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.

There have been several calls for transformation in food systems to address the challenges of climate change, hunger, continuing population pressure, and to meet the Sustainable Development Goals (SDGs). Although complicated, working across scales and actors is critical for food-system transformation, alongside understanding the entry points. As agricultural research for development (AR4D) is ultimately about farming practices and farmer livelihoods, a focus on the local scale is essential, as in most cases, farms and districts are where the most action is required. Through effective cross-scale work, lessons from local levels can shape the thinking of regional and national governments, as well as the private sector. Involving multiple and ideally nested scales, designing sets of solutions, and developing actionable, fundable, and implementable solutions is likely to provide rich food-system outcomes. Partners need to provide the tools, signals, and resources so that local people, communities, and policy planners are empowered to drive transformation.