The full programme book (PDF) - Royal Geographical Society

T3
Glacier-based climate reconstructions: approaches, limitations, and future
directions
I.D. Barr 1 *, C. Boston 2 , D. Pearce 3 and M. Standell 4
1 Queen’s University Belfast
2 University of Portsmouth
3 University of Worcester
4 Loughborough University
Geomorphological reconstructions of mountain-scale ice masses are widely-used as
indicators of palaeoclimate. This approach has a foundation in the mid-20th century but
there has been a recent proliferation of studies, coinciding with the development of remote
sensing and GIS technologies. Despite this wide use, methods are rarely formalised, and
sources of uncertainty are rarely explicitly discussed.
Here we address this lack by outlining some of the principal sources of uncertainty and
error in glacier-based climate reconstructions. Focus is placed on uncertainties with
delimiting glacier dimensions, estimating palaeo equilibrium-line altitudes (ELAs), and
making subsequent quantitative links to palaeoclimate. We suggest that the process of
reconstructing glacier dimensions offers the greatest potential for error in this process;
whilst the choice of ‘appropriate’ ELA estimation method or procedure for linking to climate
(e.g. whether to use empirical precipitation/temperature relationships or a degree day
model) only serve to add to this uncertainty. We conclude by suggesting some ‘best’
methods and possible future research directions, and, in the absence of an ideal
methodology, encourage practitioners to be explicit and transparent about their
methodologies, to highlight areas of uncertainty in their reconstructions, and to report all
estimates of glacier dimensions, ELA, and palaeoclimate with associated error bars.
Keywords: glacier reconstructions; palaeoclimate; ELA; methods; error; uncertainty.