Register of the Early Warning Indicators (Deliverable D4.1)

The deliverable  provides a synthesis of early warning indicators (EWIs) for major climate tipping elements, whose tipping risk is increasing under anthropogenic pressure. It combines approaches based on critical slowing down and understanding of physical processes to identify signals of impending abrupt transitions. The main contribution is the development of EWI registers for key systems (SPG, AMOC, Greenland and Antarctic ice sheets, and Arctic sea ice), compiling precursors, available and missing observations, threshold estimates, timescales, and indicator reliability. The analysis highlights significant observational gaps and uncertainties across many indicators, and offers recommendations to strengthen monitoring systems. Overall, this work establishes a structured foundation for developing operational early warning systems for climate tipping risks.

The living document with the EWI Register is available here: https://zenodo.org/records/20799814