Researchers Question Claims on GMO Crop Yields, Climate Resilience

Indiana farmers ride a tractor through their cornfield, in a file photo. Scott Olson/Getty Images

Proponents of genetic engineering in agriculture have long argued that genetically modified organisms (GMO) produce better crop yields than their natural counterparts. In recent years, GMOs have also been touted as being better for the climate and resistant to erratic weather.

But some researchers dispute these claims, and public polling shows that consumers have mixed feelings about GMOs.

Introduced into U.S. commercial agriculture in 1996, GMOs have been a point of controversy among farmers and environmental groups such as Greenpeace, while U.S. consumers have grown increasingly distrustful of the health consequences of eating genetically modified foods.

In a 2019 Pew Research Center survey, 51 percent of respondents said they thought GMOs were worse for human health than non-GMOs, an increase from 39 percent in 2016. But 74 percent also said they believed GMOs were either “fairly likely” or “very likely” to increase the global food supply, and 62 percent said the same about GMOs allowing for more affordable food prices.

At the same time, organic foods—non-GMOs produced without the use of certain substances or processes—have a growing consumer base, according to survey data from Civic Science.

A representative at the Non-GMO Project told The Epoch Times that the organization has seen a growing demand for products with its verified label.

“The Non-GMO Project is the most widely recognized food certification after USDA organic. Products with our label represent over 120,000 SKUs with over $45 billion in total sales across 99 grocery store categories,” the spokesperson said, noting that this number does not include produce sold by the pound or bulk food items.

The organization said grocery store shoppers specifically look for its trademark label when making purchasing decisions.

“The Non-GMO Project standard is a rigorous addition to the National Organic Program that provides testing, surveillance, and protection from GMO contamination,” the spokesperson said.

Sales data support the claim that more consumers are looking for organic and non-GMO products. The Organic Trade Association reported record U.S. sales of organic products in 2023, totaling nearly $70 billion.

Measuring Yields

When it comes to measuring crop production, there are two types of yields: intrinsic and operational.

Intrinsic yield is the highest possible bar for calculation because it’s obtained when crops are grown under ideal conditions, whereas operational yields are determined by actual field conditions.

The Union of Concerned Scientists, a nonprofit organization, published a study in 2009 examining 13 years of GMO use in U.S. commercial agriculture. The study found that genetically modified corn and soy didn’t produce any intrinsic yield gains.

Additionally, there was only a minimal operational yield gain observed over the same period.

Researchers examined data related to corn and soybean production since the early 1990s—before GMOs entered farming—and found that although yields increased overall, this was largely attributed to traditional breeding methods and improved agricultural practices.

More than 90 percent of the corn, soybeans, and upland cotton in the United States is grown using genetically engineered varieties, according to the U.S. Department of Agriculture (USDA), meaning that they are a reliable measuring tool in understanding the success or failure of GMOs in large-scale crop production.

In a March report, the USDA predicted that corn yields will increase by only 3.1 percent by 2036, which the agency described as a “historically slow” rate, and that soybean yields will decrease by 3 percent in the same period, resulting in a predicted $256 million loss in exports.

Kaiser Jamil is the president of the Third World Organization for Women in Science, which is part of the U.N. Educational, Scientific, and Cultural Organization.

In an article for the UN Chronicle, Jamil stated that there are valid concerns about the potential pitfalls of using genetic engineering in farming.

“Genetically modified crops can potentially fail to germinate; kill organisms other than pests that are beneficial to plants and reduce soil fertility; and potentially transfer insecticidal properties or virus resistance to wild relatives of the crop species,” she wrote.

But Jamil also outlined potential benefits, such as alleviating hunger and malnutrition in developing countries.

She highlighted golden rice, a type of rice that’s genetically modified to address vitamin A deficiency, which causes blindness in as many as 500,000 children from impoverished areas each year, she said. The rice is modified to contain beta carotene—which the human body converts to vitamin A—by introducing two genes from the daffodil plant and one from a bacterium.

“This is just one among the hundreds of new biotech products, which point to the contributions of biotechnology to society,” Jamil said.

Climate Claims Challenged

In a 2021 paper published in the journal Sustainability, researchers claimed that using herbicide-tolerant crops along with glyphosate to control weeds allowed farmers to minimize tillage and soil disturbance, which they said released less carbon dioxide than tilling the soil.

But other researchers dispute the claim that the use of GMO crops and herbicides is better for the climate than organic farming.

Amber Sciligo is the director of science programs for The Organic Center, a nonprofit research organization focused on the environmental and health effects of organic food and farming.

“Organic is climate smart farming and there are a lot of resources out there that present either primary data or collections of existing data to support this claim,” Sciligo told The Epoch Times.

“The manufacturing, distribution, and application of synthetic ammonia fertilizer is one of the largest contributors to energy consumption and nitrous oxide greenhouse gas emissions. This fertilizer is prohibited in organic.”

Organic soil has 13 percent more total organic matter and 44 percent more stable sequestered carbon, she said.

Although some GMO crops, such as corn, have been developed to reduce the use of chemical sprays and fertilizers, the technology is “wearing off” and creates a secondary drawback for farmers, Sciligo said.

“The expense to purchase and grow the patented seed may not always be returned in crop yield and profit,” she said.

In a 2023 report, the Pesticide Action Network stated that pesticides “contribute to climate change throughout their lifecycle via manufacturing, packaging, transportation, application, and even through environmental degradation and disposal.”

The use of these chemicals creates a “vicious cycle” that ultimately reduces pesticide efficacy and crop resilience and necessitates the use of more chemicals, according to the report.

GMO proponents argue that crops can be engineered to reduce these negative traits, but Sciligo said organic farming has already solved this problem.

“Organic and non-GMO farming helps reduce the use of and exposure to toxic chemicals,” she said, adding that although some GMO crops require fewer chemical applications, the end result is the same. She called it the “dousing of large areas of land with large amounts of pesticides.”

In a 2023 study published in the Journal of Soil and Sediments, the authors concluded that the use of chemical herbicides may have “long-lasting effects on soil microbial biomass and diversity and therefore herbicides should be used with caution as part of an integrated land management plan.”

Last year, Frontiers in Microbiology published a study linking soil biomass and diversity to carbon sequestration. This calls into question the claim that GMOs have higher rates of carbon sequestration, given the chemicals used in production.

GMO corn and soy have been engineered to be drought-tolerant, but crop yields have still suffered setbacks in severely arid conditions.

In a November 2023 study published in Emerald Insight, the authors noted “significant losses” in corn and soy yields because of drought in Argentina, which grows more than 61 million acres of GMO corn and soy crops annually, according to a study published in Frontiers in Bioengineering and Biotechnology.

Blake Beckett of West Central Cooperative sprays a soybean field in Granger, Iowa, on July 11, 2013. Charlie Neibergall/AP Photo

Health Concerns

The majority of food products derived from GMOs are consumed in ultra-processed foods and animal feed, according to a study published in the journal Pediatrics.

Consumption of ultra-processed foods has been associated with an increased risk of cancer, according to a study conducted by the International Agency for Research on Cancer and the University of Vienna, whose findings were published in The Lancet Regional Health.

With regard to whole foods, the U.S. Food and Drug Administration maintains that GMOs are as safe and healthy as their non-GMO counterparts. The agency further states that some genetically modified plants have been engineered to improve their nutritional value.

But validation of public health concerns about GMO consumption emerges in one specific facet: the use of potentially cancer-causing chemicals in their production. With many crops engineered to tolerate large doses of chemical applications, it has become an inseparable part of the conversation on health.

In a meta-analysis published in the journal Mutation Research, researchers observed a 41 percent increased risk of non-Hodgkin lymphoma developing in people with high exposure to glyphosate-based herbicides, which are widely used with GMO crops.

Glyphosate is an active ingredient in the popular weed-killer brand Roundup, but it is also present in many commercial herbicides.

Similar health issues have been identified with the use of pesticides. Prenatal and infant exposure to pesticides is correlated with a higher risk of autism spectrum disorder in children, according to a paper published in the BMJ (formerly the British Medical Journal).

The majority of genetically engineered crops are designed for heavy chemical tolerance. In the first 20 years of GMO use in agriculture, herbicide application increased by 15 times, according to the Non-GMO Project.

“The use of these herbicides has led to a decline in native plants, which has downstream effects on biodiversity. Additionally, the overuse of herbicides has led to the emergence of pesticide-resistant ’superweeds’ and ’superbugs,' which can only be killed by spraying more toxic chemicals,” the organization states on its website.

Sciligo is concerned about the potential contamination of food from GMOs and non-organic farming.

“When GM crops are used in conjunction with toxic sprays, there’s a realized risk of contamination of the final product that we eat with residues of pesticides,” she said. “Sublethal, long-term exposure to pesticides is something that we should be worried about. Many fresh ingredients coming from conventional [agriculture] are testing positive for agricultural chemicals.”

Scaling Up

One of the major arguments in favor of GMO use in conventional farming is tied to the numbers.

Dan Blaustein-Rejto, from the nonprofit Breakthrough Institute, wrote in a 2017 report that the sheer volume of food crops needed to keep the U.S. population fed would present significant hurdles for organic farming, such as the need for more land and therefore more deforestation.

But some organic farming supporters say they’re ready for scaling challenges.

“Ag technology is no stranger to organic,” Sciligo said. “In fact, because organic farmers have such a restricted toolbox, they’ve had to become very innovative to continue to increase yield and counter the increased labor requirements that come with manually managing pests and weeds.

“Overall, the practices organic farms use generate better yields over time as their ecosystem functions and services build up. This closes the yield gap that so many are concerned about.”

Yield gaps between organic and conventional farming are highly dependent on the type of crop, soil management practices, and investment into research and development, according to Sciligo.

“The application of organic management practices that improve soil health, such as multi-cropping and crop rotations, have reduced the yield gap to less than 10 percent for many crops,” she said.

No genetically modified traits of any kind are permitted under the current model of U.S. organic farming, according to the USDA.

However, in a 2021 paper published in the journal Nutrition Today, researchers challenged the idea that GMO crops can’t also be organic.

Sciligo cautioned against believing all of the claims about genetic engineering.

“The promises of GMs can be enticing,” she said. “They claim to cure diseases, protect against pests, and increase yields and nutrition. But so far the promises haven’t come without a great deal of consequences.”