When it comes to food and climate change, the discussion usually centers around climate change causing harvests to decrease in quantity. However, what may not be as widely discussed as the impact of climate change on the nutrition of the food we consume. 

Recent research suggests that higher levels of carbon dioxide (CO2) in the atmosphere can result in decreasing nutritional quality of some important staple crops. Even if the number of calories stays the same, people may be getting fewer of the nutrients that are important in order to stay healthy. 

Why This Matters

• Rising CO₂ is making our staple foods less nutritious. Even if we have enough calories to eat, we may not be getting the vitamins and minerals our bodies need to stay healthy, affecting billions of people who depend on crops like rice.
• The burden falls heaviest on the world’s poorest populations. Those least able to afford alternative nutrient sources will be most vulnerable to deficiencies, while wealthier households can adapt by diversifying their diets.
• The economic costs of inaction far exceed the cost of prevention. Healthcare expenses, lost productivity, reduced educational outcomes, and shortened lifespans could cost billions annually, making nutritional adaptations now a far cheaper investment than managing these consequences later.

Nutrition in Rice 

A 2019 study by Matthew Smith and Samuel Myers looked at the intersection between climate change and nutrients in rice, one of the world’s most important staple foods. The findings from the study suggest that rising CO2 could reduce several B vitamins in rice and increase the risk of nutritional deficiencies. 

However, the effects could extend well beyond nutrition. Less nutritious diets can lead to more illnesses, higher healthcare costs, lower productivity, and greater pressure on household budgets. 

According to the study, rice provides approximately 19% of global calories, and more than half of the world’s population gets more than one-quarter of its daily calories from rice. In the study, researchers looked at experiments in which rice was grown under higher CO2 concentrations. The results showed reductions of approximately 17% to 30% in thiamin, riboflavin, and folate, three important B vitamins.  

Researchers then modeled the potential impact on nutrition around the world. By around 2050, they estimated that these changes could put an additional 132 million people at risk of folate deficiency, 67 million at risk of thiamin deficiency, and 40 million at risk of riboflavin deficiency. 

These numbers do not automatically imply that all of these people would become sick though. Instead, these estimates indicate that more people could fall below recommended levels of nutrient intake. 

Unfortunately, rice is only one piece of the puzzle. In the same study, researchers discovered that higher amounts of CO2 can reduce key nutrients such as protein, iron, and zinc in many other staple crops such as wheat, maize, and potatoes. While rice receives a lot of focus in this study, the broader impact of climate change on nutrition could therefore be much larger when all crops and food sources are taken into consideration. 

Impact on Healthcare 

As a result of decreased nutrition, health becomes a big consequence both physically and economically. 

The National Institutes of Health (NIH) explain that folate is especially important during pregnancy because adequate intake helps prevent neural tube defects (NTDs). Smith and Myers estimate that the reduction in folate from rice could contribute to approximately 260 additional deaths and 27,900 additional life-years lost each year as a direct result of NTDs. While these may not seem like drastic numbers, the research shows that both the increase in deaths and life years lost results in an increase of 0.5% over current rates. 

This is only one possible health effect. The study does not attempt to quantify all of the health consequences of folate, thiamin, or riboflavin deficiencies, nor does it account for changes in other crops. 

Moreover, health problems involving nutrition can also be an economic burden. Costs can include hospital bills, long term treatment, rehabilitation, special education, caregiving, and lost income. 

A separate study on folic acid fortification (adding synthetic vitamins to staple foods) highlights just how large these costs can become. A study published in 2005 estimated that folic acid fortification generated $312 million to $425 million in annual economic benefits, including savings from preventing neural tube defects.  

While these figures cannot be directly applied to the climate-related effects in the rice study, they do show that preventing nutrition-related disease can lead to economic benefits far greater than the cost of the intervention. 

On a broader level, climate change is already causing many health problems. The World Health Organization (WHO) estimates that climate change could cause approximately 250,000 additional deaths each year between 2030 and 2050 from malnutrition, malaria, diseases, and heat stress. WHO also estimates that direct health costs from climate change could reach $2 billion to $4 billion per year by 2030. 

Beyond Healthcare 

The economic effects of poor nutrition go beyond healthcare. Nutrition affects physical health, cognitive development, school attendance, and the ability to work. Poor nutrition can therefore lead to more sick days, lower productivity, and reduced earnings. 

The effects can also last for decades. When nutritional deficiencies affect children, they can influence development and educational outcomes, potentially affecting their future ability to earn an income. 

Another economic consideration is the cost of getting enough nutrients. If prices stay the same, but there are less nutrients, then you would likely need to buy more to get the same amount of nutrients you were getting before. If we look specifically at rice, lower nutrients in rice could result in a need to buy more vegetables, eggs, meat, fortified foods, or other supplements in order to get the nutrients previously provided by rice. 

Furthermore, the cost of eating a healthy diet has increased, even if the price of rice hasn’t gone up by much. This is especially concerning because healthy diets are already out of reach for many people around the world. According to the World Bank Group, the global average cost of a healthy diet reached $4.28 per person per day in 2025, while approximately 2.7 billion people could not afford a healthy diet. That is nearly 33% of our total world population. 

For wealthier households, it may be relatively easier to adjust to changes in the nutrients level of rice or other staples by eating a more diverse diet. However, for lower-income households that depend heavily on less expensive staples, there may be fewer affordable alternatives. This results in a big inequality as individuals most vulnerable to climate-related nutritional losses may also be the least able to afford nutrient-equivalent alternatives. 

Preventing Larger Costs 

While the figures in the study may not appear to be the most positive, there are potential ways to combat and adapt to this situation. For instance, research suggests that we could develop different crops that retain more nutrients under higher CO2 levels, diversify our diets, and expand food fortification. 

Folic-acid fortification serves as a prime example of a potential adaptation. Research has shown that relatively inexpensive fortification programs can prevent serious health problems and generate substantial economic benefits. Ultimately, investing in nutritional adaptations now could be far less expensive than dealing with the health and economic consequences later. 

Adapting to New Challenges 

The research on rice and CO2 also highlights an important gap in how we think about nutrition and having enough to eat. It is important to not just eat enough calories, but to also get enough nutrients to stay healthy. 

Intense heat, drought, and extreme weather can decrease the amount of food available, while rising CO2 can reduce its nutrients. While some people may have enough food to eat, they might not be getting enough nutrition. 

Thus, the solution is not to just grow more food but instead ensure that the food we grow continues to provide enough nutrition, at a price people can afford, in a changing climate. 

Cover image: DesignStrive Studio on Unsplash.