Carbon for soils, not soils for carbon

Résumé

Soil organic carbon (SOC) sequestration is increasingly promoted as a ‘win-win’ solution to address both climate change and food security, arguably two of the most pressing and complex contemporary global threats. Current enthusiasm is very high in the science community as well as in the public media and increasingly in policy initiatives. Our objective is to bring nuance in the discussion and to reflect on the true potential of SOC sequestration in science and policy. To do so, we first summarise the findings of our recently published paper (Glob Change Biol. 2023;29:2384–2398). We re-emphasise that only specific management options in specific conditions hold the promise of SOC sequestration as a win-win, and that, even where and when a win-win outcome is possible, conflicts will arise when setting out to maximise both food production and SOC sequestration. We argue that the existing knowledge base does not justify the current trend to set global agendas focusing first and foremost on SOC sequestration and contend that the rapid development of largely unregulated voluntary carbon markets, wherein farmers get paid per ton of sequestered CO2, is unlikely to lead to fair and effective incentives for a transition to more sustainable farming systems. Finally, we advocate for soil carbon research and policy to fall in line behind the wealth of knowledge showing the importance of local context, of developing locally suited adaptative methods focusing on a wide set of environmental outcomes, and calling attention to social acceptability and economic viability.