Climate change and human history. Some indications from Europe, ad 400-1400.

The influence of climate change on history is discussed in such a way as to take account of recent research while seeking to herald, rather than foreclose, the much more focussed and definitive debates that will become possible by the turn of the century. By then, much more elaborated time series of global climatic change over the last several millennia should be available. The period chosen for examination is the 1000 years or so following the collapse of Roman Europe. During this time, civilization seems to wane, wax and wane again, very much in phase with the climate deteriorating, improving and then deteriorating once more. What this overview high-lights is the great vulnerability to climatic perturbation of societies that are marginally poised for other reasons. In several major respects, the whole of world society will be marginal in the 21st century.