Climate change and hunger: Estimating costs of adaptation in the agrifood system

Book excerpt: This report assesses the cost of adaptation to climate change across a range of future climate scenarios and investment options. We focus on offsetting climate change impacts on hunger through investment in agricultural research, water management, and rural infrastructure in developing countries. We link climate, crop, water, and economic models to (1) analyze scenarios of future change in the agriculture sector to 2050 and (2) assess trade-offs for these investments across key Sustainable Development Goals (SDGs) for poverty, hunger, and water. Our reference projections show that climate change slows progress toward eliminating hunger, with an additional 78 million people facing chronic hunger in 2050 relative to a no-climate-change future, over half of them in Africa south of the Sahara. Increased investments can offset these impacts. Achieving this would require that annual investment in international agricultural research increase from US$1.62 billion to US$2.77 billion per year between 2015 and 2050. Additional water and infrastructure investments are estimated to be more expensive than agricultural R&D at about US$12.7 billion and US$10.8 billion per year, respectively, but these address key gaps to support transformation toward food system resiliency. Findings on ranges of costs and trade-offs and complementarities across SDGs will help policymakers make better-informed choices between alternative investment strategies.