Forests regulate climate through exchanges of energy and materials with the atmosphere. The idea that forests affect climate is not new. A vigorous debate about deforestation, reforestation, and climate change began during European settlement of the Americas, spreading to all regions of the world before collapsing in the early 1900s. The story of forests and climate change is told as being scientifically wrong and advanced for political, economic, or cultural reasons, but it has not been told from a modern scientific perspective. In fact, it represents the foundation for the interdisciplinary study of Earth as a system. Many of the questions posed in today’s study of climate change and climate solutions have their origins in the forest-climate question. The multicentury controversy over forests and climate change is a narrative in which purposeful modification of climate is longstanding, but by felling or planting trees. Earth system science is a centuries old idea, conceived in the long-held belief that forests influence climate and doomed to fail by the disciplinary specialization of the sciences. Narrow-mindedness prevented a vision of the world as an interconnected system.

WWS technologies eliminate energy-related emissions. However, some emissions that affect human health and climate are not from energy sources but must still be reduced or eliminated in order to help solve the air pollution and climate problems we face. Such nonenergy emissions include gases and particles from open biomass burning; methane from agriculture and landfill waste; halogens from leaks and their reckless disposal; and nitrous oxide from fertilizers, industry, and wastewater treatment. These sources of emissions and methods of controlling them are discussed in this chapter.

Climate services (CS) and agricultural advisory services (AAS) have the potential to play synergistic roles in helping farmers manage climate-related risk, providing they are integrated. For information and communication technology (ICT)-enabled, climate-informed AAS to contribute towards transformation, the focus must shift from scaling access to scaling impact. With expanding rural ICT capacity and mobile phone penetration, digital innovation brings significant opportunities to improve access to services. Achieving impact requires the following actions: building farmers’ capacity and voice; employing a diverse delivery strategy for CS that exploits digital innovation; bundling CS, agri-advisories, and other services; investing in institutional capacity; and embedding services in a sustainable and enabling environment in terms of policy, governance, and resourcing. Recent experiences in several countries demonstrate how well targeted investments can alleviate constraints and enhance the impact of climate-informed AAS.

Our food systems have performed well in the past, but they are failing us in the face of climate change and other challenges. There is a broad consensus that transformation of food systems is required to make them sustainable and equitable for all. Transformation occurs via agents of change: individual behaviour, policies and institutions, research and innovation, and partnerships and alliances. Outcome-oriented agricultural research for development can help bring about directed transformation that maximises benefits and minimises trade-offs.

Transforming our food systems will require changing our innovation systems, in which organisations on agricultural research and innovation can play a crucial role. Key success factors for change can be organised into three dimensions: designing and managing transformative innovations, culture and structures of innovation organisations, and their engagement with the wider innovation ecosystem. Failures are crucial elements of innovation processes. Rapidly testing, sharing, building on, and learning from successful, and failed, innovations are key. This connects to the paradigm ‘Open Innovation 2.0’, which is widely applied in the private sector but not yet applied and evaluated for research and innovation organisations in the public sector or tertiary education. Four key principles emerge, namely big-picture action-oriented thinking, entrepreneurial organisational culture, close attention to partnerships and contexts, and diverse investment portfolios, with different levels of risk. These also imply—and require—the upstream transformation of funding and incentive systems.

Transforming global food systems to meet sustainability and justice outcomes under climate change requires engaging with complex multi-level governance while appreciating specific local contexts. As such, climate change and food security are ‘messy’ policy issues; policies need to be effectively shaped and fit for purpose across different scales, geographic areas, and sectors. Policy implementation necessitates coordination across multiple perspectives towards a common goal, and an anticipatory governance approach can enable this. Working against the status quo is not easy but can be achieved through truly engaged and inclusive stakeholder processes. Redistribution of power entails employing a gendered, socially inclusive lens in the development of food system transformation policies. Establishing an enabling policy environment for transforming food systems requires diverse approaches and multiple perspectives. The appropriate facilitation and coordination of multi-stakeholder engagements is key to clear communication between participants and to support learning.

Organisational empowerment is a critical pathway to support the sustainable transformation of food systems, mediated through different types of organisations. Collective action can be an effective strategy to include marginalised groups who may otherwise be excluded from agricultural development, extension, financing, or other aspects of climate-resilient food security. Key empowerment actions by farmer and producer organisations include building capacity, supporting greater access to inputs and information, facilitating the formation of agricultural enterprises, connecting to policy and markets, and encouraging youth membership and leadership. A focus on livelihoods, production, and poverty reduction can be a basis for increased agency and influence in decision-making. Women’s collective action is a platform to access information, technology, and a share of finances, which can lead to agency and leadership in local decision-making. For youth organisations, it is important to mobilise finance, provide support to post-production activities, support rural youth networks and recognise the role of young women in food systems.

Understanding the climate-security nexus requires framing risks and resilience, which often reflects a negative cycle of fragility, climate vulnerability, and human insecurity. Climate actions, however, can enhance a society’s climate resilience and generate pathways toward improved peace and security. These actions include constructing a tighter continuum from humanitarian assistance to development processes, providing early warnings for food security planning, building local capacity to translate early warnings and climate-informed advisories, climate-smart mapping and adaptation planning, designing adaptive safety net programs, and enabling risk finance to facilitate early action. Additional changes and interventions, such as improving multi-level governance, utilizing climate security evidence, creating conflict-sensitive policy, and linking innovation with resilience, can also help break the cycle between climate and conflict, align climate actions to peace objectives, and thereby contribute to a climate-resilient peace.

Development finance actors and the private sector will need to work cohesively to reduce the funding gap, reorient current financing, and increase capital resources for food-system transformation. Utilising innovative financing instruments and mechanisms, such as blended finance structures, to create attractive investment opportunities can catalyse food-system transformation through both public and private sector capital. Building the capacity of financial intermediaries to accurately assess risk and deploy appropriate risk-mitigation mechanisms can improve risk perception and lower the transaction cost for deploying capital. Robust, science-based metrics, cost-effective data collection, and monitoring systems are critical to mobilising capital and safeguarding sustainable finance against ‘greenwashing’, engaging in behaviour or activities that make people believe a company is doing more to protect the environment than it really is.

Rerouting farming and rural livelihoods to new trajectories can help tackle increasing youth unemployment and failing food systems. While agriculture must be made more attractive by promoting ‘stepping up’, alternative livelihoods based on allied economic sectors must be considered for ‘stepping out’. Actions can be taken to invest in secondary and tertiary rural industries and improve access to adequate financial services and skills, to enhance automation and tools for more efficient development of agricultural activities, to invest in training and re-skilling of the workforce for rural dwellers to engage in agribusinesses and entrepreneurship, and to create safety-net programmes to prevent ‘falling down’ and ‘dropping out’. These actions must be inclusive of both women left behind in farming, and next-generation rural youths who are increasingly disenfranchised and prone to migration.

Relative to agricultural systems, high-carbon ecosystems – such as forests, peatlands, and mangroves – store large amounts of carbon in relatively small areas. Agricultural expansion often comes at the expense of high-carbon ecosystems, contributing to climate change. The food system is connected to these challenges. Ensuring no further agricultural expansion occurs in high-carbon ecosystems is a substantial climate change mitigation opportunity. The estimated costs of avoiding deforestation range from US$1.1 to US$395 billion per year, depending on growth scenarios and carbon prices; this is a bargain compared to the leverage these systems have on climate change and its social costs. Individuals, indigenous people, policies, institutions, and investments are all agents of change and will have to work together to avoid further land conversion.

Transformation is required in complex food systems to bring about global food security for a well-nourished world population while meeting climate-related challenges. The key is to identify the best levers to achieve change. To this end, food-system transformation has four major interlocking elements: (1) rerouting systems and livelihoods into new trajectories; (2) addressing climate impacts, thereby reducing risks; (3) tackling new environmental issues, for example by reimagining diets and value chains, to lessen emissions; and (4) realigning the ’enablers of change’, such as policies, regulation, finance, and innovation. Eleven specific, concrete actions are proposed to attain these four objectives, with explanations of the goal of each action, the mechanisms to accomplish it, targeted geographic areas, and key stakeholders. Achieving food-system transformation will require annual investments of US$850 billion from now until 2050, with private-sector finance helping to fill current gaps.

Food loss and waste (FLW) are important contributors to food insecurity, with a considerable environmental impact by inducing extra crop production and post-harvest greenhouse gas (GHG) emissions. FLW and the associated climate impacts vary greatly among different adopted technology and value-chain configurations, and solutions should be found for specific situations. FLW can be approached from a chain perspective; in many cases, reducing FLW at a certain chain stage is best achieved by interventions elsewhere along the chain. The Agro-Chain Greenhouse Gas Emissions (ACE) calculator supports the identification of FLW and GHG emission hotspots along a chain, as well as estimating the net effects of interventions. FLW-reducing interventions mostly contribute to climate mitigations, as demonstrated for rice and various fruits and vegetables; however, some high-tech interventions may induce higher extra GHG emissions than can be mitigated by FLW reduction. In high-income countries, where most food is wasted by households, manufacturers, the hospitality and food industry, and retailers, mechanisms could be set in place to achieve the target of reducing food waste by 50 percent by 2030.

The agricultural research for development (AR4D) domain is becoming increasingly complex, and theory of change (ToC) approaches can provide critical guidance through the maze of transformation concerning engagement, partnership, and research. Most of the major benefits that accrue through the use of ToCs relate to internal learning within project teams. Finding the balance between applying a ToC that is both useful and time- and resource-smart is challenging and may need iteration to get right. Quantitative impact assessment methods must be blended with qualitative methods in ToC-based AR4D, so that evaluation becomes about both the process and numbers, while new methods require developing for blended evaluation. The evidence base concerning the efficiency, efficacy, and failings of ToC-based AR4D urgently requires further development and synthesis, and the lessons must be applied broadly.