New Haven, Conn. — Normally, throwing rocks at a problem isn’t the best idea.
But in the multi-faceted fight to combat climate change, scientists are finding that crushed rocks judiciously applied to farmers’ fields may be a powerful force in removing heat-trapping carbon dioxide (CO2) from the atmosphere and storing it safely for thousands of years.
How powerful is this idea? Powerful enough to win the four-year, $100 million XPRIZE Carbon Removal competition.
On Earth Day, April 22, XPRIZE officials announced that Mati Carbon, a non-profit based in part on the research of Yale geochemist Noah Planavsky, won the competition’s grand prize of $50 million. More than 1,300 groups from 88 countries took part in the competition, which required teams to create and demonstrate a system for pulling CO2 directly from the atmosphere or oceans and durably sequester it. (Another $50 million in prize money will be distributed to other winners.)
Planavsky, a professor of Earth and planetary sciences in Yale’s Faculty of Arts and Sciences (FAS), along with his lab group, developed the methods to track carbon fluxes that Mati Carbon used in pilot programs. A faculty member of the Yale Center for Natural Carbon Capture (YCNCC), he is also head of Mati Carbon’s science advisory board.
In its work, which is focused on the Global South, Mati Carbon uses crushed rocks to drive a chemical reaction that transfers CO2 to a stable form of carbon that can be stored in the ocean and remain for thousands of years. This process, its scientists say, also helps improve soil health for farmers who have limited funds for soil amendments.
“This prize is an affirmation of the importance of focusing on permanent carbon dioxide removal and creating a pathway to scale it that can bring benefits to some of the people most affected by climate change,” said Planavsky.
“The Mati Carbon team has put in a tremendous amount of work. This investment will allow Mati to bring costs down as they scale up their efforts in a meaningful way.”
Mati Carbon uses a process called Enhanced Rock Weathering (ERW) — a core research area being pursued by scientists around the world, including at YCNCC. It involves spreading crushed rocks or silicate minerals over agricultural land to accelerate natural rock weathering.
Mati Carbon’s rock of choice is crushed basalt, which is a volcanic rock rich in silicate minerals.
As it dissolves, a series of chemical reactions removes CO2from the atmosphere. The carbon gradually moves into streams and rivers and later is delivered to deep aquifers or the ocean — where it can be stored durably in stable bicarbonate form for more than 10,000 years.
What’s more, the process adds beneficial nutrients to the soil, in addition to removing CO2.
Mati has ERW projects ongoing in India, Zambia, and Tanzania, working with small farms. Worldwide, the majority of farmers working on one to three hectares of land are increasingly at risk of climate hazards such as extreme heat, drought, and flooding.
Organizers of XPRIZE say a wide range of carbon removal solutions will be required to avert a 6 degree C spike in global temperatures over the next century. According to the International Panel on Climate Change, about 10 gigatonnes (1,000,000,000 tonnes) of net CO2 will have to be removed from the atmosphere annually by 2050 in order to keep global temperature increases under 1.5 or 2 degrees C.
Mati Carbon’s goal is to remove 100 million tonnes (one metric tonne is equal to 1,000 kilograms, or approximately 2,204 pounds) of CO2 by 2040.
“Mati is thrilled to be the Grand Prize winners of the XPRIZE Carbon Removal competition,” said Jacob Jordan, Mati Carbon’s chief science officer. “This recognition validates the hard work of our team, our partnered farmers, and research partners alike.”
Jordan added that Mati Carbon’s relationship with Yale has been invaluable in the nonprofit organization’s efforts. “ERW can do more than just help to mitigate anthropogenic CO2,” he said. “It can increase incomes and food security for folks who are least responsible and most affected by climate change.”
Planavsky agreed. “This is a great example of how university research can be built upon and translated into real action,” he said.
Yale established YCNCC in 2021 — with a transformative gift from FedEx — as a hub for innovative science to better understand natural processes that sequester carbon from the air and store it in the environment. It is part of Yale Planetary Solutions, a university-wide initiative that seeks to find novel solutions to environmental problems such as climate change and biodiversity loss.
“Collaboration and innovation are cornerstones of the FedEx sustainability strategy,” said Karen Ellis, the chief sustainability officer and vice president of environmental affairs at FedEx. “FedEx was instrumental in establishing the YCNCC, recognizing that Yale’s world-class scientific research would help power and equip innovators to develop, test, and grow the vital solutions needed to remove carbon from the atmosphere.
“Mati’s recognition by XPRIZE provides further evidence that enhanced rock weathering is a promising technology that could deliver for both planet and communities at scale,” Ellis said.
Planavsky’s research — along with the work of Peter Raymond, the Oastler Professor of Biogeochemistry at Yale School of the Environment (YSE), James Saiers, the Clifton R. Musser Professor of Hydrology at YSE, and others — has made Yale an “unequivocal leader” in ERW research, said David Bercovici, the Frederick William Beinecke Professor of Geophysics in FAS at Yale and co-director of YCNCC.
“Their work is exactly the sort of real-world, practical science the YCNCC was made for,” Bercovici said.
In addition to Mati Carbon, two other Yale-related teams made the finalist round for XPRIZE Carbon Removal. They were Lithos Carbon, which also was co-founded by Planavsky and uses ERW techniques, and Ebb Carbon, which created a system for storing atmospheric CO2 in seawater and was co-founded by late Yale faculty member Matthew Eisaman.
XPRIZE Carbon Removal finalists were asked to remove 1,000 net metric tonnes of CO2 during the last year of the competition.