1st International Conference of Soil and Agriculture:
TOWARDS SOIL SUSTAINABILITY
11–13 June 2024 • Lublin–Nałęczów, Poland

https://doi.org/10.24326/ICSA1.0.03
Published online: 4 October 2024

Unlocking agricultural soils’ potential for climate change mitigation: Are carbon certificates a suitable tool?
Carsten Paul¹*, Bartosz Bartkowski², Cenk Dönmez^1,3, Axel Don⁴, Stefanie Mayer⁵,
Markus Steffens⁶, Sebastian Weigl¹, Martin Wiesmeier^5,7, André Wolf⁸,
Katharina Helming^1,9

¹ Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374, Müncheberg, Germany
² UFZ – Helmholtz Centre for Environmental Research, Department of Economics, Permoserstraße 15, 04318, Leipzig, Germany
³ Cukurova University, Landscape Architecture Department, Remote Sensing and GIS Lab, 01330 Adana, Turkey
⁴ Thünen Institute of Climate Smart Agriculture, Bundesallee 65, 38116, Braunschweig, Germany
⁵ Chair of Soil Sciences, TUM School of Life Sciences, Technical University of Munich, Emil-Ramann-Straße 2, 85354, Freising, Germany
⁶ Department of Soil Sciences, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, 5070, Frick, Switzerland
⁷ Bavarian State Research Center for Agriculture, Institute for Organic Farming, Soil and Resource Management, Vottinger Straße 38, 85354, Freising, Germany
⁸ UFZ – Helmholtz Centre for Environmental Research, Department of Environmental and Planning Law, Permoserstraße 15, 04318, Leipzig, Germany
⁹ Faculty of Landscape Management and Nature Conservation, University of Sustainable Development (HNEE), Schicklerstr. 5, 16225, Eberswalde, Germany
* Corresponding author:

Abstract
In agricultural soils, carbon farming measures increase the soil organic carbon (SOC) stock, resulting in the removal of CO₂ from the atmosphere. A long-term removal of carbon contributes to climate change mitigation and the achievement of climate neutrality targets. At the local scale, raising SOC levels increases water holding capacity, infiltration rate, biological activity and nutrient turnover, thereby helping to adapt to climate change impacts and to maintain soil fertility. However, carbon farming measures also come with direct and indirect costs to farmers which have so far hindered wide-spread implementation. Private governance tools such as soil-based carbon certificates sold as voluntary emission-offsets could help to overcome this by providing farmers with financial incentives. However, in spite of a high interest from industry, policy makers and farmers, the suitability of such certificates as a tool for climate change mitigation is under debate. To address existing knowledge gaps, we assessed the suitability of soil-based carbon certificates from the perspectives of soil science, agriculture, and governance. We focussed on certification for carbon stock increases in mineral soils in Europe, using commercial certification schemes available in Germany as examples. Our analysis reveals severe shortcomings in the analysed schemes. Problems mainly pertain to governance, though the permanence of carbon removals was found to be challenging under all three perspectives. As carbon storage cannot be guaranteed over climate-relevant timespans and as long-time monitoring is typically lacking, re-emission of unspecified amounts of CO₂ after the end of the contracting period are highly likely. Furthermore, additionality is not ensured, and safeguards against leakage effects are insufficient. We conclude that current soil-based carbon certificates on mineral soils are unsuitable as a tool for climate change mitigation and that they are not delivering the emission-offset they promise. Funds for climate change mitigation should therefore be used more effectively elsewhere. Finally, we compare the analysed certification schemes on mineral soils with certification schemes based on the rewetting of organic soils, and we discuss in how far the planned European CDR framework may be able to overcome the shortcomings identified in our study.

Keywords: carbon sequestration, permanence, offset, CDR, agriculture, private governance

How to cite
Paul C., Bartkowski B., Dönmez C., Don A., Mayer S., Steffens M., Weigl S., Wiesmeier M., Wolf A., Helming K., 2024. Unlocking agricultural soils’ potential for climate change mitigation: Are carbon certificates a suitable tool?. 1st International Conference of Soil and Agriculture: Towards Soil Sustainability. https://doi.org/10.24326/ICSA1.0.03