Book excerpt: Two of the greatest current challenges are climate change (and variability) and food security. Feeding nine billion people by 2050 will require major efforts aimed at climate change adaptation and mitigation. One approach to agriculture has recently been captured by the widely adopted term of "Climate Smart Agriculture" (CSA). This book not only explains what this entails, but also presents practical on-the-ground studies of practices and innovations in agriculture across a broader spectrum, including agroecology and conservation agriculture, in less developed countries. It is shown that CSA is not a completely new science and a number of its recommended technologies have been used for some time by local farmers all over the world. What is relevant and new is ‘the approach’ to exploit their adaptation and mitigation potential. However, a major limitation is the lack of evidence-based knowledge that is necessary for policy makers to prepare strategies for adaptation and mitigation. This book assembles knowledge of CSA, agroecology and conservation agriculture, and perspectives from different regions of the world, to build resilient food systems. The first part analyzes the concept, opportunities and challenges, and provides a global perspective, drawing particularly on studies from Africa and Asia. The second part of the book showcases results from various studies linked to soil, water and crop management measures from an ongoing program in India as well as experiences from other regions. The third section assesses the needs for an enabling policy environment, mainstreaming gender and sime final recommendations for up-scaling and/or out-scaling innovations.