Interview: Eion’s Approach to Research with Alison Marklein and Kelly Tucker

To offer a behind-the-scenes look at how Eion approaches research, we interviewed two of Eion’s former scientists:

Alison Marklein (right) served as Eion’s Senior Scientist, leading fieldwork, theory, and modeling to enhance how Eion practices enhanced rock weathering. She received her PhD in Global Ecology and Biogeochemistry from UC Davis and holds a BA in Computational Biology from Cornell.

Kelly Tucker (left) served as Eion’s Junior Staff Scientist and Chemical Hygiene Officer after studying Plant Sciences at UC Davis. She just wrapped up her time at Eion to head to UC Berkeley to continue researching enhanced rock weathering as a PhD student.


Q: Tell us about your path to becoming a scientist.


I love asking questions nobody knows the answers to. After my PhD, I worked in academia and eventually transitioned to industry because I wanted to see my research applied and focused on solutions.


I studied plant sciences at UC Davis, emphasizing crop breeding and crop production. Once I graduated, I was primarily looking for roles that would help the environment. I ultimately decided to work for Eion because of the team. I love working with female scientists and wanted Alison to be my boss.


Q: What’s it like doing field research at Eion?


I get hands-on with many aspects of a project, including doing fieldwork, writing plans for other partners to run experiments, creating white papers, and representing Eion at different scientific meetings and industry conferences. It’s fast paced and gives me a holistic understanding of how enhanced rock weathering (ERW) works and the nuances of what is happening in the soil. Everything is a learning experience, and it’s fun to gain depth in the variety of topics our work touches.


It varies from day to day. Sometimes my days are physical, working with the soil and being in the field, or building infrastructure for experiments. Other times I work with soil or olivine in the lab, or on my computer writing reports or doing data analysis. It’s super fun because I can be creative and develop experiments that answer essential questions about ERW.


Q. How does Eion approach measurement, reporting, and verification (MRV)?


In this industry, MRV is often used as a shorthand for measuring the carbon removed in a process. But MRV is about a lot more than that. A robust MRV methodology includes measuring and understanding any carbon removal pathway’s environmental and social impacts.

Eion approaches MRV broadly, and that guides our active research into the ecological benefits of ERW, how we can operationalize monitoring practices to prevent environmental harm, and even understanding how we are impacting the communities in which we operate. At Eion, when we talk about MRV, we look at the bigger picture of our impact on the ground, not only how much carbon is removed.


Q. Many organizations in this space rely on forecasts to inform their MRV rather than direct measurement. Why does Eion focus on direct measurement, and how does that shape Eion’s research?


Direct measurement is an underlying ethos of how we work. Using direct measurement in various contexts helps us understand the nuances of how ERW works in practice while monitoring ecosystem impacts. This will lead to a better understanding of locations best suited for ERW and will generally improve deployment decisions.

In practice, it means Eion measures everything we possibly can in our field trials. Enhanced rock weathering is a multi-step process in the early stages of deployment. Getting as much directly measured data as possible helps us finetune and calculate more accurately how the process works—not just how we assume it will work.

An example of this is our approach to directly measuring soil samples. This gives us an accurate picture of how carbon is removed in various soil conditions and allows us to monitor nutrient leaching, plant impacts, and other ecological benefits. This approach of accounting for the entire process and impacts is core to our commitment to responsibly deploy ERW.


Q. Is there any current or recent fieldwork you can tell us more about?


I’ve been focused on olivine performance and how it affects crop output, nutrient imbalances, and yield. This includes research into dissolutions, investigating the mineralogy of particle size fractions of the olivine (how varying fineness of olivine affects weathering), and how different surface area textures can contribute to the dissolution rate. In a series of experiments, I’ve looked into how different feedstocks (particle size, chemical composition) impact the rate of weathering, which will help us better predict the rate of weathering in the field.

Another focus of Eion’s olivine research is ensuring that our process has no harmful effects on the ecosystem, soil system, or crops. Ultimately we’re building the evidence that our olivine material, CarbonLock, is a safe and reliable product that performs the same as or better than the agricultural lime (ag lime) farmers already use—and it’s a very predictable, fast-acting material for carbon removal.

There’s a lot to be unpacked, and it’s something that the ERW field will be talking about for the next 10-20 years, so I’m very excited to be at the forefront of this niche intersection of geology and carbon removal.


Kelly and I set up one set of tests in the field to understand what is leaving the ecosystem via groundwater. We created lysimeters (a PVC pipe system to collect and store soil water). The test mimicked the ERW process by placing olivine and soil on a mesh covering at the top and applying water to dissolve the olivine and form the bicarbonate, which then moved into the soil water captured in our lysimeters. We tested the soil water samples to calculate how nutrients such as magnesium and nitrogen are flushed in the process.

Another recent field trial sampled crop tissues (leaves, roots, grain) to measure nutrients in the plant and help us understand how silicate rocks change nutrient uptake in plants. In addition, some of the magnesium goes into the plant rather than binding to and removing carbon dioxide from the soil. This research into plant uptake helps us adjust our calculations and ensure we’re not overcounting the carbon removed in our process.

These field trials aren’t setups we would necessarily deploy commercially, but are examples of how Eion continuously validates calculations and deepens our understanding of how ERW works on the ground.


Q. One final question: can you tell us your favorite part about working at Eion?


We have a solid, cohesive team. Our leaders have invested a lot into building a strong cultural foundation at Eion, which speaks volumes about the company’s long-term mindset overall. If we’re going to do this work for the next 10, 20, 100 years, having a strong culture is just as fundamental as great innovation.


Our team intentionally builds supportive and inclusive relationships, and this is seen in how much we prioritize collaboration across the ERW industry. We see everyone in this space as colleagues and genuinely believe we can only build this category together. At the end of the day, even if Eion does everything amazingly well, we can’t do any of this alone.


Want to hear more from the team at Eion? Our cofounder and Chief Science Officer Elliot Chang sat down to discuss the importance of measurement, reporting, and verification (MRV) for enhanced rock weathering, and the multitude of ways that Eion is building trust in our direct measurement approach. Read the interview>>