The unprecedented and long-term nature of environmental change in the 21st century has given rise to a new discourse on vulnerability to such change, where vulnerability implies harm from which it is difficult to recover. Understanding why people, ecosystems or food systems are vulnerable to shocks, stresses or long-term change such as the impacts of climate change is the key to developing adaptation options in the face of new threats, or to taking advantage of new opportunities from change. Although adaptation has long been the human reaction to change, the pace and scale of global environmental change (GEC) require proactive and planned adaptation, particularly to avoid further negative feedbacks to either ecosystems or food security. As shown in Part I of this book, food system activities have contributed to many of the environmental changes that now threaten food security. At the same time, food insecurity arises from deep-rooted structural problems such as chronic poverty, missing markets and social factors restricting access. Adaptation strategies to improve food security or ameliorate loss of ecosystem services are not guaranteed to work. Proponents of the ‘sustainable adaptation’ concept (Eriksen and O’Brien, 2007) argue that adaptation to climate change must also address poverty and development goals. Similarly, proponents of fostering or managing resilience in ecological systems are concerned with systems’ abilities to cope with external change in a way that does not undermine the systems themselves (Cumming et al, 2006; Folke, 2006). Part II of this book will explore these approaches in relation to food systems and food security.