Building an international community of scientists from such diverse fields as anthropology, climatology, Quaternary geology, paleolimnology, paleontology, paleoceanography, and archaeology will require a sustained effort. The primary goals of any such activity must include facilitating communication and making information easily accessible to participants. In this regard it is useful to consider possible models for an international consortium of climate, earth, and human evolution scientists. In addition to the Stage Three Project noted above, another highly successful and relevant model is the PAGES (Past Global Changes²) program, a core project of the International Geosphere-Biosphere Program (IGBP) dedicated to promoting past global change research. The PAGES program operates through a small secretariat and 23 national member contacts, with funding from the U.S. National Science Foundation, the Swiss National Science Foundation, and the National Oceanic and Atmospheric Administration. This program promotes research on past global climate change by identifying key research opportunities through a series of focal group meetings, through sponsored workshops, and with its publications. We envision a similar structure for an international climate and human evolution consortium.

An urgent need exists for a major international initiative to recover significantly more hominin fossils, as well as the flora and fauna that are associated with these fossils. Exploration for new sites is required beyond the limited areas within continents that have been sampled so far. Such an initiative would greatly improve our understanding of

• the geographic distribution and variation of hominins;

• the phylogeny of the human lineage; and

• the first and last appearances of species, and of important archaeological or fossil evidence of human behavior.

This in turn will permit a vastly improved correlation of the significant events in human evolution with proxies for climate and other aspects of the earth system. At present, this is not possible at the level of resolution necessary if hypotheses that would relate changes in human evolution to extrinsic factors are to be meaningfully tested.

The discovery of fossil hominins, and the associated flora and fauna, has often been a random process resulting from chance occurrences, although there have been a few more deliberate and systematic exploration efforts. For example, remote sensing techniques were used in Ethiopia to predict new fossiliferous out-