Frontiers in Palaeobotany: Plant fossils and their role in predicting future climate change

Abstract

Palaeobotany has a long history of providing insights into past climates. As the issue of climate change becomes of global concern it is essential that the predictive capabilities of numerical climate models become more precise, accurate and robust with regard to how fundamental aspects of the Earth system might react to future atmospheric compositions, vegetation and ocean dynamics. The only way of testing model capabilities for conditions that depart from those of the present is to retrodict the past, particularly for times when greenhouse gas loadings were as they are now, and as they are likely to be over the next few centuries. This means successfully modelling pre-Quaternary climates. For model validation over land surfaces the most useful proxies in terms of quantification of a range of climate variables are fossil plants. The characteristics of palaeobotanical climate proxies for “deep time” are reviewed and examined. Both nearest living relative and physiognomic techniques are then applied to the Vilui Basin, Russia which represents an ancient (Late Cretaceous) continental interior where models display an inability to replicate conditions revealed by the proxies, and exhibit an inherent conservatism that is likely to underestimate the degree of future change experienced by such regions.