Chironomids can be reliable proxies for Holocene temperatures. A comment on Velle et al. (2010)

Abstract

Velle et al. (2010) discussed discrepancies between Scandinavian Holocene chironomid-inferred temperature estimates, which they attribute to the response of chironomids to environmental variables other than temperature and to taxonomic shortcomings. They suggest ways in which the reliability of chironomid-based paleotemperature reconstructions could be improved by taking into account ecological complexity. While we agree with many of their recommendations, based on the results of other work, we think their paper is unnecessarily pessimistic regarding the ability of existing chironomid-based temperature inference models to provide reliable estimates of past temperature. We offer a critique of the main points discussed by Velle et al. (2010) and provide evidence that chironomid-based temperature inference models can reliably reconstruct mean July air temperature in the Lateglacial and Holocene over millennial and centennial timescales.