Trends and challenges in carbon farming

To be impactful at a scale required to face the current climate crises, carbon farming needs to financially support the adoption of new practices by farmers from one side, and maintain a high level of environmental integrity from the other. To cover the financial aspects, the vision of the European Commission (following pilot experiences in Australia and in the State of California) is to enable a system that considers carbon as an extra product that land managers can sell. On the demand side, there is an interest in the generated carbon credits because they can be purchased by actors (from individuals to corporations) to reduce their own climate footprint. This basic mechanism of compensating one's footprint through a beneficial action taken elsewhere is called carbon offsetting, and has been criticised by some because it can be seen as a permit to pollute. However, every serious professional in the sector would agree that climate neutrality must be built on reducing GHG emissions of every organisation, and offsetting is in fact only useful as a complementary strategy to compensate for emissions very difficult to abate.

Carbon offsetting must be seen as the last resource for organisations to reduce their climate footprint.

What is considered by many a better option for carbon farming is to generate financial incentives by carbon insetting. This mechanism refers to interventions along a company's value chain that are designed to generate removals or emissions reductions. For example, a large food retailer could pay orange producers for uptaking a practice increasing long-term carbon storage in the soil. As a consequence, the retailer could take credits for the removed carbon linked to its orange juice value chain. Whether offsets or insets, everyone agrees that the focus must be on the quality of the removed/avoided carbon unit. This is, carbon actions should be permanent and additional, avoiding leakage and ideally having a positive impact on communities and ecosystems. And this is where it gets tricky.

In fact, carbon linked to land uses is generally considered to be relatively volatile, in the sense that it is very easy to reverse the direction of the flux, from removed to emitted. For example, the carbon removed by planting trees would return straight back to the atmosphere in case of a fire. Furthermore, agricultural carbon farming most often refers to the goal of increasing soil organic carbon, and soils pose the extra challenge of being highly heterogeneous, hampering an easy monitoring of carbon stocks. This is why a current research and innovation focus of many international agencies is in financing the development of rigorous monitoring, reporting and verification systems (MRVs) for carbon fluxes, enabling cost-effective quantification of the climate impact of specific actions. Aligned with this need, another goal of the Farms4Climate project is indeed the co-creation of semi-automatic MRV systems that can help land managers to support their quality claims. In this respect, soil organic carbon has been historically monitored through sampling and laboratory analysis, but this is too expensive to be implemented at a large scale. At the same time, new proximal and remote sensing tools are emerging, but are often considered of lower monitoring value, as they estimate carbon stocks by measuring linked variables (in other words, they provide indirect measurements). Therefore, the general consensus is to develop MRV methodologies that integrate different approaches, including taking actual samples to run models on carbon dynamics, and trying to correlate sampled data with the increased monitoring capacity of earth observation satellites or other proximal multispectral equipment. However, what is clear is that a single silver-bullet approach to soil carbon monitoring is unlikely to arise, and methods must be locally adapted and validated to support robust carbon schemes. A rule of thumb for the selection of monitoring approaches for soil carbon farming is presented in the section on how to launch a carbon project.

Carbon pricing is considered by many the ultimate tool to keep resource usage within planetary boundaries