Vulnerability to global
Diana M. Liverman
The impacts of global change on environment and society are determined as much, if not more, by the characteristics of the ecosystems and people affected as by the magnitude of the change itself. Droughts of equal physical severity may have much less severe impacts on large, commercial, irrigated farms that can rely on insurance, good soils, and subsidized prices than on smaller, rain-fed, subsistence farms that lack institutional support. Irrigation, crop diversity, and flexible land-use and management strategies may buffer agricultural systems against climate variability. On the other hand, the systems may be more sensitive to change if economics, land tenure, and resource availability restrict options for land use, irrigation, and crop choice. Deforestation will have more severe effects in regions where slopes are steep, soils are fragile, or species are already being overhunted. Certain species, ecosystems, and cultures are dispro portion ately affected by desertification. Future generations, as well as the poor, sick, and powerless, are particularly sensitive to the widespread build-up of toxic substances in the environment.
The same environmental change will have different impacts in different places because some people and places are more vulnerable than others to environmental change. In this and subsequent chapters we argue (and illustrate) that understanding vulnerability is an important component of the risk assessment of global environmental change.
The definition of the term “vulnerable” originates in the verb “to wound,” and the term has been used in a variety of ways to characterize