drawing on local biodiversity and building varied cropping systems often stabilizes production and dietary quality.

Communities near desert regions, where farmland is fragile, might see benefits from more shrubs and trees suited to local conditions. These species could capture extra carbon while strengthening the soil for staple crops.

Experts say small-scale experiments are already successful in certain parts of Africa, building new paths toward long-term food security.

Protecting tomorrow’s food supply

Many scientists emphasize the need to explore how carbon dioxide interacts with other factors like temperature and extreme weather events.

Finding ways to keep proteins, amino acids, and essential minerals from eroding will be key to meeting global nutrition standards.

Switching to diets richer in legumes and vegetables may trim greenhouse gas emissions from livestock. This can also bring more variety to local plates, adding proteins and minerals that cereals under carbon stress might lack.

Meanwhile, regional approaches to reforestation and soil restoration can draw down some portion of atmospheric carbon.

Policy shifts will matter, too. If governments support research into better seed varieties and push for climate-smart irrigation methods, farmers will be more prepared. Collaboration between scientists, local communities, and industry groups could speed up large-scale solutions.

People who depend on common grains may have the most to lose from inaction. By staying alert to nutrient drops now, it may be possible to avoid bigger crises later.

The study is published in Engineering.

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