Abstract

Accurate reconstruction of the timing and pattern of past climate variations is pivotal to a wide range of scientific studies. Climate modellers may use the results to test the functioning and/or predictive capabilities of numerical climate simulations. Earth scientists use them to assess the role of climate forcing on a range of earth surface processes, operating over very different timescales. Archaeologists have long considered the possible influence of climate on human evolution and dispersal. Part of the remit of environmental science is to understand how climatic factors regulate processes of major societal significance, such as groundwater recharge, aridification and flood recurrence. These various studies all depend upon the availability of reliable climatic histories, and an understanding of how the global climate system works. However, recent discoveries are increasingly pointing to a serious and pervasive problem in this regard, especially with regard to how we measure the global environmental response to abrupt climatic events (those that take place in less than one hundred years). In this talk I will endeavour to address, and to stimulate debate about, three things: (a) the nature of the problem, by referring to recent advances in our understanding of the history of global climate variability during the late Quaternary (the last c.150,000 years or so); (b) the promise that new approaches in geological dating offer for delivering more precise chronologies of past climatic variation; and© the challenges that lie ahead, and that need to be met, before the stamp of climate change on the geo-archaeological record can be appraised with more assurance.