2025-2026 Lecturer: Valerio Lucarini

Valerio Lucarini

University of Leicester

Biography

Valerio Lucarini was born in Ancona (Italy) in 1976. He studied physics at Scuola Normale Superiore (Pisa) and at the University of Pisa. He obtained in 2002 a MSc in Climate Physics and Chemistry at MIT and a PhD in Physics at the University of Eastern Finland. He has held academic positions at the University of Bologna, at the University of Hamburg, and at University of Reading, where he founded the Centre for the Mathematics of Planet Earth. Since 2024 he is Professor of Applied Mathematics at the University of Leicester, where he leads the Computational and Mathematical Modelling research group.

He has supervised over 15 PostDocs, 15 PhD students and over 20 MSc students. Some of them have received important accolades from the European Space Agency, European Geosciences Union, and American Geophysical Union and are scientific leaders in the broad area of nonlinear geophysics and climate dynamics.

Valerio is the recipient of the 2010 Arne Richter Award and of the 2020 L.F. Richardson Medal of the European Geosciences Union, of the 2018 Whitehead Prize of the London Mathematical Society. He has delivered the 2021 Lorenz Lecture at the Annual Meeting of the American Geophysical Union, has received the 2022 SIAM Mathematics of Planet Earth award and the 2024 IUGG Keilis-Borok medal. He has held visiting positions in P.R. China, France, Germany, Hungary, and Russia. He is lead author for one of the chapters of the IPCC AR7 WG1 report.

After many years of participation to the editorial board of Nonlinear Processes of Geophysics and Earth System Dynamics, Valerio currently holds editorial roles for Physical Review E and Physical Review Letters. Between 2024 and 2025, Valerio has been the chair of the Topical Group on Physics of Climate of the American Physical Society.

He has organised many events for training and dissemination, including advanced schools in Les Houches (France) and at ICMS in Edinburgh (UK), and scientific programs at the I. Newton Institute in Cambridge (UK), and at the Institut Poincaré in Paris (France). Valerio has held an individual grant form the European Research Council and is currently involved in several UK-based and international projects delving into climatic tipping points, i.e. ClimTIP, Past2Future (Horizon Europe), PREDICT (ESA), AdvanTIP (ARIA). Valerio is author of over 160 publications in peer-reviewed journals and 2 books.


Abstract: Metastability Properties of the Earth's Climate: a Multiscale Viewpoint

The ultralow frequency variability of the Earth's climate features an interplay of typically long periods of stasis accompanied by critical transitions between qualitatively different regimes associated with metastable states. Such transitions have often been accompanied by massive and rapid changes in the biosphere. Multiple transitions between the coexisting warm and snowball climates occurred more than 500 Mya and eventually led to conditions favourable to the development of multicellular life. The coexistence of such states is due to the instability associated with the positive ice-albedo feedback, Yet, this behaviour repeats itself across a wide range of timescales, spatial domains, and physical processes. Building on Hasselmann's program, we propose here to interpret the time-evolution of the Earth system as a trajectory taking place in a dynamical landscape, whose multiscale features describe a hierarchy of metastable states and associated tipping points. We introduce the concept of climatic Melancholia states, saddle embedded in the boundary between the basins of attraction of the stable climates and explain under which conditions they act as gateways of noise-induced transitions. Using a hierarchy of numerical models, we discuss in detail the dichotomy between warm and snowball climate by bringing together the deterministic and stochastic viewpoint on the related global stability properties. We then discuss the paleoclimatically relevant case where multiple competing climatic states are present and show the relevance of our angle for interpreting proxy data. Finally, if time allows, we will present some very recent results suggesting that our viewpoint might explain some intriguing aspects of the dynamical features of the tipping points of the Atlantic Meridional Overturning Circulation.