Abstract:

Reconstructing past climates is critical for understanding the full range of Earth system responses to external forcing. The two tools available to us to undertake this task are climate models, which can be used to simulate ancient climatic conditions, and proxy data, which record climate changes through geochemical, sedimentological, or biological information. Proxy data record what actually happened, but they are not evenly distributed in time or space and can carry large uncertainties. Models provide a full-field view of past climates, but as simulations, they are only a best guess at what might have happened and are also subject to bias. Paleoclimate data assimilation provides a solution, as it combines these two pieces of information in order to leverage both model and proxy information. In this talk, I will review the paleoclimate data assimilation projects that our group has undertaken in the past few years and what we have learned about past and future climate change as a result.