The Paris Climate Agreement commits signatories to pursue efforts to keep global temperatures well below 2 degrees C above pre-industrial temperatures. Further, there is an aspirational target to limit warming to less than 1.5 degrees C above pre-industrial temperatures. Integrated Assessment Models show that it is now extremely unlikely that these targets can be met through greenhouse gas emission reduction alone, and that greenhouse gases will need to be removed from the atmosphere. Methods to remove greenhouse gases from the atmosphere are known as negative emission technologies (NETs) or carbon dioxide removal methods. Land based NETs include afforestation and bioenergy with carbon capture and storage, and in the soil, include soil carbon sequestration and biochar additions to the land.

Soils are indeed increasingly recognized as part of the solution in climate change mitigation strategies. Moreover, halting land degradation and increasing the levels of soil organic carbon can help increasing food security and adapting ecosystems to changing environments. These three goals of climate change mitigation, adaptation and food security are linked in the ‘4 per 1000’ Initiative which was launched at COP21 in 2015 and which is backed up by a dedicated international research program. Moreover, soils are a renewable and provisional resource, they act as reservoirs for carbon sequestration and carbon-based energy; they also provide the ecosystems with templates for physical, hydrologic, and biogeochemical processes. As resources for such diverse uses, we need frameworks for data, monitoring, and conceptual underpinnings so that the complexity of soil can be tracked and understood for planning and implementation.

This session aims at bringing together scientists across many disciplines (soil sciences, carbon cycle, agronomy, forestry, geography, economics, political sciences and sociology) around the topics of (i) soil carbon sequestration studied from different perspectives at different scales and in different pedo-climatic conditions and (ii) soils based NETs,, their potential and limitations as well as the synergies and trade-offs with other ecosystem services and sustainable development goals. We welcome contributions that highlight new technologies, frameworks, and big-data approaches to enable cross-cutting information, protection from erosion and degradation, and construction of incentives for implementing good soil stewardship.

The following aspects can be covered in the contributions: estimation of the potential for soil carbon sequestration, design and study of agronomic and forestry practices that store carbon, policies and mechanisms that incentivize change, monitoring, reporting and verification of soil carbon sequestration.