This paper introduces a special edition of The Geographical Journal on the theme of 'environmental transformations in developing countries'. Geographical research into human-environment relations is well established. However, many recent studies of political ecology or constructivist approaches to environment either overlook biophysical aspects of environmental change, or uncritically accept 'orthodox' explanations of physical degradation without appreciating the social and political construction of such models. This paper, and those following, attempt to outline ways in which environmental research may remain sensitive to political and cultural debates, yet also give insights to practical environmental management of biophysical resources 'externally real' to human experience. It is argued that understanding human impacts on environment may only be achieved through long-term environmental histories compiled using locally-based 'hybrid' social and physical research methods; plus an awareness of the social and political construction of environmental 'orthodoxies' by powerful domestic and global agendas. As such, 'transformations' may be viewed as both physical changes in factors such as land cover or health hazards; but also as the socio-economic transitions in the driving forces of environmental degradation and perceptions of risk which in turn fuel new orthodoxies in research and policy.