Despite improved understanding of global and regional climate change and increased model complexity, the relative contribution of different feedbacks (clouds, ocean circulation, vegetation and its coupling with water and carbon cycles, ice…) continues to vary from model to model, leading to mismatches between climate reconstructions and simulations. Acquiring new Quaternary paleoclimatic records and comparing them with model results is, more than ever, the basic science needed to explain current climate change and improve climate projections.
In this lecture, María Fernanda Sánchez Goñi, Professor of Paleoclimatology, briefly introduced the discovery of the ice ages, the astronomical theory explaining them, and the unexpected identification of abrupt climate variability (millennial-to-centennial) in the 1980s.
After summarizing the evolution of global climate over the last million year, she showed its impact on different regions of the planet. She highlighted the mismatch between past climates and model simulations and, in particular, the problems linked to modelling regional responses to past global climate changes, for example in monsoon regions.
These issues have strong implications for future climate models, projections of sea level rise and regional impact of climate change. Basic research on the Quaternary is still needed to evaluate model simulations and improve climate projections.
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Background
Research on recent geological periods, during which the Earth has been subjected to cyclic and significant ice sheet development, has been instrumental in identifying the frequency and mechanisms of past natural climate changes.
The study of the most recent deposits of the Quaternary, the period covering the last 2.6 million years, has demonstrated the role of humans in the current climate change. None of the researchers who pioneered the study of Quaternary deposits in the Alps and highlighted repeated glacier advances and retreats, could have imagined the scientific and societal implications of their contribution. Without their and following discoveries present day climate scientists would not be able to propose that Earth climate is possibly crossing a crucial tipping point.
Curiosity to understand the evolution of the Earth’s climate was their main motivation. Almost three centuries ago, Quaternary studies were already contributing, unknowingly, to present research on sustainability.
About the speaker
Professor of Palaeoclimatology at the Ecole Pratique des Hautes Etudes-Paris Science Lettres (EPHE, PSL University); works at the EPOC laboratory (Environnements et Paléoenvironnements Océaniques et Continentaux) at the University of Bordeaux
E-mail address : maria.sanchez-goni@u-bordeaux.fr
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ISC Distinguished lecture series
Promoting discussion and debate around the importance of basic science and their relation to the Sustainable Development Goals