Le Geoscienze e le sfide del XXI secolo
Padova, 16-18 settembre 2025
Plenarist Abstracts
The Anthropocene: geological signals of planetary change
Jan Zalasiewicz
School of Geography, Geology and the Environment, University of Leicester, UK
Jan Zalasiewicz
School of Geography, Geology and the Environment, University of Leicester, UK
Human civilization has developed amid the relatively stability of climate and sea level, and the diverse biosphere of, the 11.7 millenia of the Holocene Epoch: the latest of many interglacial phases of the Quaternary Ice Age, and the one that shaped the world we live in.
The growth of industrialized human civilization, especially since the mid-20th century, has now put that stability into question. With the accompanying sharp rise in human numbers, energy use, technological production and globalization, have come sharp and large-scale changes to landscape, biosphere and climate. These unprecedented changes have led to the suggestion that we are now living through the beginning of a new epoch, the Anthropocene: an interval of geological time dominated by overwhelming human impacts. The term was proposed little more than two decades ago by Paul Crutzen, the Nobel Prize-winning atmospheric chemist (Crutzen 2002), and has since been widely used – and sharply debated.
Formalization of the Anthropocene on the Geological Time Scale was proposed by the Anthropocene Working Group (Waters et al. 2024) though subsequently rejected by the International Commission on Stratigraphy. But the term and concept continue to be used (Zalasiewicz et al. 2024) and its processes are, in reality, changing the geology of our planet, bringing in changes that are significant in a deep time perspective (Syvitski et al. 2020). These include physical changes most strikingly represented by the explosive growth of the 'urban stratum': the refashioning of sand, clay and limestone into our buildings, foundations and transport systems. Biological changes include the ongoing mass extinction event and the effect of invasive species, while human-made 'anthroturbation' is as extraordinary as anything in the fossil record. Chemical changes include the reshaping of the Earth's natural carbon, phosphorus and nitrogen cycles, with their associated climate and biological impacts. Indeed, some of the planetary developments, such as the rapid growth of the technosphere – inter alia to now outweigh the biosphere – are wholly new within Earth's 4.5 billion-year history.
The combined transformation is of a scale to leave a signal, in strata now forming, that will persist for many millions of years, and that have already taken the planet outside of the baseline conditions of the Holocene Epoch, and in several respects out of those of the Quaternary Ice Ages as a whole. The continuing, rapidly growing departure from Holocene conditions means the Anthropocene cannot help but remain a key concept for present and future generations of geoscientists, and more widely for interdisciplinary study of an Earth System undergoing transition.
Crutzen P. J. (2002) – Geology of mankind. Nature, 415, 23, https://doi.org/10.1007/978-3-319-27460-7_10.
Syvitski J. et al. (2020) – Extraordinary human energy consumption and resultant geological impacts beginning around 1950 CE initiated the proposed Anthropocene Epoch. Commun. Earth Environ., 1, 32, https://doi.org/10.1038/s43247-020-00029-y.
Waters C.N. et al. (2024) – Executive Summary. The Anthropocene Epoch and Crawfordian Age: proposals by the Anthropocene Working Group. EarthArXiv, https://doi.org/10.31223/X5VH70.
Zalasiewicz J. et al. (2024) – What should the Anthropocene mean? Nature, 632, 980–984.
The growth of industrialized human civilization, especially since the mid-20th century, has now put that stability into question. With the accompanying sharp rise in human numbers, energy use, technological production and globalization, have come sharp and large-scale changes to landscape, biosphere and climate. These unprecedented changes have led to the suggestion that we are now living through the beginning of a new epoch, the Anthropocene: an interval of geological time dominated by overwhelming human impacts. The term was proposed little more than two decades ago by Paul Crutzen, the Nobel Prize-winning atmospheric chemist (Crutzen 2002), and has since been widely used – and sharply debated.
Formalization of the Anthropocene on the Geological Time Scale was proposed by the Anthropocene Working Group (Waters et al. 2024) though subsequently rejected by the International Commission on Stratigraphy. But the term and concept continue to be used (Zalasiewicz et al. 2024) and its processes are, in reality, changing the geology of our planet, bringing in changes that are significant in a deep time perspective (Syvitski et al. 2020). These include physical changes most strikingly represented by the explosive growth of the 'urban stratum': the refashioning of sand, clay and limestone into our buildings, foundations and transport systems. Biological changes include the ongoing mass extinction event and the effect of invasive species, while human-made 'anthroturbation' is as extraordinary as anything in the fossil record. Chemical changes include the reshaping of the Earth's natural carbon, phosphorus and nitrogen cycles, with their associated climate and biological impacts. Indeed, some of the planetary developments, such as the rapid growth of the technosphere – inter alia to now outweigh the biosphere – are wholly new within Earth's 4.5 billion-year history.
The combined transformation is of a scale to leave a signal, in strata now forming, that will persist for many millions of years, and that have already taken the planet outside of the baseline conditions of the Holocene Epoch, and in several respects out of those of the Quaternary Ice Ages as a whole. The continuing, rapidly growing departure from Holocene conditions means the Anthropocene cannot help but remain a key concept for present and future generations of geoscientists, and more widely for interdisciplinary study of an Earth System undergoing transition.
Crutzen P. J. (2002) – Geology of mankind. Nature, 415, 23, https://doi.org/10.1007/978-3-319-27460-7_10.
Syvitski J. et al. (2020) – Extraordinary human energy consumption and resultant geological impacts beginning around 1950 CE initiated the proposed Anthropocene Epoch. Commun. Earth Environ., 1, 32, https://doi.org/10.1038/s43247-020-00029-y.
Waters C.N. et al. (2024) – Executive Summary. The Anthropocene Epoch and Crawfordian Age: proposals by the Anthropocene Working Group. EarthArXiv, https://doi.org/10.31223/X5VH70.
Zalasiewicz J. et al. (2024) – What should the Anthropocene mean? Nature, 632, 980–984.
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On the societal relevance of economic geology
Wolfgang Maier
Wolfgang Maier
School of Earth and Environmental Sciences, Cardiff University, UK
Exploitation of minerals and rocks was essential to early humans, the rise of ancient civilisations and the agricultural and industrial revolutions. Some mineral deposits are of such immense value that they influenced the economic and political development of entire sub-continents (e.g. Bushveld Complex and Witwatersrand gold fields in Southern Africa). Mining also causes environmental degradation, and competition over minerals often led to conflict and war. Because minerals are key to the green energy transition, global competition for their exploitation is currently intensifying again. The EU introduced a range of policies to enhance internal exploration and mining and to become less dependent on imports of so-called critical metals, i.e. those that are of high importance for the transition to the low-C (or net zero) society and the digital economy, and that have an elevated risk to their supply chains. In this talk, I will review predictions of future metal demand in relation to global megatrends including population growth, mineral use and climate change. I will show examples where critical metals are currently found and mined, and where potential for future discoveries exists.
The key challenge arising for the European mining and exploration sector is to maintain high standards of ethical practice and environmental sustainability to increase social acceptance for exploration and mining, thereby enabling our industries to increase internal sourcing of raw materials. In addition, there are technical challenges to overcome; Most shallow (near-surface) deposits have likely been found, discovery rates are falling, exploration expenditure and thus discovery costs increase, and depth of discovery increases. Furthermore, most exploration expenditure is still focussed on gold, arguably of lesser societal importance than many other metals. Also, volatility in commodity prices renders investment in mineral exploration and mining relatively risky. This restricts investment in the minerals sector from major wealth funds, with particularly negative implications for the junior exploration sector.
What other options exist to secure future raw materials supply? It has been suggested that increased recycling rates may require less mining in the future. However, while recycling is important for some commodities, e.g. steel, it is currently highly inefficient for most metals. At the same time, hopes to significantly reduce global metal consumption appear unrealistic as long as living standards remain highly unequal across the globe. On a more optimistic note, many countries and areas remain underexplored for minerals, offering opportunities for significant discoveries, particularly at depths exceeding a few 100 m. Also, exploration and mining are becoming more efficient. Our understanding of ore forming processes is improving, as are geophysical and geochemical techniques. Prospectivity models based on the minerals system approach combine mappable exploration criteria on GIS platforms and use machine learning techniques to identify prospective tracts. Advances in AI will ensure that these become more efficient, particularly as several key resource countries (e.g. Australia, Finland, Canada) provide large open access geo-databases.
The key challenge arising for the European mining and exploration sector is to maintain high standards of ethical practice and environmental sustainability to increase social acceptance for exploration and mining, thereby enabling our industries to increase internal sourcing of raw materials. In addition, there are technical challenges to overcome; Most shallow (near-surface) deposits have likely been found, discovery rates are falling, exploration expenditure and thus discovery costs increase, and depth of discovery increases. Furthermore, most exploration expenditure is still focussed on gold, arguably of lesser societal importance than many other metals. Also, volatility in commodity prices renders investment in mineral exploration and mining relatively risky. This restricts investment in the minerals sector from major wealth funds, with particularly negative implications for the junior exploration sector.
What other options exist to secure future raw materials supply? It has been suggested that increased recycling rates may require less mining in the future. However, while recycling is important for some commodities, e.g. steel, it is currently highly inefficient for most metals. At the same time, hopes to significantly reduce global metal consumption appear unrealistic as long as living standards remain highly unequal across the globe. On a more optimistic note, many countries and areas remain underexplored for minerals, offering opportunities for significant discoveries, particularly at depths exceeding a few 100 m. Also, exploration and mining are becoming more efficient. Our understanding of ore forming processes is improving, as are geophysical and geochemical techniques. Prospectivity models based on the minerals system approach combine mappable exploration criteria on GIS platforms and use machine learning techniques to identify prospective tracts. Advances in AI will ensure that these become more efficient, particularly as several key resource countries (e.g. Australia, Finland, Canada) provide large open access geo-databases.
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Ocean and Climate: Thirty Years of Multi-Scale and Interdisciplinary Research
Sabrina Speich
Sabrina Speich
Ecole Normale Supérieure - Department of Geosciences, Laboratoire de Météorologie Dynamique, Paris, France
The ocean plays a central role in regulating Earth's climate, absorbing approximately 90% of the excess heat and 25% of the CO2 produced by human activities. This buffering capacity depends on a complex set of physical processes operating across a wide range of spatial and temporal scales—from large-scale circulation to small-scale eddies and fronts—that are often unresolved in climate models.
These processes, together with air–sea interactions, are critical in controlling the uptake and redistribution of heat and carbon within the ocean. The Atlantic Meridional Overturning Circulation (AMOC), for instance, is a key component of the global climate system, yet recent observations reveal a much richer and more variable behavior than what is simulated by current models—likely due in part to the lack of representation of fine-scale dynamics.
In this talk, I will discuss how the integration of multi-scale observations, high-resolution modeling, and new theoretical frameworks is essential to improve our understanding and prediction of climate evolution in a rapidly changing world.
These processes, together with air–sea interactions, are critical in controlling the uptake and redistribution of heat and carbon within the ocean. The Atlantic Meridional Overturning Circulation (AMOC), for instance, is a key component of the global climate system, yet recent observations reveal a much richer and more variable behavior than what is simulated by current models—likely due in part to the lack of representation of fine-scale dynamics.
In this talk, I will discuss how the integration of multi-scale observations, high-resolution modeling, and new theoretical frameworks is essential to improve our understanding and prediction of climate evolution in a rapidly changing world.
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