Researchers discover new way to store carbon dioxide absorbed by plants at the bottom of the Black Sea

Researchers have found a new way to store thousands of years of carbon dioxide and prevent its release into the atmosphere, boosting efforts to limit greenhouse gas emissions from multiple sources.

Carbon sequestration, or carbon capture, generally involves extracting carbon from the atmosphere, compressing it, and storing it underground.

But Israeli climate change solutions company Rewind took inspiration from Earth’s natural processes for an innovative carbon storage solution, Rewind CEO Ram Amar told ABC News.

The method involves taking plants and other biomass that have absorbed significant amounts of carbon and storing them at the bottom of the Black Sea, Amar explained.

“We look to nature, because the best machine for capturing carbon dioxide from the air today is plants,” Amar said.

Plants, especially trees, are known for their ability to capture and store carbon dioxide. During photosynthesis, plants absorb carbon dioxide from the air, allowing them to grow. Then, when they die and decompose, they release the carbon into the air, Amar explained.

The researchers hypothesized that if they could preserve the balance of the amount of carbon released when plants die, they could achieve a net negative effect of putting carbon back into the atmosphere, Amar said.

Rewind takes existing plant materials that have been burned or not put to good use and ships them to the coast, sinking them to the bottom of the Black Sea.

The Black Sea is “the best place in the world” to store carbon-dense biomass for several reasons, Amar said. The geological shape of the closed sea prevents oxygen from mixing from the upper layers, where photosynthesis occurs and oxygen comes from the air, with the deeper layers.

The lack of oxygen creates a perfect conservation environment for plants, which will prevent them from decomposing and releasing carbon dioxide into the atmosphere, experts said.

What initially attracted Amar to the Black Sea were several wooden shipwrecks lying on the sea floor that had been “frozen in time for over 2,000 years,” he said.

“We thought that if we take the remnant plants and throw them at the bottom of the Black Sea, they will stay out of the air for thousands of years,” he said. “It checks the box for permanence with a natural solution.”

Additionally, as the Black Sea is surrounded by the breadbasket of Europe, countries like Ukraine, Bulgaria and Romania that grow hundreds of millions of tons of agricultural produce per year, there remains about a gigatonne of biomass residual each year, when adding the amount of wood products from the region’s natural and managed forests, Amar said.

Woody plants, such as trees, are the best biomass to use in this process because they capture carbon quickly and are very stable in water, Amar said. Other agricultural remains, such as sunflower stalks harvested for their seeds and oil, are also suitable for this carbon storage method, Amar said.

The plants are tested to determine how much carbon they contain and whether they contain harmful chemicals such as fertilizers and pesticides before being transported and sunk into the sea, Amar explained.

Amar and his team estimated that, if scaled up, this method of carbon storage could remove 1 billion tons of carbon dioxide from the atmosphere per year.

In 2022, the world collectively emitted around 36.6 billion tonnes of carbon dioxide, according to the Global Carbon Budget. The United Nations Intergovernmental Panel on Climate Change announced last year that carbon removal is essential to mitigating climate change.

While around 2 billion tonnes of carbon are removed from the atmosphere each year through carbon capture, the target should be 10 billion tonnes of removal per year to meet urgent net-zero emissions targets, according to the IPCC.

While carbon capture has become a viable solution to mitigating climate change, one of the biggest challenges lies in the amount of energy required to filter CO2 from the air, as well as the cost of infrastructure and operations , according to experts.

In August, the U.S. Department of Energy announced it would award up to $1.2 billion to two projects dedicated to direct air capture, the largest investment ever in technical carbon removal .

Last year, the Department of Energy pledged $2.6 billion in funding for the Carbon Capture Demonstration Projects program, which aims to create storage technologies and infrastructure in major industrial sources carbon dioxide, such as cement, pulp and paper, iron and steel and chemical production facilities. .