Smallholder farmers are key contributors to global food security and nutrition. The 500 million smallholder farms in the developing world provide an estimated 80 percent of the food produced in Asia and Africa south of the Sahara.1 Yet smallholders are a vulnerable and often neglected group, who account for most of the world’s poor and hungry. Globally, the poor and hungry live predominantly in rural areas, where agriculture is their main source of livelihood.2 Smallholders face a mix of interrelated risks and challenges that threaten their livelihoods, food security, and nutrition— among these, climate change looms large. Increasing the resilience and viability of smallholder farming could both reduce rural poverty and food insecurity, and contribute broadly to the Sustainable Development Goals (SDGs).