Dr Helen Ranner
I am a palaeoecologist with particular expertise in: palynology; reconstructions of past climate, particularly during periods of rapid climate change; tephrochronology; and archaeobotanical interpretation. At present, I am working as a Postdoctoral Research Assistant, in the School of Biological Sciences, with links to the Institute of Hazard, Risk and Resiliance. My current research is concerned with reconstructing Neoglacial climate cooling using pollen as a proxy, and integrating this phenomenon within the broader context of the ‘Tipping Points’ project. Tipping Points is a multidisciplinary, Leverhulme-funded project, one of the flagship projects being undertaken by The Institute for Hazard Risk and Resilience.
Tipping Points: Rapid Neoglacial transitions in the North Atlantic - Work Package 1
Researchers: Professor Anthony Long and Dr Eleanor Maddison (Department of Geography); and Professor Brian Huntley and Dr Helen Ranner (School of Biological and Biomedical Sciences).
A rapid climatic cooling, that occurred c.5000 BP, has been identified in records of global temperatures, and local IRD records from east Greenland; the causes of this event have not yet been identified. The usual candidate for driving rapid change, i.e. abrupt changes in incoming solar radiation, was not responsible, since this is known to have been gradually declining at this time. We are examining the spatial and temporal pattern of this event, in order to explore the possibility that this climate shift, rather than being forced by drivers external to the climate system, was driven by internal mechanisms which progressively caused the system to evolve to the point of very rapid change, a potential ‘tipping point’. We will use our climate system information in collaboration with other researchers in the project: mathematicians will explore mathematical representations of this data, and the extent to which ‘tipping point’ behaviour is displayed; researchers from anthropology and marketing science, will look at how we talk about the term ‘tipping points’ in connection with the current climate system; and finally, researchers from Work Package 5 will think through the implications for anticipation and preparation with respect to future climates that may be inherently less predictable due to ‘tipping point’ behaviour.
Ranner, P. H., Allen, J. R. M. & Huntley, B. 2005. A new early Holocene cryptotephra from northwest Scotland. Journal of Quaternary Science 20(3): 201-208.