The endless expansion of carbon offsetting: sequestration by agricultural soils in historical perspective.

This article examines the historical development and political legitimization of soil-based carbon sequestration (SAS) as a climate change mitigation strategy, focusing on its role in carbon offsetting within evolving climate policies centered on carbon neutrality (net zero emissions). It traces how soil sciences from the 1980s reframed soils as mechanical carbon sinks and how agricultural economics translated this potential into economically competitive offsetting opportunities, despite persistent scientific concerns about the non-permanence, reversibility, and measurement challenges of soil carbon storage. The institutionalization of SAS in international carbon accounting systems and carbon markets has relied on simplifying complex biogeochemical processes into normative equivalences between soil carbon sequestration and fossil CO2 emissions reductions, raising questions about environmental integrity and the effectiveness of offsetting. The article highlights ongoing debates about the appropriateness of treating soil carbon as equivalent to fossil carbon and discusses contrasting policy approaches, including incentive-based payments versus regulatory measures, reflecting tensions between promoting sustainable agriculture and commodifying soil carbon for market trading.