Importance of Soils of Agroecosystems for Climate Change Policy

Abstract

Until now, international climate change policy has neglected the potential of agroecosystems to contribute to climate change mitigation by reduction in net greenhouse gas (GHG) emissions, and by enhancing soil inorganic carbon (SIC) and soil organic carbon (SOC) sequestration. Proven agricultural practices for creating a positive soil C balance such as those under the umbrella of climate-smart agriculture (CSA) are readily available. In the future, the importance of soil C stocks for climate change mitigation will be addressed by the target of Land Degradation Neutrality (LDN) of United Nations Convention to Combat Desertification (UNCCD), and land- and soil-related targets for achieving United Nations Sustainable Development Goals (SDGs). Further, many nationally determined contributions (NDCs) submitted to United Nations Framework Convention on Climate Change (UNFCCC) after the 2015 Paris Agreement include references to soil enhancement and to the necessity of better soil management practices. Similarly, an ambitious goal to increase global soil C stocks of managed agricultural land by 0.4% per year in the topsoil was set by the ‘4 Per 1000 Initiative: Soils for Food Security and Climate’ (4p1000). Based on this, spatially diversified strategies need to be developed to sequester SOC in agroecosystems by addressing limitations imposed by nutrient (i.e., nitrogen and phosphorus) availability, and due consideration of economic and social aspects. Thus, meaningful actions that help to restore and protect soils of agroecosystems including their SOC stocks have been initiated recently. It is hoped that soils of agroecosystems will increasingly be managed to address climate climate change while at the same time contributing to food security under increasing pressure from population growth and dietary changes. This chapter begins with an overview over some practices to enhance soil C stocks in agroecosystems for climate and food security. This is followed by a description of previously proposed climate change mitigation policies and their reference to agroecosystems soil C stocks. Then, a brief overview over CSA, carbon farming, and the soil security framework is given. This chapter concludes with a section on payments for ecosystem services (ESs).