Enhanced rock weathering, a concept rooted in geological science, is making its foray into the agricultural sector, promising to revolutionize how we approach carbon removal. Hans Holtan, a seasoned expert in agricultural biologicals, co-founded Syntopa in 2023 to harness this potential. “I think for biologicals in ag, the emphasis hasn’t been on rock weathering because there hasn’t been a recognition of the connection to carbon removal,” Holtan explains. “It hasn’t been very long that we’ve had carbon credits and a substantial market that investors feel like pursuing.”
Syntopa recently secured a $575,000 pre-seed round from Ponderosa Ventures to develop microbial products aimed at accelerating enhanced rock weathering. This technique involves speeding up the natural process of rock weathering, which captures and sequesters carbon dioxide from the atmosphere. By crushing rocks to increase their surface area, the weathering process is expedited, allowing for more efficient carbon capture.
Holtan sees this as a pivotal moment for both agriculture and climate change mitigation. “This is really our opportunity to start to de-risk the enhanced rock weathering concept from a technical and commercial point of view,” he tells AgFunderNews. “We’ll pretty rapidly be moving towards additional funding to really scale up the research and development to get first products to market by 2027.”
Holtan’s journey in agriculture has been extensive. With a PhD in plant genetics from Berkeley and years of experience at Mendel Biotechnology, Bayer, and Koch, he has a deep understanding of the complexities of agricultural systems. His work at Koch Biologics involved developing nutrient use efficiency for biologicals, providing him with firsthand experience in the challenges and potential of these products. “Even though our products worked and our platform was successful, it was a tough sell for the sales team, which was really used to selling commodity goods,” he notes.
At Zymergen, a biotech company acquired by Ginkgo Bioworks in 2022, Holtan saw the power of synthetic biology and its potential to enhance microbial capabilities. This experience inspired him to start Syntopa, bringing along talent and advanced methodologies to create products that address the urgent needs of the agricultural sector.
Enhanced rock weathering leverages Earth’s natural cycle of inorganic carbon, where carbonic acid reacts with igneous rocks like basalt to sequester CO2. This process, which naturally sequesters over a gigaton of CO2 annually, can be accelerated by grinding the rock into dust, increasing its surface area for reaction. “Earth scientists have known about enhanced rock weathering for a very long time, and our climate models are based on this natural part of the cycle,” Holtan explains. “The ability to increase this process substantially by reducing the particle size is also very sound, clear science.”
However, the practical application of enhanced rock weathering presents challenges. Basalt, a common mafic rock, is safe for agricultural use but takes 10 to 20 years to weather in the ground. With international agreements like the Paris Agreement aiming for substantial carbon removal, the slow pace of natural weathering is a significant hurdle. “If the process is so slow, and the amount of money that can be made through it is so limited, companies struggle to scale,” Holtan says. “The impact on the farm is limited.”
Syntopa’s approach involves using microbial treatments to accelerate rock weathering. Decades of sporadic research have shown that microbes can significantly speed up this process, sometimes by up to 60-fold in laboratory settings. “I know that this is going to take a lot of intentionality and that there’s huge potential for making sure that enhanced rock weathering works as well as it can on farms,” Holtan emphasizes.
Syntopa aims to solve the complex interrelationship between different cell types, crop types, and existing microbiomes to make enhanced rock weathering a viable solution for agriculture. By doing so, they hope to provide farmers with a reliable method to improve soil health while contributing to global carbon removal efforts.