Climate Action Starts from the Ground Up: The Role of Soil

Dr Khalid Mahmood, Head Partnerships & Development BSSS

We tend to look up when we think about climate change—towards smokestacks, jet engines, and the carbon accumulating in the atmosphere. Yet one of the most powerful, scalable, and immediate climate solutions lies directly beneath our feet. Soils store around 2,500 gigatonnes of carbon—more than three times the amount in the atmosphere and four times that held in all living vegetation. They also support 95% of global food production, filter and store water, and are home to more than a quarter of the world’s biodiversity. Protecting and restoring healthy soils is therefore fundamental to achieving net zero, strengthening climate resilience, enhancing biodiversity, and ensuring long-term food security.

That was the unifying theme of Climate Action Starts from the Ground Up: The Role of Soil, a webinar hosted by the British Society of Soil Science (BSSS) on 22 June 2026 as part of London Climate Action Week.

The session brought together a global panel of soil scientists and policy leaders around one clear message: there is no decarbonisation, no climate resilience, no food security, no biodiversity recovery, and no water security without healthy soils. It was chaired by Dr Lizzie Sagoo, President-Elect of BSSS, with audience questions facilitated by Dr Khalid Mahmood of the BSSS partnerships team. A recording is available on the BSSS YouTube channel.

The panel

• Prof Pete Smith, Professor of Soils and Global Change, University of Aberdeen
• Dr Elen Lemaître-Curri, Executive Secretary, International “4 per 1000” Initiative
• Dr Thorunn Wolfram, Secretary, FAO Global Soil Partnership
• Prof Dr Abdul Wakeel, Professor of Soil and Environmental Sciences, University of Agriculture, Faisalabad
• Dr Leigh Winowiecki, Global Research Lead on Soil and Land Health, CIFOR-ICRAF, and co-founder of the Coalition of Action for Soil Health (CA4SH)
• Chair: Dr Lizzie Sagoo, BSSS President-Elect
• Co-Chair and Q&A facilitator: Dr Khalid Mahmood, BSSS Partnerships

Why soil belongs at the centre of climate action

Opening the session, Dr Lizzie Sagoo set out why soil is so often missing from climate conversations despite sitting at the heart of many of the world’s most pressing challenges. Soil is the foundation that connects climate, food, water, biodiversity, infrastructure, and human wellbeing. It regulates water, cycles nutrients, stores vast amounts of carbon, supports resilient food systems, and underpins thriving ecosystems.

Dr Sagoo emphasised that healthy soils are not simply an environmental asset but a form of critical natural infrastructure. Investing in soil health can help reduce greenhouse gas emissions, enhance carbon sequestration, improve resilience to droughts and floods, strengthen food security, improve air quality and protect biodiversity, while also delivering economic benefits for farmers, businesses, and society. She highlighted that achieving climate and nature targets will require soils to be recognised alongside energy, transport, and industry as a strategic national priority, supported by science, innovation, policy, and long-term investment.

Soils: part of the problem, and part of the solution

Prof Pete Smith opened the scientific discussion with a balanced perspective, presenting soils as both part of the climate challenge and one of its most promising solutions.

On the challenge side, he explained that soil-related emissions contribute around 15% of human-induced climate warming. More than half of global anthropogenic nitrous oxide (N₂O) emissions originate from agricultural soils, largely driven by fertiliser use and land management. Flooded paddy rice soils account for around 10% of global methane (CH₄) emissions, while soils contribute less than 1% of anthropogenic carbon dioxide (CO₂) emissions, with fossil fuel combustion remaining by far the dominant source of CO₂.

However, Prof Smith stressed that these figures also illustrate the enormous opportunity. The way soils are managed determines whether they function as a net source or a net sink of greenhouse gases. Adopting climate-smart soil management practices—including increasing soil organic matter, reducing soil disturbance, improving nutrient management, and restoring degraded land—can simultaneously reduce emissions, sequester carbon, and improve resilience to climate extremes.

Beyond climate mitigation, healthier soils deliver multiple co-benefits. Increased soil organic matter improves soil structure, enhances water infiltration and retention, supports biodiversity, boosts nutrient cycling, and increases crop productivity while reducing year-to-year variability in yields under droughts and other climate stresses. Prof Smith concluded by reminding the audience that healthy soils underpin every one of the United Nations Sustainable Development Goals, making soil stewardship one of the most effective cross-cutting investments for climate action, food security, ecosystem restoration, and sustainable development.

The soil carbon opportunity, and its hard problems

Soil carbon is one of the most talked-about climate solutions, and Prof Smith set out both the scale of the prize and the reasons for caution.

The opportunity is real and large:

• The global technical potential for soil organic carbon sequestration is around 5 gigatonnes of carbon dioxide equivalent per year, roughly 10 percent of current annual global emissions of about 50 gigatonnes.
• The economic potential is lower, in the range of 1.5 to 2.6 gigatonnes, because some practices are costly.
• Around 25 percent of the mitigation potential from natural climate solutions occurs in the soil itself.

There is also a restoration story behind these numbers. Over the past 12,000 years of human land use, soils have lost an estimated 133 gigatonnes of carbon. A meaningful share of the opportunity is simply about putting some of that carbon back, while still keeping land in productive use to feed a growing population.

But Prof Smith was candid that soil carbon is not a magic bullet, and he named three challenges that anyone working in this space has to confront:

• Reversibility. Unlike carbon locked into geological storage, carbon gained in soil can be lost again. Stop the good management practice, revert to the old one, and the carbon returns to the atmosphere.
• Saturation. Soils have a finite carrying capacity. As mineral surfaces and aggregates fill up, the amount of carbon a soil can take in each year shrinks, until it reaches an equilibrium. Even then, the good practice must continue just to hold what has been gained.
• Permanence and accounting. Because the gains are slow and can be undone, soil carbon needs long-term commitment and credible verification to be trusted by policymakers and investors.

Why measurement is the missing link

A common theme running through every presentation was the critical importance of Monitoring, Reporting and Verification (MRV). While the potential of soils to deliver climate mitigation is widely recognised, unlocking that potential depends on the ability to measure changes in soil carbon accurately, consistently, and at scale.

Prof Pete Smith illustrated the challenge with a simple comparison. When a tree grows, its carbon can be estimated by measuring its height and trunk diameter. Soil carbon, however, is invisible. Measuring changes requires carefully designed field sampling, laboratory analysis, long-term monitoring, remote sensing, and robust modelling, all integrated within transparent and scientifically credible MRV systems. The science has advanced significantly, but internationally recognised, end-to-end systems that provide confidence to policymakers, investors, supply chains, and carbon markets are still evolving.

Several speakers demonstrated how this challenge is being addressed through international collaboration and innovation.

The “4 per 1000” Initiative, for which Prof Smith was a founding member of the Scientific and Technical Committee, has developed internationally recognised guidance and indicators for monitoring changes in soil organic carbon, helping establish a common scientific framework for soil carbon accounting.

Building on this work, the FAO’s RECSOIL initiative provides a practical mechanism for scaling sustainable soil management while supporting robust MRV. RECSOIL aims to prevent further losses of soil organic carbon, increase carbon stocks in agricultural soils, improve farmers’ livelihoods and food security, and contribute to climate change mitigation through verified carbon sequestration.

Meanwhile, CA4SH and CIFOR-ICRAF demonstrated how long-term, landscape-scale monitoring can be implemented in practice. Over the past two decades, they have established hundreds of georeferenced monitoring sites across 46 countries, creating one of the world’s largest harmonised datasets for tracking changes in soil health and soil organic carbon over time.

The discussion also highlighted the growing role of digital technologies. Advances in Earth observation, artificial intelligence, digital soil mapping, geospatial modelling, and in-field sensors are making soil monitoring faster, more cost-effective, and increasingly scalable. However, speakers emphasised that these technologies complement rather than replace rigorous field measurements, with high-quality ground data remaining essential for calibration and verification.

The overarching message was clear: the future credibility of soil carbon markets, corporate climate claims, and nature-based solutions will depend on trusted, transparent, and scientifically robust MRV systems. Without reliable measurement, soil carbon cannot become a bankable climate asset; with it, soils can become one of the most powerful and credible tools for delivering net zero, supporting resilient agriculture, and restoring natural capital.

Biochar: a stable carbon store with co-benefits

Biochar attracted considerable interest during the discussion. Prof Pete Smith explained that biochar is produced by heating organic biomass under low-oxygen conditions through a process known as pyrolysis. This converts plant material into a highly stable form of carbon that can remain in soils for decades, and in many cases centuries, providing long-term carbon storage.

Unlike many soil carbon management practices, where stored carbon can be lost if land management changes, biochar offers a more durable carbon sink while delivering a range of additional environmental and agricultural benefits.

These include:

• Long-term carbon sequestration, locking atmospheric carbon into a highly stable form.
• Enhanced soil carbon storage, as biochar provides surfaces that encourage the accumulation and protection of native soil organic matter, creating a dual carbon benefit.
• Improved nutrient retention, reducing nutrient losses and increasing fertiliser use efficiency through its high surface area and cation exchange capacity.
• Lower greenhouse gas emissions, with evidence showing reductions in nitrous oxide and methane emissions under suitable soil and management conditions.
• Improved soil physical properties, including greater water-holding capacity, better soil structure, and increased resilience during drought.
• Renewable energy generation, as the pyrolysis process can simultaneously produce heat and bioenergy, supporting a circular bioeconomy.

However, Prof Smith stressed that the climate benefits of biochar depend fundamentally on the sustainability of the feedstock. Producing biochar from purpose-grown biomass or harvested forests can undermine its environmental value. Instead, the greatest benefits arise from converting agricultural residues, forestry by-products, manure, and other organic wastes that might otherwise be burned, left to decompose, or disposed of, thereby transforming waste streams into valuable soil amendments while avoiding additional emissions.

He also highlighted the importance of quality assurance and monitoring. Feedstock composition influences the chemical properties, carbon stability, nutrient content, and potential contaminants within biochar. Robust standards, certification, and traceability are therefore essential to ensure environmental integrity and maintain confidence in carbon markets.

Although biochar has been adopted at significant scale in countries such as China and is gaining momentum globally, its application across Europe remains relatively limited.

Zero tillage and the case for living cover

A question on zero-tillage wheat and maize systems prompted a practical discussion on balancing soil carbon sequestration with productive farming. While volunteer grasses and weeds can increase biomass inputs and contribute additional root carbon to the soil, they also compete with crops for light, water, and nutrients, potentially reducing yields.

Prof Pete Smith emphasised that the solution lies in better system design rather than accepting a trade-off between productivity and soil health. One promising approach is under-sowing cereal crops with companion species, particularly legumes such as red clover. These living covers help suppress weeds, protect the soil surface, improve biodiversity, and naturally fix atmospheric nitrogen, reducing reliance on synthetic fertilisers while increasing soil organic matter.

The discussion reinforced a broader principle of regenerative agriculture: maintaining living roots in the soil for as much of the year as possible. Continuous ground cover supports soil biology, reduces erosion, improves soil structure and water infiltration, enhances nutrient cycling, and increases resilience to drought and heavy rainfall.

However, Prof Smith cautioned against a one-size-fits-all approach. The most suitable companion crops depend on local climate, soil type, cropping systems, and management objectives. Practices that perform well in one region may not be appropriate elsewhere. This underlines the vital role of local advisers, extension services, and soil scientists in tailoring regenerative practices to individual farming systems and translating scientific knowledge into practical, farm-scale solutions.

Smallholder farmers and the methane challenge in rice

Prof Dr Abdul Wakeel grounded the discussion in the lived realities of smallholder farmers, particularly across South Asia, where rice is both a dietary staple and a critical livelihood crop. While rice production cannot simply be reduced or replaced, he highlighted that flooded paddy systems are among the largest agricultural sources of methane emissions globally.

Rice is cultivated on approximately 165 million hectares worldwide, generating an estimated 30–50 million tonnes of methane (CH₄) annually—around 10% of total human-caused methane emissions. On average, flooded rice fields emit 180–300 kg CH₄ per hectare per year, equivalent to roughly 5–8 tonnes CO₂e per hectare. However, improved water management practices such as Alternate Wetting and Drying (AWD) can reduce methane emissions by 30–70%, often without yield penalties when properly implemented.

Prof Wakeel noted that decades of research have explored alternatives to continuous flooding, including direct-seeded rice, aerobic rice systems, and AWD. Among these, AWD stands out not because it is the most technologically advanced, but because it is practical, scalable, and farmer friendly.

AWD works by allowing paddies to periodically dry down before re-flooding, reducing anaerobic conditions that drive methane formation while also lowering irrigation demand. Its adoption is made more accessible through a simple yet effective tool: a perforated field water tube inserted into the soil, which allows farmers to visually monitor water depth below the surface and decide when to irrigate again. This transforms a scientific protocol into an intuitive, on-farm decision-making tool.

Momentum for AWD is increasingly being supported through climate finance mechanisms and large-scale programmes:

• AWD is already recognised under Gold Standard carbon credit methodologies, enabling verified emission reductions to generate carbon finance.
• Prof Wakeel’s team is currently working across approximately 60,000 acres of rice systems in Pakistan, supporting AWD implementation linked to carbon crediting frameworks.
• An Asian Development Bank–funded programme is generating evidence across eight additional major crops, aiming to expand climate finance mechanisms and strengthen incentives for farmers to adopt low-emission practices.

Despite this progress, Prof Wakeel highlighted a persistent challenge: the gap between science and scale. The technical solutions are well established, but widespread adoption depends on aligning policy support, investment mechanisms, and farmer incentives. For many farmers, particularly smallholders operating on tight margins, the decision to change practices must be both economically viable and operationally simple.

Soil health and the balanced use of fertiliser

A series of audience questions on fertiliser use highlighted how closely soil health, nutrient efficiency, and climate outcomes are interconnected.

Prof Abdul Wakeel explained that over-reliance on synthetic fertilisers has contributed to a gradual decline in soil health in many farming systems. Despite rising application rates, nitrogen use efficiency (NUE) has been falling, meaning that each additional unit of fertiliser delivers diminishing returns in crop uptake. He also noted that mineral fertilisers supply only a narrow range of nutrients, which can lead to deficiencies in micronutrients and contribute to “hidden hunger” in both soils and food systems.

To address this, he advocated a shift towards more integrated, nature-based approaches. These include converting livestock manure, poultry waste, and crop residues into biogas, thereby displacing fossil fuel use, while returning digestate and residues back to soils to rebuild soil organic matter. He also highlighted the targeted use of efficiency-enhancing tools such as nitrification inhibitors and neem-coated urea. The central principle, he emphasised, is that healthier soils improve nitrogen use efficiency both directly—through better nutrient cycling—and indirectly, by supporting a more diverse and functioning soil biological system capable of supplying a wider range of nutrients.

Prof Pete Smith added important nuance regarding the relationship between fertiliser use and soil carbon dynamics. He noted that fertiliser can have both positive and negative effects. On one hand, improved crop growth increases root biomass and organic inputs to soil, enhancing carbon returns. On the other hand, added mineral nitrogen can stimulate microbial activity that accelerates the decomposition of existing soil organic matter. The net effect depends strongly on soil type, climate, management practices, and cropping system. As he summarised, there is no universal outcome—context determines direction.

Dr Leigh Winowiecki reframed the discussion at the intersection of policy, economics, and development. She highlighted that approximately 60% of fertiliser-related greenhouse gas emissions arise from application rather than production, meaning that improving on-farm efficiency is a critical climate mitigation strategy. Strengthening soil health is therefore not only an agronomic goal but also a direct emissions reduction pathway.

She also pointed to evidence from World Bank programmes exploring the repurposing of agricultural subsidies towards soil health investments. In some regions, such as Malawi, long-term soil degradation has reduced the responsiveness of soils to fertiliser inputs, creating a cycle of declining productivity and increasing input dependence. The emerging policy shift, she noted, is to move away from viewing fertiliser as the primary solution, and instead to recognise soil health as the foundational asset that determines whether inputs are effective, efficient, and sustainable.

Translating soil science into global action

A strong overarching theme across the policy and partnership contributions was the urgent need to move from scientific knowledge to coordinated global action on soils.

Dr Elen Lemaître-Curri reflected on the 10-year journey of the “4 per 1000” Initiative, launched at COP21 in Paris to reposition soils as a central climate solution. What began as a coalition of around 160 signatories has now expanded to nearly 900 organisations across more than 100 countries, spanning research institutions, NGOs, civil society organisations, and private sector actors. She highlighted the growing emergence of multi-stakeholder partnerships focused on supply chain resilience, blended public–private finance, and integrated crop–livestock systems. Recent volatility in fertiliser markets, she noted, has further reinforced awareness that healthy, carbon-rich soils function not only as a climate mitigation tool but also as a buffer against economic and geopolitical shocks.

Dr Thorunn Wolfram outlined how the FAO Global Soil Partnership, established in 2012 as a voluntary multi-stakeholder platform, is strengthening global soil governance and coordination. Key outcomes from its 14th Plenary Assembly included proposals for an International Policy Panel on Soils and a long-term ambition to establish a UN Decade on Soil Health (2031–2040). She pointed to the RECSOIL initiative as a leading example of science being translated into implementation. In Costa Rica, RECSOIL tools have been embedded into the national Payment for Ecosystem Services (PES) programme, with direct payments for sustainable soil management scheduled to begin in July. This represents a significant shift from soil conservation as voluntary practice to soil stewardship as a financially incentivised national policy mechanism. At the heart of this transformation, she emphasised, is a conceptual shift: from viewing soil as a production input to recognising it as a living ecosystem that underpins multiple planetary functions.

Dr Leigh Winowiecki concluded the session by illustrating how soil data is increasingly informing real-world decisions. She highlighted the adoption of soil organic carbon as a reporting indicator within the African Union’s CAADP Biennial Review, and a NORAD-supported initiative to integrate soil data directly into national planning and decision-making systems, rather than leaving it confined to research outputs or static maps. She also emphasised the growing role of youth engagement in shaping the future of soil stewardship, referencing the expansion of Youth for Soil chapters and the launch of the Youth for Soil Manifesto on World Soil Day in Belém. Young people, she stressed, are not only future stakeholders in soil systems they are already active agents of change driving awareness, advocacy, and innovation in soil health globally.

Key takeaways

• Soils are a critical, scalable climate solution.
• Soils are both part of the climate problem and a major part of the solution.
• Soil carbon is powerful, but not a standalone solution.
• Measurement is the foundation of credibility and scale.
• Proven practices already exist and are ready to scale.
• Simplicity, incentives, and local relevance drive adoption among smallholders.
• Soil health and fertiliser efficiency must be integrated, not separated.
• Coalitions and partnerships are essential for system-wide transformation.

 

Looking ahead

The session closed with several announcements from the British Society of Soil Science (BSSS), highlighting upcoming opportunities for engagement across the soil science community.

• The BSSS Annual Conference will take place in Aberdeen in 2-3 December 2026, with oral abstract submissions now open, inviting contributions from across research, policy, and practice.
• Looking further ahead, BSSS is also delighted to confirm that it will be hosting the EuroSoil Conference in Edinburgh in 4-7^th September 2028, bringing one of Europe’s largest soil science gatherings to the UK and providing a major platform for international collaboration and knowledge exchange.