A team led by Northwestern University has been awarded $5.1 million by the U.S. Department of Energy (DOE) to explore enhanced weathering as a method for carbon dioxide removal from the atmosphere. This approach involves spreading crushed rock on farmland, which could potentially capture billions of tons of CO2 annually and store it long-term.
The project will take place on a farm in Illinois, where researchers will spread crushed limestone to assess its effectiveness in capturing atmospheric CO2. Although farmers already use limestone to manage soil pH and boost crop yields, this study aims to refine these practices for better CO2 drawdown.
Set to begin in January 2025, this initiative is part of a larger $58.5 million DOE investment into carbon-removal technologies. The research will involve data collection from water and soils over two growing seasons with the goal of developing protocols that can be widely adopted by farmers across various regions.
Andrew D. Jacobson, principal investigator and professor at Northwestern’s Weinberg College of Arts and Sciences, noted the growing interest in enhanced rock weathering: “The decarbonization industry is rapidly expanding, and Northwestern is ideally positioned to take a lead role.” He emphasized the team's commitment to rigorous scientific testing.
Jacobson collaborates with other Northwestern professors and partners including Silicate Carbon, an Ireland-based startup, and Frank McDermott from University College Dublin. The project also includes testing other geologic materials like basalt alongside limestone.
Enhanced rock weathering mimics Earth’s natural carbon cycle but accelerates it significantly through mechanical means such as grinding rocks to increase surface area for chemical reactions. This process converts CO2 into stable bicarbonate ions that eventually form solid calcium carbonate.
Brad Sageman from Northwestern explained the aim: “We want to capitalize on the Earth’s natural feedback system...we have to accelerate the process from millennia to decades.”
Maurice Bryson, CEO of Silicate Carbon, expressed optimism about advancing their research with DOE funding: “It gives us the right people, the right resources and a detailed plan.”
Erich Schott of Schott Farms has been using limestone traditionally but sees potential in more frequent applications for enhanced weathering purposes: “If you don’t try different ideas, you will miss any opportunity to learn.”
This study builds on previous efforts funded by Northwestern's Paula M. Trienens Institute for Sustainability and Energy that tested basalt's efficacy inside controlled greenhouse environments at Chicago Botanic Garden.
Bryson concluded on climate change challenges: "So we have to think of new solutions that can help reduce the effects...it’s going to take a lot of work."