Start-up hopes that “super” poplars will absorb more CO2

Steven Strauss was skeptical when he first heard about a poplar being bioengineered to absorb more carbon dioxide from the air.

The forest biotechnologist knew that trees are difficult to modify genetically – and that the “tender care” of a laboratory is no substitute for the outside world. When two entrepreneurs asked him to help test the idea, Strauss was intrigued but hesitated.

“If it works, it would be a wonderful thing,” he said at the time. “But typically in agricultural or forestry research, just because it works in the lab or in the greenhouse, [that] tells you nothing.”

Four years later, these entrepreneurs – Maddie Hall and Patrick Mellor – have raised $30 million for Living Carbon, a company that aims to plant between 4 and 5 million cottonwood trees with “photosynthesis-enhanced” seed by spring 2024 . Eventually, the company hopes to enter the carbon offset market, selling credit to companies that need to reach net-zero emissions targets.

One of the field trials is being conducted in a forest at Oregon State University, where Strauss is a distinguished professor of forest biotechnology. Other sites are in the United States, including an abandoned mine site in Pennsylvania with degraded soils.

Co-founders Hall and Mellor hope the trials will prove the taller trees can store up to 27 percent more CO2 than common poplars. The company’s next step will be to show that the CO2 can be stored in lumber and plywood and outlast the poplar’s lifespan, which can be as long as 200 years.

The Department of Energy, which awarded Living Carbon a $500,000 grant in 2021, projected that the company’s approach, if successfully scaled up, could remove billions of tons of CO2 from the atmosphere. Investors have since come forward, including Toyota Ventures and Singapore-based state-owned Temasek.

Lisa Coca, a partner at the Toyota Ventures Climate Fund, said the voluntary carbon credits market could surpass $50 billion by 2030 – but only if a high volume of credits becomes available in the near future. Living Carbon, she argued, could provide credit within the next three to five years.

“Living Carbon’s synthetic biology platform has the potential to bridge the gap between supply and demand by leveraging the powerful combination of proven nature-based carbon sink solutions and genetic engineering to deliver high-quality credit to the market,” said Coca in a recent statement.

The Mona Lisa connection

The poplar is one of the fastest growing trees in the world – and it has a long and interesting history.

Greek and Roman soldiers made shields from the wood. In the US, where poplars are sometimes referred to as poplars or aspens, they are often found in gardens and grow to anywhere from 50 to 160 feet tall. The slender, cone-shaped trees are also increasingly being used in housing, often in the form of plywood.

Leonardo da Vinci chose a panel of poplar wood to paint the Mona Lisa almost 500 years ago.

At Oregon State, Strauss has spent much of his career growing poplars. He first tackled the tree’s bad breath: It emits a chemical called isoprene, which, when mixed with exhaust pollution, can increase the global warming potential of already potent methane.

Then he tamed the active sex life of the poplar. A forest of normal poplars with a cluster of trees producing diverse female flowers and male pollen could produce a spectrum of seedlings sufficient to overwhelm that of a genetically engineered newcomer.

After years of research in Oregon’s 9-acre cottonwood field, Strauss and his colleagues discovered a way to impart “containment traits” to engineered trees that made GM trees distinctive.

Now Strauss is part of Poplar’s biggest experiment. Strauss stressed that he had no investments or shares in the company. It is his interest to “promote what works”.

Recently, a team from Living Carbon joined Strauss students to plant the seeds of what the company calls “super trees.” The team “had a party that drove them into the ground,” Strauss said.

Hall, the CEO of Living Carbon, has expressed high hopes for the project.

“Today, the earth no longer has the ability to fix carbon so quickly. We have distorted the metabolism of our biosphere,” she wrote in a blog post. “And now it’s time for the big inhalation.”

E&E News reprinted with permission from POLITICO, LLC. Copyright 2023. E&E News provides important news for energy and environmental professionals.