There is a growing realization that the greenhouse-induced warming of the planet and the intensification of the hydrological cycle will have a significant impact on human society and its economic infrastructure. The significance of the effects for Australia, and for any other community in the world, will depend upon how government agencies and planners prepare for the consequences of these predicted changes. Governments need considerable help with any decision process associated with a long-term issue such as greenhouse. Availability of information (both accurate and complete) is of crucial importance if governments are to be expected to develop national (and polynational) strategic plans to ensure the continuation of, and development of, an acceptable lifestyle over the coming decades and centuries. In this paper, the authors present the scientific and planning background to the proposal for an integrated greenhouse data management system (IGDMS) and we briefly note some policy and planning options. The IGDMS proposed here is a first step in providing government departments with the decision support/management information systems required to face the global change challenges of the next century.