The twin issues of food security and environmental protection for the remainder of the century will be defined by expectations that the population will continue to grow to 11 billion, mainly in less developed countries (LDCs), as well as by human behavior. This paper considers conventional analyses of food demand and compares these with wider philosophical perspectives that may modify approaches to agricultural science. The conventional approach is indicated in IFPRI research which models scenarios to 2020 and predicts an increased demand for cereal of 40% to be met by increased production mainly in LDCs, with more developed country (MDC) exports possibly falling with prices. While production seems adequate for the higher population, continued distributional and nutritional inequities are foreseen. Food production is likely to maintain priority over environmental protection in LDCs although environmental remediation should benefit from technology, particularly in MDCs. The agricultural environment represents human’s widest spread of terrestrial environmental manipulation, and its monitoring is more economic than ecological in orientation. Rising understanding of the mutual causality between the impoverishment of people and the environment may well focus more on nontechnological factors through this century than the last. Outside agricultural circles, philosophical thought has advanced beyond the anthropocentric approaches of sustainable agriculture to consider the rights of nature, including humans. Increased societal awareness of such matters may influence the overall development paradigm within which rests most of our agricultural research. A reduction in total food requirements is implied in this paradigm as agricultural self-sufficiency is accepted as socially beneficial and as food security is conceived as a universal right of access to nutritious food. Such security implies increased protection of environments in LDCs. Whether such changes occur, there is value in widening the ethical perspective of all of us associated with the manipulation of nature and the planning of human development through the 21st century.