Accelerating transformation of the unique Earth envelop -the Biosphere -under human impact puts the more and more serious problems for Humanity. From the stage of local and regional modifications of landscapes and some life sustaining processes Biosphere is entering into global anthropogenic change. The scientific community has responded to this reality by elaborating the International Geosphere-Biosphere Programme of study: Global Change. But there is a gap between investigations of the contemporary structures and' proeesses and paleographic reconstructions of the environments in Pleistocene and the first half of Holocene.
In August 1988 the Study Group on Historical Geography of Global Environmental Change was created in the International Geographical Union with the aim to develop an interdisciplinary and international framework for studies and discussions on Biosphere transformation over the last millenia, centuries and decades. These timescales are appropriate for revealing human-induced changes and comparing them with natural fluctuations in Biosphere. The following collection of papers is the first project of the new IGU Study Group. We are grateful to the Editor of GeoJournal for the proposal to prepare this special issue concerning Global Change in Historical Perspective.
The papers of this issue continue the efforts of Soviet and American geographers to review the geographical approaches to study Global Change. The results of the previous stage in bilateral co-operation are summarized by J. R. Mather and G. V. Sdasyuk. The joint monograph "Global Change: geographical approaches", forthcoming in English in the University of Arizona Press (Tucson, USA) and in Russian in Progress Publishers (Moscow, USSR), emphasizes on studies of contemporary landscapes and cycles in Biosphere including societies-nature interactions. The key notions are those of fluxes, networks, boundaries, regionalization, management of anthropogenic processes, natural disasters reduction etc.
This issue of GeoJournal accents on historical changes in human impact, landscapes evolution, alteration of biospheric processes. B. L. Turner and W.B. Meyer review the programme "Earth Transformed by Human Action" which is the important background for the programme of the new IGU Study Group. V. V. Annenkov discusses the directions of the new field in Historical Geography oriented to integration of data from the earth sciences and social sciences around the problem of biosphere transformation to noosphere over space and time. S. N. Goward assesses the experience of using remote sensing for the study of the dynamics of landscapes and biospheric processes at the scales of decades. N. F. Glazovsky initiates the study of human impact on geochemical cycles changing over time. R. G. Barry reviews the cryogenic evidence over about a century and discusses its relation to global warming trends. R. K. Klige attemps to reconstruct the changes in hydrological cycles over the history of the Earth's surface for comparing natural fluctuations with the anthropogenic ones. All above mentioned directions develop the field of Historical Geography of Global Environmental Change as the bridge between Geography and Paleogeography, between the International Geosphere-Biosphere Programm and the Human Dimensions of Global Change Programme. The tasks for geographical research in connection with IGBP are discussed in the paper by A. V. Drozdov and V.M. Kotlyakov. Unresolved questions in relation with Human Dimensions of Global Change Programme are examined by W. C. Clark.