Farmland can trap greenhouse gases inside soil

Carbon farming offers a promising method to capture greenhouse gases and mitigate climate change. The process of "capturing" CO2  by removing it from the atmosphere and storing it in the soil carbon pool enhances carbon sequestration while improving ecosystem services, supporting a circular economy, and protecting biodiversity. Key techniques include agroforestry, soil organic cover, reduced ploughing, efficient water use, and integrated fertilisation management. However, in the Mediterranean region, technical, economic, and social challenges hinder its large-scale adoption.

Carbon markets incentivise emissions reductions by assigning financial value to carbon sequestration. An article by The Conversation has summarized the three main trading systems:

Regulated Markets – The European Emissions Trading System (EU ETS) enforces legal limits on emissions for industries such as transport and aviation but currently excludes agriculture.

Voluntary Markets – Companies not legally required to cut emissions purchase carbon credits for corporate sustainability goals. These projects undergo independent certification.

Hybrid Systems – These combine elements of both regulated and voluntary markets but face criticism for potential greenwashing due to limited transparency and standardisation.

In 2021, the European Commission introduced a voluntary framework to certify carbon capture projects in agriculture, linking them to the EU’s Common Agricultural Policy (CAP) for financial incentives. However, due to the Mediterranean’s complex agricultural and climatic conditions, monitoring and verifying soil carbon levels remains difficult.

Challenges in Measuring Carbon Sequestration

The Mediterranean region’s diverse agro-climatic conditions complicate accurate carbon measurement. Extreme weather events, including droughts, heat waves, and heavy rainfall, disrupt carbon sequestration patterns. Additionally, soil composition varies—limestone, clay, and sandy soils each have different capacities for carbon retention, making monitoring inconsistent and costly.

To address these issues, research institutions like the UVic-UCC BETA Technological Centre are developing specialised methodologies for more precise carbon assessment. 

Accurately quantifying soil carbon sequestration is essential for carbon farming to function within carbon markets. Long-term projects use soil samples to estimate organic matter content and corresponding CO₂ levels. These models work best in homogeneous landscapes, like the U.S. Corn Belt, but require region-specific calibration for Mediterranean conditions.

Another method is remote rensing, where high-resolution multispectral satellite imagery captures data on soil properties, including organic matter levels, to estimate carbon uptake.

Unmanned aerial vehicles can also collect detailed vegetation and soil data to assess moisture and biomass, both of which are linked to carbon sequestration.

CO₂ Flux Towers are high-tech instruments measure gas concentrations in the air to track CO₂ absorption and release from the soil. The collected data is processed to determine carbon storage levels.
Carbon farming has the potential to enhance climate resilience and support environmental sustainability, but the Mediterranean’s agricultural diversity requires tailored measurement approaches. To succeed, carbon markets and CAP incentives must adapt to regional conditions, ensuring that carbon sequestration efforts are accurately quantified and fairly rewarded.

By Nazrin Sadigova