Editorial: Tuyeni H Mwampamba, Rob Bailis, Adrian Ghilardi Urbanization, food, and water consumption trends in many tropical countries show that demand for charcoal (as a source of cooking energy), meat, grain and water will rise to proportions that surpass the ability of existing ecosystems to supply these services simultaneously and at desired qualities. Consequently, drastic changes to policy and practice are needed to improve ecosystem potential and/or alter demand trends. Traditional charcoal production in sub-Saharan Africa, South East Asia and Latin America often competes or co-exists with livestock keeping and agriculture and has a tendency to occur in water-limited woodlands. The co-occurrence of charcoal and food production results in complex landscapes characterized by strong interactions between subsystems, managed by multiple sets of actors, with potentially competing objectives. These social-ecological systems provide goods and services that are essential to millions of people throughout the global south. Nevertheless, there have been very few detailed studies of such systems, particularly on the individual and combined effects of charcoal, crop, and livestock production on the hydrological system that maintains them and vice versa. As a result, these multi-use landscapes are typically managed by short-sighted, highly generalized, mono-sectorial policies that ignore important tradeoffs and undercapitalize on synergies. A system-level approach could provide important insights that improve and expand current understanding of this energy-food-water nexus. Tackling urgent and complex problems composed of multiple and interrelated factors lies at the heart of nexus thinking - an approach that “examines the inter-relatedness and interdependencies of environmental resources and their transitions and fluxes across spatial scales and between compartments” (UNU-FLORES 2015) and relies on interdisciplinary research and multi-sector policy teams. It has attracted significant interest from international organizations, the private sector and governments as a way to develop integrated equitable solutions that involve inputs from multiple stakeholders. However, this approach is notably absent in the research arena. Identifying appropriate interventions for achieving sustainable charcoal and food production and maintaining the underlying hydrological system on which they depend requires that the systems are considered simultaneously and that their biophysical, social, and political inter-relations are well understood. Taking charcoal as the nexus entry-point, this Research Topic aims to generate new understanding of charcoal production systems by incorporating agriculture and hydrology into the matrix. We were interested in empirical articles, reviews, meta-analytical articles and perspective papers that address at least two of the three nexus components and which offer provocative and insightful perspectives into the nexus as a whole. We hope that this Research Topic will 1) facilitate identification of research gaps, policy opportunities and priorities for the nexus, 2) kick-start the development of a community of researchers and practitioners working on the nexus, and 3) permit the development of a research agenda that explores the nexus globally across multiple study sites.

The book’s primary intention is to serve as a roadmap for professionals working in developing countries interested in the Nexus Water-Energy-Food-Ecosystems (WEFE) approach. The book shows a multi-disciplinary approach, showcasing the importance of the proper use of Nexus WEFE when implementing certain development programs in regions around the globe. It can be presented as a manual for an individual that either wishes to implement intervention projects following the NEXUS approach or students interested in cooperation and development. The book begins with a general explanation of the theoretical concepts and implementation processes of Nexus WEFE and continues getting into case studies, explaining the importance of proper implementation and potential drawbacks and solutions to them. This book has a particular focus on the European Union cooperation policies when implementing such an approach in developing countries.

Charcoal is widely used for cooking and heating in developing countries. The consumption of charcoal has been at high level and the demand may keep growing over the next decades, particularly in sub-Saharan Africa. Some preliminary studies indicate that among commonly used cooking fuels, unsustainably produced charcoal can be the most greenhouse gas intensive fuels and simple measures could deliver high GHG mitigation benefits. Through the Paris Agreement on climate change adopted in 2015, countries set themselves ambitious targets to curb climate change, and forest-related measures have an important role to play in climate change mitigation and adaptation. Over 70% of the countries who have submitted their (intended) nationally determined contributions (NDCs) mention forestry and land use mitigation measures. Despite the importance of woodfuel in many countries, few have explicitly included measures to reduce emissions from woodfuel production and consumption. Many of the NDCs that include forestry do not yet provide detailed information on how mitigation is to be achieved. The overall objective of the publication is to provide data and information to allow for informed decision-making on the contribution sustainable charcoal production and consumption can make to climate change mitigation. More specifically, the publication aims to answer the following questions: - What are the climate change impacts of the current practices on charcoal production and consumption worldwide and across regions? - What is the potential of sustainable charcoal production in GHG emission reductions and how such potential can be achieved? - What are the key barriers to sustainable charcoal production and what actions are required to develop a climate-smart charcoal sector?

The report creates contexts for a systemic understanding of the CGIAR Transforming agric-food system (TAFS-WCA) initiative starting with work package (WP) 3 and expanding the causality effects across the other WPs of the Initiative. The main focus of WP3 is inclusive landscape management, whereby access to and proper use of land and water resources is a prerequisite to building a healthy, productive environment for resilient agri-food systems and livelihoods. Mapping synergies with other Work Packages ensure that respective contributions are integrated and impactful. The process intends to provide policymakers, researchers, and practitioners with a strategic framework to activate solutions temporarily with a stakeholder-defined suite of scenarios.

Due to global transformational trends, such as population growth, economic development and climate change, energy, water, land and human resources are increasingly under pressure to support societal development and to maintain necessary services. Decision makers need improved tools in order to be better informed about trade-offs and synergies between different development and management choices, and to help them identify options on how to sustainably manage resources. This report proposes a way to carry out a water-energy-food nexus assessment approach in order to: a) understand the interactions between water, energy and food systems in a given context, and b) evaluate the performance of a technical or policy intervention in this given context. The ultimate goal of the nexus assessment is to inform nexus related responses in terms of strategies, policy measures, planning and institutional set-up or interventions.

Soil organic carbon (SOC), a key component of the global carbon (C) pool, plays an important role in C cycling, regulating climate, water supplies and biodiversity, and therefore in providing the ecosystem services that are essential to human well-being. Most agricultural soils in temperate regions have now lost as much as 60% of their SOC, and as much as 75% in tropical regions, due to conversion from natural ecosystems to agricultural uses and mainly due to continuous soil degradation. Sequestering C can help to offset C emissions from fossil fuel combustion and other C-emitting activities, while also enhancing soil quality and long-term agronomic productivity. However, developing effective policies for creating terrestrial C sinks is a serious challenge in tropical and subtropical soils, due to the high average annual temperatures in these regions. It can be accomplished by implementing improved land management practices that add substantial amounts of biomass to soil, cause minimal soil disturbance, conserve soil and water, improve soil structure, and enhance soil fauna activity. Continuous no-till crop production is arguably the best example. These soils need technically sound and economically feasible strategies to sustainably enhance their SOC pools. Hence, this book provides comprehensive information on SOC and its management in different land-use systems, with a focus on preserving soils and their ecosystem services. The only book of its kind, it offers a valuable asset for students, researchers, policymakers and other stakeholders involved in the sustainable development and management of natural resources at the global level.

The water–food–energy nexus is emerging as a critical issue in Asia and the Pacific. It is clear that solutions must be found to assure water security, thereby eliminating the immediate---and increasing---risk to food security, energy security, and economic growth and stability: water must be recognized as an economic as well as a social good. Governments need to be encouraged to think differently about water, take the longer-term view, and be mindful of the strategic and economic value of this limited resource. This publication is the result of a scoping study initiated by the Asian Development Bank to better understand the issues associated with the water–food–energy nexus in Asia and the Pacific. It provides high-level guidance on the choices available to address the region's water security issues.