W. Berry Lyons, Department of Geology, University of Alabama, Tuscaloosa, Alabama, USA. Clive Howard-Williams and Ian Hawes, both National Institute of Water and Atmospheric Research, Christchurch, New Zealand.

• Preface; There can be no contentment but in proceeding: Opening address to the International Workshop on Polar Desert Ecosystems 1 Overviews Polar desert ecosystems in a changing climate: A north-south perspective; Climate history of the McMurdo Dry Valleys since the last glacial maximum: A synthesis; U V radiation in polar regions 2 Terrestrial environments 3 Aquatic environments 4 Human Impacts, Indexes