Researchers have found a new way to store thousands of years’ worth of carbon dioxide and prevent it from being released into the atmosphere, boosting efforts to limit greenhouse gas emissions from various sources.
Carbon sequestration or capture generally involves extracting carbon from the atmosphere, compressing it, and storing it underground.
But Rewind, the Israel-based climate change solutions company, was inspired by the earth’s natural processes to create an innovative carbon storage solution, Ram Amar, CEO of Rewind, told ABC News.
The method involves taking plants and other biomass that has absorbed large amounts of carbon and storing it at the bottom of the Black Sea, Amar said.
“We look to nature, because the best machine today for capturing carbon dioxide from the air is plants,” Amar said.
Plants, especially trees, are known for their ability to capture and store carbon dioxide. As plants photosynthesize, they take in carbon dioxide from the air, allowing them to grow. Then, when they die and decompose, they release the carbon back into the air, Amar said.
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 carbon reentering the atmosphere, Amar said.
Rewind takes existing plant matter that has been burned or unused and sends it to shore, sinking it to the bottom of the Black Sea.
The Black Sea is “the best place in the world” to store carbon-rich biomass for several reasons, Amar said. The geological shape of the closed sea prevents oxygen from the upper layers, where photosynthesis occurs and where oxygen from the air comes from, from mixing with the deeper layers.
The lack of oxygen creates the perfect environment for plant preservation, 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 have been “frozen in time for more than 2,000 years,” he said.
“We think that if we take waste plants and throw them at the bottom of the Black Sea, they will stay out of the air for thousands of years,” he said. “That checks the box for permanence with a natural solution.”
Furthermore, since the Black Sea is surrounded by Europe’s breadbasket, countries like Ukraine, Bulgaria and Romania that grow hundreds of millions of tons of agriculture each year, about a gigatonne of residual biomass remains each year, when combined with the amount of wood products from both natural and managed forests in the region, 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, also qualify for this carbon storage method, Amar said.
The plants are analyzed to determine how much carbon they contain and whether they contain harmful chemicals such as fertilizers and pesticides before they are transported and sunk in the sea, Amar said.
Amar and his team have 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 about 36.6 billion tons of carbon dioxide, according to the Global carbon budget. The United Nations Intergovernmental Panel on Climate Change announced last year that carbon removal is critical to climate change mitigation.
while approximately 2 billion tons of carbon removed of the atmosphere each year through carbon capture, the target should be removing 10 billion tonnes per year to meet urgent net zero targets, according to the IPCC.
While carbon capture has become a viable solution for climate mitigation, one of the biggest challenges is the amount of energy needed to filter CO2 from the air, along with the cost of infrastructure and operations, according to experts.
In August, the US Department of Energy announced it would award up to $1.2 billion to two projects dedicated to direct air capture, the largest investment in engineered carbon removal ever made.
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 of carbon dioxide, such as cement, pulp and paper, iron and steel, and facilities of chemical production.