Burying the carbon to dig up the future: reviewing the role of Geography in valuing soil carbon ecosystem

Soil carbon sequestration presents a pathway towards climate change mitigation and adaptation while also fostering sustainable socio-economic development. The emergence of soil carbon markets, which monetize carbon capture and land management practices, has given new impetus to this area of study. However, the intersection of environmental, social, and economic systems inherent to soil carbon markets introduces significant complexities. To understand the research landscape and the prevailing themes within the field, we conducted a systematic literature review, sourcing articles from the Web of Science and SCOPUS databases that focused on soil carbon markets, published between January 2017 and august 2023. Our analysis revealed three primary research themes emerged: 1) Soil Ecosystem Services (61%), closely associated with the agricultural and environmental sciences; 2) Environmental Economics (21%) show the growing focus on economic valuation of ecosystem services since the Paris Agreement; and 3) Exploratory Analyses (18%) highlight recent efforts in dealing with the complex network of environmental, social, economic, political and cultural factors. However, these areas of research are often treated separately, reflecting a broader disconnect between natural and social sciences: Geography, uniquely positioned at the intersection of natural and social sciences, could bridge this divide. Through a geographical lens, one can better comprehend drivers behind land management and land-use changes and how they relate to environmental indicators and soil carbon markets. In the social sciences, cultural aspects that shape soil management practices, farmers' relationships with land and markets, and their engagement with soil carbon markets could be examined to predict actions towards improving environmental performance indicators. These settings are highly local, influenced by factors like land tenure rights, landscape ecology, political settings, and power dynamics. Geography's role extends beyond merely understanding these local factors. It also involves studying 'space' and 'place', concepts that are crucial in the context of soil carbon markets. Within the framework of complexity theory and spatial agent-based modelling for socio-ecological systems, Geography can provide valuable insights into how different entities within soil carbon markets interact and influence each other. In the context of climate change, soil ecosystem services, and by extension soil carbon markets, can influence social and economic vulnerabilities. An integrated study of land use, management practices, and their impact on soil ecosystem services, using both quantitative and qualitative approaches, can provide insights into social behaviour and ecosystem responses over time.