What soils can and cannot deliver when it comes to climate mitigation

Background/Question/Methods

From media coverage to corporate climate commitments, addressing climate change is becoming an increasingly urgent activity. Soils are touted as a win-win natural climate solution that can draw down carbon from the atmosphere and support agricultural producers. More than 38 percent of the global terrestrial surface is under some form of agricultural management. Food and agricultural systems offer a range of opportunities for carbon sequestration and climate mitigation, with the potential to be widely adopted across diverse regions and landscapes. As governments, companies, and individuals look for ways to reduce their carbon emissions and meet their climate goals, a number of voluntary markets and soil C crediting platforms and protocols have emerged to meet the growing demand for soil C credits - some rely on physical measurements, some on modeling, some on monitoring practices or changes in land cover to quantify carbon sequestration and issue credits.

Results/Conclusions

Reviews of publicly available soil C protocols suggest that variation among protocols in key factors including soil organic carbon (SOC) quantification, permanence, and additionality result in very different carbon credit generation,. Moreover, variation in the way protocols approach and estimate soil C suggest that the resulting credits issued by different protocols will not be equivalent. This is especially problematic in the context of climate change mitigation if entities that purchase soil C credits are using them to compensate for emissions elsewhere. As soil C solutions continue to be developed, it is critical to apply the latest scientific thinking, rigor, and transparency to ensure solutions are real and entities that use soil C credits are accountable from a climate perspective.