Vulnerability to climate change is the extent to which climate change may damage or harm a system and is a function of a system’s exposure, sensitivity and adaptive capacity (McCarthy et al, 2001). Applying this conception of vulnerability, an index of vulnerability of peasant households is constructed and used to rank the 30 states of the Nigerian Federation from least to most vulnerable. The analysis produces a depiction of the spatial distribution of vulnerability that is a synthesis of several investigations of climate variability, climate change and food security in Nigeria, the details of which are reported in Adejuwon 2005a, 2006a and 2006b.