Climate change continues to increase the concentration of carbon dioxide in our atmosphere, leading to greater plant productivity during photosynthesis. As a result, one might assume that this increased growth will help meet the nutritional demands of a burgeoning world population. However, the full story is far more complex.

Plants may grow larger, but because the nutrient capacity of plants is essentially determined from the seed, a corollary increase in nutrient density is far from guaranteed. In fact, a 2004 U.S. study found that essential nutrients in some garden crops are up to 38% lower than in the middle of the last century.

Conventional agricultural methods and their contribution to reduced nutrient density

Between 1950 and the late 1960s, the Green Revolution introduced a range of new technologies to the agricultural industry, including high-yielding varieties (HYVs), which are still widely used today. These crops allowed global food supply to skyrocket, but diminished its nutritional value.

Regardless, high-yield varieties have become so prevalent that many traditional and biodiverse crops are no longer planted; since 1900, some 75% of global crop varieties have gone extinct, and many more are still being lost at a rate of one per day. Commercial agricultural models currently employ practices that are known to poison soils with chemicals, lower water quality, and decrease soil fertility. In fact, soil exhaustion due to lack of crop rotation and intense tilling has been found to reduce the nutrient density of crops.

Consequently, over the last 70 years, minerals, protein, and vitamin levels in vegetables and fruits have decreased significantly. Without a diet of diverse nutrients, humans are more susceptible to deficiencies that can cause negative health outcomes. In addition, by limiting the types of foods grown to a few species, the food supply system is more vulnerable to pests and diseases.

Weather volatility and its effects on food and nutrient availability

Over the last 50 years, the number of natural disasters has increased by a factor of five. Nevertheless, countries are under pressure to grow more crops to meet consumer demand. Some crops have been developed and chosen based on how quickly they can be grown rather than their nutritional value. Often to make up for crop loss due to climate events, intensive cropland management practices like irrigation, inorganic fertilizers, and synthetic chemicals to kill weeds and pests are becoming more common. More land is then being used for farming, causing erosion and degrading soil as more trees are cut down.

Rising global temperatures will also take a human toll. Harvesting fresh produce during heat waves and droughts will become dangerous and even lethal because fruits and vegetables are harvested mainly by hand, unlike wheat, corn, and other commercial crops, which are harvested by machines. Hurricanes, floods, and droughts are examples of extreme weather that affect small farms, which account for around 90% of the world's 570 million farms. This has repercussions for food systems and rural ways of life, including a drop in the number of farmers. The yield of these crops is likely to decline, and as a result, nutrient intake will follow. This will only exacerbate current nutrient deficiencies, as more than half of the total calories in the standard American diet are derived from highly processed foods, with only 11% of calories coming from fruits, vegetables, whole grains, beans, and nuts.

Regenerative agriculture as a solution to nutrient density loss

Adopting regenerative agricultural practices can provide a sustainable solution to combat micronutrient deficiency. This includes improving soil health, which hosts a quarter of our planet's biodiversity. Although researchers are still investigating the relationship between regenerative agriculture techniques, soil health, and nutrient density, early findings show a link between enhanced soil biodiversity and nutrient content. Ongoing research, such as that from the Rodale Institute, is exploring increased fungal and mycobacterial content in soil commonly associated with regenerative agricultural practices and its outcomes, leading to improved micronutrient content of plants.

Rising temperatures, droughts, and floods are putting global food security at risk on multiple fronts. Biodiverse farming should be adopted to lead the development of more species-rich ecosystems that are more resilient in the face of environmental changes. New innovative approaches will be necessary to ensure that people globally have consistent and equitable access to nutritional, healthy food.