Quaternary Environmental Change in the Tropics

The global climate changes that led to the expansion and contraction of polar ice sheets over the past two million years were associated with equally dramatic changes in tropical and sub-tropical terrestrial and marine environments. Changes in global temperature, fluctuations in sea level and alterations of the position of the major oceanic and atmospheric circulation systems led to shifts in continental vegetation zones, changes in the hydrology and ecology of tropical lake and drainage systems, and the expansion and contraction of tropical mountain glaciers and sandy deserts. Until recently, it was thought that such changes were largely a response to fluctuations in the distribution of high latitude ice cover. However, there is increasing recognition that the Tropics have acted as drivers of global climate change over a range of timescales. This is in part due to their importance in terms of solar radiation receipt and the resulting energetics of the global circulation, but also because of the role tropical oceans and ecosystems play in regulating greenhouse gases.§Despite the significance of the Tropics for global climate change debates, there has yet to be a volume that synthesises our current understanding of how tropical environments as a whole changed over the past two million years. A number of general texts, such as Bradley (1999) Paleoclimatology: Reconstructing Climates of the Quaternary (Harcourt), Goudie (1992) Environmental Change (OUP), Lowe & Walker (1997) Reconstructing Quaternary Environments (Longman), Ruddiman (2001) Earth's Climate, Past and Future (Freeman) and Williams et al. (1998) Quaternary Environments (Arnold), touch briefly on evidence from the Tropics. There are also more specialist volumes, such as Middleton & Pye (1994) Environmental Change in Drylands (Wiley), Derbyshire & Singhvi (1999) Paleoenvironmental Reconstruction in Arid Lands (Balkema), Markgraf (2001) Interhemispheric Climate Linkages (Academic Press) and Battarbee et al. (2004) Past Climate Variability Through Europe and Africa (Springer), that only focus on the evidence for environmental change for specific climatic zones or continents. Our volume aims to bridge this gap and provide the first over-arching review focussing specifically on the Tropics drawing together a literature which is widely scattered across a range of journals straddling traditional disciplinary boundaries.§The overall aim of Quaternary Environmental Change in the Tropics is to provide a readable synthesis of the major climatic and broader environmental changes that occurred in tropical terrestrial and marine systems during the Quaternary period. The volume will also consider the forcing mechanisms that may have driven these changes. In order to achieve this aim, authors who are recognised international experts in their fields have been approached and have provisionally agreed to write chapters.