Many aspects of global environmental change (GEC) contribute to the vulnerability of food systems. These may stem from factors embedded in society, in the natural environment, or from social–environmental interactions and feedbacks. Environmental stresses and changes can also alter the ‘internal’nature of food systems to undermine their capacity to respond or adapt, which can make them vulnerable to changes they could formerly cope with, as illustrated in Chapter 6. Such feedbacks give rise to additional causes of vulnerability. Stresses and changes do not function in isolation from one another, but co-occur and interact in numerous ways. Climate change and economic globalization, for example, are understood to synergistically drive a particular kind of vulnerability in regions or among systems ‘doubly exposed’to both; this can lead to compound negative outcomes, such as the simultaneous loss of agricultural productivity and social services (O’Brien and Leichenko, 2000; Leichenko and O’Brien, 2008).