From 18-20 November 2025, the ASPECT project, together with the European projects EXPECT and Impetus4Change (I4C), and the WCRP’s DCPP and EPESC groups, co‑organised the UPCLIV workshop – Understanding and Predicting Annual to Multi‑Decadal Climate Variations. This international workshop, taking place in Bologna, Italy (with online participation), brought together over 100 researchers from across Europe and beyond to share and improve knowledge on climate variability and predictability..

Climate variability on annual to multi‑decadal timescales (1-30 years) strongly influences climate risks, including prolonged droughts, shifts in temperature patterns and periods of increased extremes. However, the processes that drive these variations, and the limits of their predictability, are still not fully understood. UPCLIV sought to address this challenge by creating a forum to explore how attribution and prediction can be better integrated, helping to strengthen confidence in climate information for the coming years to decades.

Over three days, participants discussed a wide range of topics, including the evaluation of climate predictions, the role of external drivers and internal variability, and the mechanisms that underpin predictability. Sessions also explored the prediction of climate extremes and the use of emerging approaches, such as machine learning, to complement physical understanding and improve the interpretation of climate signals.

Beyond individual scientific results, UPCLIV placed strong emphasis on collaboration. The workshop strengthened links between projects and research communities working on similar questions, helping to identify opportunities for shared methods, joint analyses and future activities.

For ASPECT, UPCLIV directly supports the project’s goal of advancing seamless climate predictions by improving understanding of predictability and fostering exchange across the climate science community. The workshop highlighted both recent progress and remaining challenges, underlining the importance of sustained collaboration to improve climate knowledge and its relevance for society.