As part of its mandate, GAIM is to explore and analyze key components of the Earth system. The enhanced understanding so gained would provide the scientific basis for more robust quantitative modelling of the Earth system. Several key topics have been identified and a few are described here. Biome6000 involves the reconstruction and modelling of global ecosystems at the last glacial "optimum" 6000 years before present (ybp). This involves both data set construction and model development and application. A second key issue is the role of wetlands in global biogeochemical cycles. While there are some inventories of wetlands constructed for a variety of environmental, political, and scientific needs, they do not include the kind of information necessary to assess the role of wetlands in global biogeochemistry. Consequently, GAIM led a workshop to assess the biogeochemical functions of wetlands and their role in the Earth system. A third topic for analysis is the exchange between climate and ecosystems. The RICE project was directed toward better quantifying the biogeochemical and biogeophyisical relationship between the terrestrial biosphere and regional/global climate. Each of these specific analysis activities prepares the foundation for more reliable Earth system model development.