Climate change poses a major challenge to agriculture. Rising temperatures will change crop growing seasons. And changing rainfall patterns will affect yield potentials. Underinvestment over the past 20 years has left the agricultural sector in many developing countries ill-prepared for the changes ahead. Policymakers and researchers alike acknowledge the need for adaptation within agriculture. But what action should be taken? And, more importantly, how much will it cost? Five case studies — of specific agricultural systems in Bangladesh, Malawi, Nepal, Rwanda and Tanzania — provide fresh insights into the options available and likely costs, which are at least US$20,000 for an integrated cropping system in a village, and may well be more than US$100 million for a whole sector such as
livestock in a country.