Cloudy with a chance it rained: Progress towards a proxy for palaeocloud

Cloud has profound impacts on climate, thus accurate cloud simulation is critical for accurate climate modelling. As the greatest source of uncertainty in such models, cloud drives discrepancies in the prediction of future climate. Cloud simulations are validated against recent observations; however, these records do not capture the climate space we are entering this century, limiting our ability to test model accuracy under near future conditions.

The best analogue for the 21st Century climate trajectory comes from the Pliocene. Reconstructions of Pliocene cloud regimes would provide critical validation data for climate model performance with respect to cloud. However, despite the wealth ways to reconstruct other climate variables, no method has been developed for reconstructing cloud in deep time.

We are working towards proxies capable of reconstructing past cloud, with the goal of establishing a global cloud database for the Pliocene. Our initial results demonstrate the relationship between vegetation and large-scale patterns in cloud in the modern, and tests the model derived from the modern data against palaeoclimate model vegetation and cloud.