Late Pliocene soils and lakes: A global data set for the analysis of climate feedbacks in a warmer world

Our understanding of future global warming under increasing human-related emissions of greenhouse gases relies heavily on prediction of climate model simulations. Although progressively more sophisticated, climate models have uncertainties in particular when simulating climates with temperatures and atmospheric CO2 concentrations unprecedented in the recent past. Soils, lakes and vegetation can have a strong impact on the climate system and are often key factors for uncertainties in modelling experiments. One approach to explore uncertainties and understand mechanisms of potential future climate change is to look at time periods in the past, for which geological data are available. The proposed project will investigate the importance of soil and lakes in a warmer, high CO2 world, by synthesising global datasets from geological records. We will focus on the Late Pliocene geological period, ca. 3.6-2.6 million years ago. With increased mean global temperatures and higher atmospheric CO2 concentrations, the late Pliocene geological period provides an 'accessible example of a world that is similar in many respects to what models estimate could be the Earth of the late 21st century' (Intergovernmental Panel on Climate Change 2007). Our new global soil and lake dataset will be used as boundary conditions in palaeoclimate modelling experiments. The outcomes of these models will then be evaluated using the existing comprehensive TEVIS dataset (Tertiary Environment and Vegetation Information System), which contains data from 202 palaeobotanical sites. By indicating weaknesses and strengths, our data-model comparison will test the importance of soils and lakes in high CO2 climate systems and will contribute to the improvement of climate models that we rely upon for simulating future climate change.