Agenda 21 recommends supporting national, subregional, regional and international research programmes on marine and terrestrial systems, strengthening global terrestrial databases of their components, expanding corresponding systems for monitoring their changing states and enhancing predictive modelling of the Earth system and its subsystems, including modelling of the functioning of these systems assuming different intensities of human impact. The research programmes should include the programmes mentioned in other Agenda 21 chapters which support mechanisms for cooperation and coherence of research programmes on global change.