Dr. Subhi Salman is a distinguished researcher and consultant who serves as a bridge between high-level soil science and practical, nature-based climate solutions. He currently holds the position of Director of Research and Development at CO₂Trust.earth, where he leads initiatives focused on biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More engineering, enhanced rock weathering, and the development of rigorous MRV (Measurement, Reporting, and Verification) systems. His career is defined by a commitment to transforming agricultural residues into high-value assets that restore soil health while delivering verifiable carbon removal.

Dr. Salman’s academic foundation is deeply rooted in environmental and agricultural research. He earned his PhD in Agricultural and Forestry Research from the Universidad de Santiago de Compostela in Spain, graduating with honors. It was during his doctoral studies that he had his first transformative encounter with biochar, proving that biochar was a practical solution for global soil degradation. With extensive experience overseeing large-scale deployments—including the remediation of 300 tons of biochar at a CO₂Trust demonstration site—Dr. Salman is a vocal advocate for “ground reality” implementation. His work often focuses on circular economy innovations, collaborating with organizations like Zaytounic and Olivine Development Company to transform underutilized waste streams, into high-quality soil amendments.

Looking toward the future, Dr. Salman envisions a “biochar-mature world” where carbon finance is perfectly aligned with agronomic value. He believes the next decade of climate-resilient farming will depend on integrating biochar with regenerative agriculture and enhanced rock weathering to create a unified, scalable carbon removal strategy. By developing affordable and transparent MRV systems, Dr. Salman continues to push the industry toward making biochar a mainstream industrial input and a cornerstone of global sustainability.

Shanthi Prabha: Dr Salman, before we dive into your global work and technical expertise — can you take us back to the beginning? What was your first encounter with biochar, and what sparked your decision to embrace soil carbon science, regenerative agriculture, and nature-based climate solutions?

Dr. Subhi Salman: My journey with biochar began during my doctoral research in Spain, when I was exploring soil amendments for degraded lands. I was struck by how a simple transformation of biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More could yield such profound benefits for soil health and carbon stabilization. That first field trial, where ryegrass yields jumped by over 25%, convinced me that biochar wasn’t just a scientific curiosity — it was a practical solution with global relevance. From that moment, I felt compelled to dedicate my career to soil carbon science and regenerative agriculture. Biochar became the entry point, but the broader vision was always nature-based climate solutions that restore ecosystems while delivering verifiable carbon removal.

Shanthi Prabha:  You’ve worked across Africa, Europe, the Middle East, and North America applying biochar in very different landscapes. What’s the most surprising insight you’ve gained about how biochar behaves across diverse soils and climates?

Dr. Subhi Salman: Working across Africa, Europe, the Middle East, and North America has shown me that biochar is not a “one-size-fits-all” solution. In sandy soils, it acts like a sponge, retaining water and nutrients, while in clay-rich soils it improves structure and aeration. The most surprising insight has been how local climate conditions amplify or dampen biochar’s effects. In drought-prone regions, its water-holding capacity is transformative, while in temperate zones, the microbial interactions often dominate the story.

Shanthi Prabha:  Your research blends biochar systems, enhanced weathering, and regenerative agriculture. How do you see these three approaches integrating into a unified, scalable carbon removal strategy over the next decade?

Dr. Subhi Salman: I see these three approaches as complementary layers of the same carbon management strategy. Regenerative agriculture provides the biological engine—root exudates, microbial activity, and continuous carbon inputs. Biochar offers structural carbon permanence and habitat for those biological processes, while enhanced weathering contributes mineral-based carbon sequestration and nutrient release over longer timescales. Over the next decade, scalability will depend on integrating these tools within existing farming systems rather than deploying them in isolation. When designed together, they can address permanence, additionality, and co-benefits simultaneously, which is essential for credible carbon removal at scale.

Shanthi Prabha:  You often emphasize carbon permanence. From your field and lab experience, what are the biggest misconceptions about long-term carbon stabilization using biochar?

Dr. Subhi Salman: Permanence is indeed a fact when it comes to biochar, but it is not absolute — it depends heavily on the soil type, the feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More used, the pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More temperature, and even factors like carbon content and the H:C ratio. These variables shape how stable the carbon is over time, and they remind us that biochar is not a uniform material but a spectrum of products with different behaviors in the soil. That said, I don’t believe permanence has been studied comprehensively enough across diverse environments. We need more long-term trials in different soils, climates, and with varied feedstocks to truly understand how biochar stabilizes carbon under real-world conditions. Each case should be judged individually, rather than assuming a universal permanence profile. Only then can we move from broad claims to evidence-based confidence in biochar’s role in long-term carbon removal.

Shanthi Prabha:  You’ve overseen large-scale biochar deployments and soil trials. What is one “ground reality” challenge you face in real-world implementation that academic studies often overlook?

Dr. Subhi Salman: One of the biggest projects that I have overseen was in our project and demonstration site where CO₂Trust deployed around 300 tons of biochar for remediation purposes. One challenge that academic studies often underestimate is operational variability. Field conditions are messy—uneven application, inconsistent incorporation depth, farmer constraints, and weather shocks all influence outcomes. These factors rarely appear in controlled experiments, yet they define real-world performance. Another overlooked issue is logistics. Transport, particle size management, and timing relative to cropping cycles can determine whether a biochar project succeeds agronomically and economically. These are not minor details; they are often the difference between adoption and abandonment.

Shanthi Prabha:  With your background in developing MRV systems, what would an ideal, science-rigorous yet farmer-friendly MRV framework look like for biochar carbon credits?

Dr. Subhi Salman: An ideal MRV system would combine scientific rigor with simplicity for farmers. It should integrate soil sampling, remote sensing, and digital reporting, but present results in farmer-friendly dashboards that show both agronomic and carbon outcomes. The framework must balance transparency for certification bodies with usability for practitioners. If farmers see direct value in the data — improved yields, water retention, soil health — they will embrace MRV as a tool, not a burden. Moreover, I think that If the higher MRV cost problem should be solved, so the carbon credits can be accessible.
Part of my Role in CO₂Trust is to be part of that solution to build MRV system that is affordable transparent and can help taking the CDR market a step further.

Shanthi Prabha:  You’ve developed and validated biochar-based and algae-based biofertilizers. Where do you see the future of biochar–biological synergies — combining biochar with microbes, algae, or mineral blends?

Dr. Subhi Salman: The future lies in functional integration rather than simple blending. Biochar can act as a carrier, habitat, and buffer for microbes, algae, and mineral nutrients, but only if the system is designed intentionally. Poorly matched combinations can neutralize benefits rather than enhance them. I see strong potential in biochar-algae systems and biochar-mineral-microbe consortia, especially in degraded or nutrient-poor soils. These synergies can improve nutrient efficiency, biological resilience, and farmer acceptance simultaneously.

Shanthi Prabha:  Many argue that biochar’s biggest bottleneck is not science, but scaling. From your perspective, what is the single most strategic intervention that can unlock global adoption?

Dr. Subhi Salman: The single most strategic intervention is aligning carbon finance with agronomic value. Farmers will not adopt biochar at scale for climate reasons alone—it must improve productivity, resilience, or input efficiency in a measurable way. When carbon markets reward practices that already make agronomic sense, scaling becomes organic rather than forced. Biochar adoption accelerates when it is seen as a soil asset, not a climate obligation.

Shanthi Prabha:  You work extensively on regenerative agriculture. How do you envision biochar reshaping the next generation of climate-resilient farming systems, especially in drought-prone or nutrient-depleted regions?

Dr. Subhi Salman: In drought-prone regions, biochar acts as a water reservoir, reducing crop stress and stabilizing yields. In nutrient-depleted soils, it enhances fertilizer efficiency, making scarce resources go further. I envision biochar as a cornerstone of climate-resilient farming systems, enabling smallholders and large farms alike to withstand shocks while regenerating their soils.

Shanthi Prabha:  As someone deeply involved in circular economy innovations, what feedstock or waste stream do you believe is the most underrated or underutilized for high-value biochar production?

Dr. Subhi Salman: Agricultural residues from mixed cropping systems are still widely underutilized such as (Olive Pomace, wine pomace, vegetables wastes ….etc). These materials are often burned or discarded, yet they offer excellent potential for locally produced, context-specific biochar. I work with Agrophenols, Olivine, P-Vita and Zaytounic to transform this waste into innovative, high-value solutions. Another overlooked stream is organic processing waste—when managed correctly, it can yield high-quality biochar while solving disposal problems. Circularity begins at the feedstock level.

Shanthi Prabha:  Looking 15–20 years ahead, what is your vision for the role of biochar in global carbon markets, soil restoration, and regenerative systems? What would a truly “biochar-mature world” look like?

Dr. Subhi Salman: Biochar is already recognized in carbon markets, but in the next 15–20 years the focus should be on making it more affordable, scalable, and integrated across industries. Beyond agriculture, biochar can play a role in waste management, construction materials, and even energy systems — turning it into a cross‑sector solution rather than a farming niche. A biochar‑mature world would mean lower costs for monitoring, reporting, and verification (MRV) while delivering higher accuracy and value, supported by AI‑driven tools that simplify data collection and certification. Investment would become cheaper and more attractive, with standardized protocols and clear pathways for adoption. In this scenario, biochar is not just a climate solution but a mainstream industrial input, embedded in both carbon markets and everyday economic systems.

Shanthi Prabha:  You’ve already published impactful work and guided multi-site trials. If you could redesign global biochar research priorities, what top three questions would you push to the forefront?

Dr. Subhi Salman: First, I would prioritize long-term, multi-site field studies that explicitly track carbon permanence under real management conditions. Second, I would push for deeper integration between soil biogeochemistry and MRV methodology development. Third, I would elevate farmer-centered research—understanding adoption barriers, management trade-offs, and real economic outcomes. Without that, scientific advances will remain underutilized.

Shanthi Prabha:  A lighter one! If biochar could speak during one of your soil trials, what do you think it would say?

Dr. Subhi Salman: And perhaps it would add: “I am not the solution—I am part of one.”

Shanthi Prabha:  Where should our readers go to follow your work?

Dr. Subhi Salman: My research, would be found on google scholar.
For my achievements and work, they can follow me on LinkedIn.