The European Union could greatly reduce carbon emissions by embracing genetically engineered crops. If EU countries had grown genetically modified crops in 2017, in total they would have cut greenhouse gas emissions by the equivalent of 33 million tonnes of carbon dioxide that year, according to an analysis.

The reason is that GM crops have higher average yields, meaning less land is needed to produce the same amount of food. “That can reduce clearing of new agricultural land,” says study co-author Emma Kovak at the Breakthrough Institute in California. “And when land is cleared, that carbon storage is lost.”

In fact, according to a 2018 report by the World Resources Institute (WRI), if farm yields remain at today’s levels, most of the world’s remaining forests would have to be cleared to meet estimated food needs in 2050. This would wipe out thousands more species and release enough carbon to warm the world by more than 2°C, even if all other human emissions stopped, it says.

Kovak and her colleagues have now worked out what the change in carbon emission would have been if the adoption rates of five key GM crops – soya bean, maize, cotton, rapeseed and sugar beet – had been as high in Europe as they were in the US in 2017, which has a much more favourable view of genetic engineering.

Read more: Can we really save the planet by making food ‘from air’ without farms?

The team used data from a global metastudy of GM crops and previous studies of land-use change to calculate the 33 million tonnes of CO2 equivalent figure. This is a substantial amount, equivalent to 8 per cent of all the EU’s agricultural greenhouse gas emissions in 2017. For comparison, total global emissions from all human activities are around 100 million tonnes of CO2 per day.

Many people think intensive farming is bad for the environment. If you measure the impact of low-intensity organic farming per area used, it is lower, says Kovak. But per amount of food produced, high-intensity farming has a much lower impact. “The intensification of farming can spare habitat for wildlife,” she says.

Tim Searchinger at Princeton University, one of the authors of the 2018 WRI report, thinks there is more uncertainty about the yield increases from GM crops than the study suggests. However, the overall evidence does point to yield gains. “I think genetic engineering probably can be very useful,” he says.

Luisa Colasimone at the Greenpeace European Unit says genetically engineered crops aren’t a good solution. “GE food means handing over food production to a few companies interested only in profits,” she says. “GE crops increase the use of harmful chemicals.”

Some studies have concluded that GM crops have reduced pesticide use. And the rise of CRISPR gene-editing technology is enabling smaller groups and companies to produce modified crops, says Kovak.

Technologies such as gene editing could produce much more dramatic yield increases in the future. For instance, in 2019, a team boosted tobacco yields by about 40 per cent by fixing a flaw in photosynthesis. This trait is now being engineered into food crops.

Reference:bioRxiv, DOI: 10.1101/2021.02.10.430488