P2F-RD1

The project Past-to-Future (P2F) aims at radically advancing our knowledge of past climatic conditions to better understand Earth’s climate response to different kinds of forcing, with considerable focus on potential abrupt climatic transitions and the crossing of tipping points. To this end, P2F will integrate information from paleoenvironmental proxy data, from Earth system models (ESMs), and from rigorous theoretical approaches. Being able to reconstruct past climate evolution is a necessary step for enhancing our capacity to look into the future and, therefore, extensive improvements of state-of-the-art ESMs are needed. So far, ESMs are mainly calibrated and validated with respect to the instrumental records of the last ~170 years of relatively stable climate, while the Earth’s longer-term history is characterised by an interplay of gradual climate change, variability and critical transitions between competing states, with profound impacts on climate subsystems, ecosystems, and civilisations. Understanding the leading dynamical processes and feedbacks and in particular improving our ability to model and anticipate critical transitions in the climate and ecosystems is key to project future climate change on spatio-temporal scales relevant for societies, ecosystems and the planet. In this context, P2F will critically advance our ability to understand and anticipate the main climatic and societal impacts of the ongoing climate crisis. Specifically, P2F will extend the reach of Earth System Models and demonstrate a step change in the model development cycle of the Climate Model Intercomparison Project (CMIP), by providing fully paleo-informed models for future projection and producing a portfolio of plausible future climate change scenarios that are constrained by documented past climate changes and abrupt transitions. Finally, P2F will efficiently disseminate research outputs and engage key stakeholders in dialogue to ensure appropriate synergies are at attained.