“…Thus, Sauer's challenge to mid-twentieth-century geography (Price and Lewis 1993) was itself challenged, first by approaches incorporating human behavior, decision-making, and systemic linkages (Brookfield 1962(Brookfield , 1964Stoddart 1965;Grossman 1977;Porter 1978;Butzer 1980Butzer , 1989bDenevan 1983;Zimmerer 1996), and second by historical approaches informed by social theory and postmodernism (e.g., Braun and Castree 1988;Cosgrove and Daniels 1988;Cronon 1991Cronon , 1995. 35 The Chicago risk-hazard tradition, which critiqued behavioral models based on "perfect knowledge" (Wescoat 1987), was itself appraised by critical approaches (Hewitt 1983;Watts 1983;Emel and Peet 1989), ultimately paving the way for political ecology and its hybrids (Blaikie and Brookfield 1987;Roberts and Emel 1992;Peet and Watts 1996;Rocheleau, Thomas-Slayter, and Wangari 1996;Zimmerer 2000). 36 The research agenda has subsequently expanded to include issues of environmental management and application (e.g., O'Riordan 1970O'Riordan , 1997 and global environmental change (e.g., Parry 1990; Silver and DeFries 1990;Turner et al 1990;Wilbanks 1994;Downing 1996;Kates et al 2001;Liverman, Yarnal, and Turner forthcoming).…”