Climate change adaptation, mitigation and food security may be addressed at the same time by enhancing soil organic carbon (SOC) sequestration through environmentally sound land management practices. This is promoted by the "4 per 1000" Initiative, a multi-stakeholder platform aiming at increasing SOC storage through sustainable practices. The scientific and technical committee of the Initiative is working to identify indicators, research priorities and region-specific practices needed for their implementation. The Initiative received its name due to the global importance of soils for climate change, which can be illustrated by a thought experiment showing that an annual growth rate of only 0.4% of the standing global SOC stocks would have the potential to counterbalance the current increase in atmospheric CO₂. However, there are numerous barriers to the rise in SOC stocks and while SOC sequestration can contribute to partly offsetting greenhouse gas emissions, its main benefits are related to increased soil quality and climate change adaptation. The Initiative provides a collaborative platform for policy makers, practitioners, scientists and stakeholders to engage in finding solutions. Criticism of the Initiative has been related to the poor definition of its numerical target, which was not understood as an aspirational goal. The objective of this paper is to present the aims of the initiative, to discuss critical issues and to present challenges for its implementation. We identify barriers, risks and trade-offs and advocate for collaboration between multiple parties in order to stimulate innovation and to initiate the transition of agricultural systems toward sustainability.

Soils have recently received attention in the policy area due to their various connections to climate change, human health and their key role in sustaining human societies in general. In this context, agricultural production and healthy nutritious food are linked to soil health and the diversity of their (micro-)biome, which depend on organic carbon materials as an energy and nutrient source. In this paper, we review the evidence showing that carbon-rich soils improve the resilience of human societies to pandemics and other crises. We indicate pathways for how the loss of soil carbon due to farming could be reversed by transformations within our food systems. Moreover, we argue that soil carbon has a strong role to play in enhancing environmental and human health in addition to mitigating and adapting to climate change. This multifaceted role requires a transdisciplinary dialogue and multi-stakeholder collaboration.