A global ban on genetically modified crops (GMOs) would raise food prices and have the environmental impact of adding the equivalent of nearly a billion tons of carbon dioxide to the atmosphere, a study by researchers from Purdue University shows.

The study also points out that if countries that already plant GMOs expanded their use of genetically modified crops to match the rate of GMO planting in the United States, then global greenhouse gas emissions would fall by the equivalent of 0.2 billion tons of carbon dioxide and would allow 0.8 million hectares of cropland (about 2 million acres) to return to forests and pastures.

The researchers used a model to assess the economic and environmental value of GMO crops, agricultural economists found that replacing GMO corn, soybeans and cotton with conventionally bred varieties worldwide would cause a 0.27 to 2.2 percent increase in food costs, depending on the region, with poorer countries hit hardest.

The study, published in the Journal of Environmental Protection (October 27, 2016), states that a ban on GMOs would also trigger negative environmental consequences: The conversion of pastures and forests to cropland – to compensate for conventional crops’ lower productivity – would release substantial amounts of stored carbon to the atmosphere.

“Some of the same groups that want to reduce greenhouse gas emissions also want to ban GMOs. But you can’t have it both ways,” said Wally Tyner, the James and Lois Ackerman Professor of Agricultural Economics. “Planting GMO crops is an effective way for agriculture to lower its carbon footprint.

“It’s quite fine for people to be concerned about GMOs – there’s no scientific basis to those concerns, but that’s their right,” he said. “But the adverse impact on greenhouse gases without GMOs is something that is not widely known. It is important that this element enter into the public conversation.”