COMMENT ON DISCUSSION OF PROXIES IN HUNTLEY (2012)
All areas of research have strengths and limitations which are readily acknowledged by the scientists involved. The reconstruction of past climates (palaeoclimates) from biological indicators contained within the fossil record (proxies) presents some specific challenges; for example key limitations might be gaps in a sedimentary sequence or post-depositional degradation of samples. Understanding and interpreting data sets in the face of these challenges require the researcher to develop a wide range of skills. Huntley (2012) focuses upon the uncertainties within palaeoclimate reconstruction which he considers to be “frequently overlooked” (p. 2) by scientists making climate reconstructions from proxy records. Specifically Huntley urges researchers to consider carefully:
- What a given proxy is actually capable of reconstructing, i.e. what climate variables controls its distribution?
- What other variables might be influencing the proxy, i.e. could there be multiple influences, might these vary through time?
- What is the spatial relevance of the proxy, i.e. macro versus micro scale?
- Can multiple proxies be compared, either within or between sites?
In other words: which and how many climatic variables can be reconstructed form any one aspect of the fossil record?
Below I review and comment on some key arguments made by Huntley (2012) related to the use of proxies in reconstructing palaeoclimates.