We are transitioning towards a climate state on Earth featuring rapid changes in response to anthropogenic greenhouse gas emissions and land-use change, with severe observable and projected impacts on the occurrence of extreme weather events and increasing risk of crossing large-scale tipping points. Neither the transition nor the long-term climate state has been observed by (human-made) measurements before, making information on past climatic states increasingly more important to help anticipate future Earth System change. Paleoclimate records have enormously expanded over the past decades, and provide extremely rich information about physical, cryospheric, biological, and ecological processes on many spatial and temporal scales. Yet, it has been difficult so far to directly transform this knowledge on past processes into a more confident evaluation of future projections for the Earth system.
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 Earth System Models (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.
We invite contributions that
- use knowledge of past climates to advance our understanding of climate variability, abrupt changes and climate response to greenhouse gas changes and other forcing on spatio-temporal scales relevant for societies, ecosystems and the planet as a whole;
- make use of information from paleoenvironmental proxy data, from past civilisations, from ESMs, and from rigorous theoretical approaches - individually or combined;
- explore modern approaches to incorporate palaeoclimate information into the development processes of ESMs of varying complexity;