Reengineering Life

The Gene-Edited Corn, Cows, and Potatoes That Could Curb Climate Change

Gene-edited foods hold great potential, but the public must accept them first

Photo Illustration, Photo source: Sean Gallup/Getty Images

Reengineering Life is a series from Future Human about the astonishing ways genetic technology is changing humanity and the world around us.

Nearly 200 nations signed on to the Paris Agreement in 2016, pledging to reduce their countries’ greenhouse gas emissions. By now, it’s well known that greenhouse gases emitted through human activity trap heat and warm the Earth’s surface. To curb emissions, many countries are shifting to cleaner forms of power, like solar and wind, and providing incentives for electric cars.

But a new report suggests a somewhat surprising strategy for helping to reduce emissions: editing the genes of plants and animals.

“I think that everybody but a few science-fiction writers have underestimated the extent to which this is going to transform human activity and the relationship between humans and environment,” said Val Giddings, PhD, a senior fellow at the Information Technology and Innovation Foundation, the nonprofit public policy think tank that released the report. Speaking during a September 15 panel discussion about the report, Giddings said gene editing has the potential to help remove more carbon from the atmosphere, cut food waste, and slash emissions from livestock.

One way gene editing could help the climate is by improving plant biology itself. Specifically, it could enhance photosynthesis — the process plants use to convert energy from sunlight into sugar and oxygen. In this process, plants consume carbon dioxide, the most abundant greenhouse gas. Currently, forests and other land vegetation remove about 30% of manmade carbon dioxide emissions from the atmosphere during photosynthesis.

With gene editing, plants could potentially remove more. Most plants harness only about 1% to 2% of the light that lands on them, according to the report, but scientists think their maximum capacity is actually around 12%. Gene editing could be used to boost that efficiency to make plants that can suck up more carbon from the atmosphere.

“If you can improve the efficiency with which plants extract sunlight and convert that into carbohydrates, the potential there is enormous,” Giddings said during the panel discussion.

Gene editing could also be deployed to make trees grow faster and to expand plants’ root systems — both of which could boost their ability to absorb carbon. Older, more mature trees in established forests capture far more carbon than younger trees, as do plants with deeper and more extensive roots. More research is needed before gene editing could be used in this way, the authors caution, because the genetics of plant roots aren’t well understood yet.

Gene editing could also help curb emissions generated by the agriculture industry, especially in developing countries. While in the United States, agriculture at about 10% was the smallest contributor to overall greenhouse gas emissions in 2018 — the largest contributor was transportation at 28% followed by electricity at 27% — agriculture accounts for a much greater portion of emissions in economically developing countries.

In particular, gene editing could be used to help cut down on food waste in agriculture. An estimated one-third of the world’s food is lost or wasted every year, and some of that food is lost before it even gets to the grocery store. For instance, corn yields in Iowa could be cut in half this year because of a long-lived windstorm called a derecho that swept through the state and flattened crops in August.

Scientists with Bayer Crop Science are altering the genes of corn in an effort to cut down on crop loss, said Scott Knight, PhD, who heads the company’s gene-editing efforts, at the panel. Shorter corn — corn that’s closer to the ground — would be more resistant to damage from wind and rainstorms, he said.

In 2019, Bayer introduced short-stature corn made with traditional genetic engineering, and recently the company has successfully used gene editing to make it. Whereas conventional corn grows to between nine and 11 feet tall, short corn reaches a maximum of about seven feet, and it has a thicker stalk to prevent snapping, too. Knight added that the farmers he’s talked to seem excited about using gene editing to address problems like crop loss.

Gene editing differs from traditional genetic modification in a key way: Gene editing seeks to tweak a plant or animal’s own DNA. By contrast, traditional genetic engineering involves mixing DNA from more than one organism. Scientists hope this distinction makes gene-edited foods more palatable to consumers who are turned off by GMOs.

Gene editing could also be used to prevent food waste that happens after crops are harvested. Tons of fruit and vegetables are wasted every year because of browning and bruising, and when they are dumped in landfills, they rot and release methane, which is an even more potent major greenhouse gas than carbon dioxide.

In North America alone, an estimated 400 million pounds of potatoes are discarded annually due to bruising. The Idaho-based potato processing company J.R. Simplot already sells potatoes that are genetically engineered to resist bruising and browning, and it’s now using gene editing to introduce these traits more efficiently.

The majority of greenhouse gas emissions in agriculture, however, come from raising livestock. Gene editing could be used to make cows produce less methane because it’s now known that the amount of methane a cow produces is heavily influenced by its genetic makeup. Gene editing has already been used to make hornless cattle and cows that have more male offspring. Engineering them to produce less methane could be next.

Gene editing has the potential to make more sustainable foods, but whether the public is open to it is another story. Despite the overwhelming scientific consensus that genetically modified foods are safe for human consumption, public resistance to GMOs has reached a head in recent years.

Minnesota-based Calyxt has the first and only gene-edited food product on the U.S. market: a type of soybean oil with a longer shelf life and no trans fats. But consumers can’t buy it yet; for now, it’s only used in restaurants. Several other companies, including Pairwise Plants, are also working on gene-edited foods.

Most of the advancements the report authors envision don’t exist yet, and it will be years before they do. To get there, the report recommends that the U.S. government reduce regulatory hurdles on gene-edited plants and animals, increase investment in research and development for gene-editing technology, and provide incentives to researchers and companies to develop gene-edited climate solutions.

In the meantime, scientists and the companies developing gene-edited crops and livestock will need to convince a skeptical public that these foods are safe and healthy and won’t end up having negative consequences for the environment. While we shouldn’t count on gene-edited plants and animals to solve the climate crisis, they could eventually play a role in keeping global emissions at bay. As the climate crisis worsens, shoppers may need to keep an open mind when gene-edited foods finally hit grocery store shelves.

Former staff writer at Medium, where I covered biotech, genetics, and Covid-19 for OneZero, Future Human, Elemental, and the Coronavirus Blog.

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