Holocene Climate Research – Progress, Paradigms, and Problems

Abstract

8 | H. John B. Birks .."normal" science. The spatial patterns of scientific progress are less explored by science historians, but Crane's (1972) "invisible college" effect is clearly important. In this, major researchers and their laboratories develop as nuclei of scientific influence through their methodologies, publications, presentations, research students, and visiting researchers. Visitors assimilate the methods and concepts of the center they have visited, and transfer the learning and experience to their own laboratory and research group. Patterns of scientific progress can often only be explained, in part at least, by the "invisible college" effect and by considering who was where when. For example, many developments in Quaternary pollen analysis in the past 50 years are only explicable in terms of the "invisible college" effect (Birks 2005).Holocene climate research has witnessed several major paradigm shifts in the past 200 years as a result not only of new ideas and conceptual breakthroughs, but also because of new and improved techniques, studies of different climate proxies, increased scientific rigor, improved project design, increased quantification, greater attention to detail, and investigations in different geographic areas and climate regimes (e.g. low latitudes, high latitudes, high altitudes, arid areas). The effects of "invisible colleges" and the inevitable geographic concentration of research effort were clearly important in the development of Holocene climate research, especially in the early pioneering stages.This chapter provides a historical overview of progress and associated paradigm shifts in Holocene climate research. My review is inevitably incomplete for several reasons. First, it reflects my geographic parochialism as there is an inevitable bias towards areas where I have had some direct research interest and experience. Second, it reflects a methodologic bias with an inevitable bias towards terrestrial proxies and Holocene terrestrial paleoecology of which I have had some direct experience. Third, the recent primary literature is so vast that I have mainly cited recent reviews and books rather than original research papers to keep the bibliography a manageable size. Fourth, I pay greatest attention to the early pioneering studies and research stages and the early publications than to the later stages, several of which are being actively pursued today by many researchers. This concern with the pioneering studies is because there is an increasing tendency in these days of the Internet and electronic sources, such as Wikipedia, for the early primary literature and the early pioneering researchers to be forgotten, or at least largely ignored. I apologize for any major omissions in the geographic areas, methodologic developments, research studies, and literature discussed here, and for any unevenness in my accounts of the different stages in Holocene climate research. Progress and paradigm shiftsPioneering Holocene climate research was, I suspect, motivated by natural curiosity abou...

Alpines, trees, and refugia in Europe

“…A surprising number of alpines within the British flora descend to low altitudes (< 50 m) or even to sea level in these naturally open habitats (Table 4). Summer and winter temperatures reached their Holocene maximum throughout much of northern and central Europe about 6-8 kyr ago, with summers about 2-2.5 °C and winters 1-1.5 °C warmer than today (Birks 1988(Birks , 2008. Presumably at this time, the forest and scrub zones reached their maximum altitudes (Birks 1988).…”

Strengths and Weaknesses of Quantitative Climate Reconstructions Based on Late-Quaternary Biological Proxies

“…The early studies of Blytt (1881), Andersson (1909), Iversen (1944), von Post (1946), and others using plant macrofossils, animal remains, pollen assemblages, and peat stratigraphy laid the foundations for many of the current ideas about late-Quaternary climate changes (see Birks 2008;Birks & Seppä 2010 for historical reviews).…”

“…Virah-Sawmy et al 2009cWillis & Bhagwat 2010;Willis et al 2010b), lags in biotic responses (e.g. Birks & Birks 2008), baseline conditions (e.g. Willis et al 2010a), and tree-population collapse (e.g.…”

“…This multi-proxy approach can allow the direct study of biotic responses to climate change in the past (e.g. Birks & Birks 2008) and the testing of hypotheses about, for example, the relative roles of climate and catchment variables in influencing within-lake biotic and abiotic records (e.g. Lotter & Birks 2003).…”

“…pollen and, by inference, terrestrial vegetation, to the inferred climate changes are studied and questions of response times, lags, and rates of turnover can be studied and quantified (e.g. Birks & Birks 2008). …”