SUMMARY
Improvements in public health services, sanitation, and disease control have contributed to ageing populations in industrialised countries, particularly over the past half century. While these trends should be regarded as positive indications of individual sustainable development, or successful ageing, they also represent potential threats to success of global sustainable development. This paper presents a biodemographical analysis of the recent ageing trends, by discussing individual and global sustainable development in the context of the various biological processes responsible for increases in longevity. It then poses the possibility that an ageing population, by increasing the number of people dependent on environmental, medical, economic, and social resources, will make global sustainability more difficult to achieve, creating obstacles in the ability of future generations to meet their own resource needs. Ultimately, we suggest increasing independence and societal interdependence as solutions to intergenerational tensions and to the potential conflict between individual and global sustainable development.