Book excerpt: Seasonality is a severe constraint to sustainable rural livelihoods and a driver of poverty and hunger, particularly in the tropics. Many poor people in developing countries are ill equipped to cope with seasonal variations which can lead to drought or flood and consequences for agriculture, employment, food supply and the spread of disease. The subject has assumed increasing importance as climate change and other forms of development disrupt established seasonal patterns and variations. This book is the first systematic study of seasonality for over twenty years, and it aims to revive academic interest and policy awareness of this crucial but neglected issue. Thematic chapters explore recent shifts with profound implications for seasonality, including climate change, HIV/AIDS, and social protection. Case study chapters explore seasonal dimensions of livelihoods in Africa (Ethiopia, Kenya, Malawi), Asia (Bangladesh, China, India), and Latin America (Peru). Others assess policy responses to adverse seasonality, for example through irrigation, migration and seasonally-sensitive education. The book also includes innovative tools for monitoring seasonality, which should enable more appropriate responses.