Advanced Review Conceptions of time in (paleo)climate science and some implications Chris Caseldine ∗ Palaeoscientists of necessity deal with time as a fundamental part of the research process and have developed understandings within the discipline of how to deal with a range of timescales from the deep time of Archaean geology to recent time, that is the last few centuries. Time has however largely been seen as providing a chronology, the ability to place events in sequence and through the implementation of various dating techniques to relate these sequences across space, providing fun- damental information toward understanding cause and effect within the Earth sys- tem. Variability in the units of time, the differences between radiometric and side- real or calendrical years is accounted for and not deemed significant. When dealing with other disciplines, either through research into the relationship of past societies to climate change, or when contributing to the concerns over future directions of climate problems arise in attempting to communicate the nature of timescales. The real issue is to reinforce the idea of change as a basic quality of the climate system, something that can occur very rapidly. It is open to question whether a concentra- tion on timescales of climate change is proving a distraction in terms of commu- nication from the most important issue. Change is a fundamental property of the global climate system, and from our paleoscience knowledge it is clear that change will continue into the future and could well be very rapid.  2012 John Wiley & Sons, Ltd. How to cite this article: WIREs Clim Change 2012. doi: 10.1002/wcc.178 INTRODUCTION Nobody cares about 50 years from now (Larry King, quoted in Hansen, 2009). 1 C limate scientists are being drawn increasingly into areas of public policy and need to communicate their science to an ever widening range of stakeholders, from other scientists and academics to the general public. This creates potential for misunderstandings and highlights a lack of appreciation of how other groups contextualize their information. For palaeoscientists, those concerned with past climates and their significance for understanding future climate trajectories, researchers who have usually had very little exposure to such problems, this issue can be acute. An important aspect of this communication ∗ Correspondence to: C.J.Caseldine@ex.ac.uk Geography, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, Cornwall, UK issue is how to deal with time, a feature that underpins palaeoscience, but which has attracted relatively little critical appraisal in the past; although in other disciplines, archaeology for instance, this has been a subject of continuing debate 2,3 over at least two decades. Within paleoscience researchers work on differ- ent aspects of time from the deep time of Archaean geologists, to what may be termed recent time stud- ied by palaeoecologists and palaeoclimatologists, a period often synonymous with the Quaternary—the last 2.58 Ma, 4 or more appropriate to current debates, the last 11,700 years of the Holocene. 5 The discovery of deep time, ‘conventionally’ (according to Gould 6 ) attributed to James Hutton in 1787, proved to be a major paradigm shift in the earth sciences. This allowed geologists to move away from the straitjacket of a Biblical chronology defined by Archbishop Ussher in 1650 that saw the earth created in October 4004 BC, 7,8 and be able to interpret strata in terms of almost  2012 John Wiley & Sons, Ltd.