After briefly summarizing the reason for concluding that conventional development has been a failure and analysing the central mechanisms responsible, this paper outlines some of the main ways in which this approach has led to serious environmental impacts. It is argued that an approach to development based on market forces and growth maximisation is one of the most significant causes of global ecological destruction. Appropriate and ecologically sustainable development require a shift to principles of development which focus on local economic self-sufficiency, independence from global economic forces and the abandonment of rich world living standards as the goal of development.