Quaternary climate archives and proxy uncertainty
|Convener: Nathalie Fagel | Co-Conveners: Armand Hernández , Timothy Lane , Laia Comas-Bru , Kathryn Adamson , Jeremiah Marsicek|
Palaeoclimate proxies developed from biological and geological archives have the potential to be highly sensitive to environmental changes. They are key to understanding past climate beyond the limits of instrumental observation, allowing robust local, regional, and global palaeoclimate records to be produced from terrestrial and marine settings. Proxy records are further used to reconstruct synoptic climate systems in the past, such as the El Niño Southern Oscillation or North Atlantic Oscillation, and proxy data is used by climate modelers for validation.
A multiproxy approach is often employed, which relies on measuring numerous biological, geochemical, sedimentological, and/or mineralogical proxies in the same archive, and sheds light on the mechanisms and feedbacks of global and regional climate change and/or on how these proxies may be controlled by large-scale atmospheric circulation modes associated with past climate changes.
However, environmental change is not only induced by regional or global climate variations but also by, usually more local, tectonic events or human perturbations. In most cases, a spatial comparison of paleoclimate records developed from multiple archives provides a framework to distinguish local and regional climate variability from global change.
Proxy reconstructions also contain uncertainty that is often not presented in explicit, clear terms. Sources of uncertainty in proxy data include 1) the precision of measurement during analysis, 2) the error or ambiguity involved in descriptive or non-analytically derived proxy measurements, 3) and the uncertainty of calibrating any particular proxy with respect to climate, to name a few. Further, many proxy techniques are inherently biased towards seasonal climate conditions, which provides challenges for the comparison of regional to global climate reconstructions developed with myriad techniques.
This session focuses on Quaternary paleoclimate reconstructions that document continental and marine climate variability using multiproxy techniques, studies that evaluate proxy uncertainty or that develop strategies to account for bias in paleoclimate proxies, proxy calibration through modern observation (monitoring), and contributions that integrate climate modelling and proxy data as a way to foster model-data comparison.