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1. Society and the destabilisation of the ecosystem Earth An ecosystem consists of communities of interacting species and the physical environment on which they depend. Although it is well accepted that Earth consists of many different ecosystems, human societies much less readily recognize that Earth itself is an ecosystem, dependent on interacting species and consisting of finite resources (Vignieri & Fahrenkamp, 2018). Humans are part of this ecosystem, and have recently come forward as a dominant species in terms of their physical and biological impacts. These can mainly be related to waste production and land-use changes resulting from a rapid extraction of natural resources. 2. Geology fundamental to ecosystems and society Geology determines, together with latitude, the external conditions of ecosystems. Indeed, geological processes have shaped the surface of the Earth through tectonic uplift, subsidence, and erosion, while plate tectonics determines the distribution of land and oceans. Volcanism, tectonic uplift, and the cycles of sedimentation, burial and metamorphism, determine which rocks surface, forming the primary substrate. Access to water depends on the hydrogeological cycle, which runs fast in the atmosphere and through surface waters, but also includes infiltration and buffering in aquifers, forming reliable and long-lasting sources of water. In a similar way, also the carbon cycle spins fast in surficial gear, while the geological one is slow and fundamental. Part of the carbon bearing remains of life on Earth, such as carbonate shells or organic matter, were deeply buried and fossilised. This extraction of carbon from the atmosphere had a profound impact, reducing carbon dioxide to present-day levels. Compared to these natural processes, anthropogenic processes have immediate effects. Humans have found a particular way to distinguish themselves very recently from other, contemporary life forms, in that they have established societies that rely on the ability to access and use geological resources. 3. The unsustainable basis for current society Since humans learned to unlock geological resources at a large scale, population density increased and the impact since the industrial revolution has particularly been drastic. Starting from the 20th century, the environmental impact and depletion of natural resources were identified as side effects of the free-market driven, unlimited growth-focussed economy. However, as the Earth and its resources are finite, the physical dimensions of the economy and the waste streams it produces cannot expand continuously. In contrast to more traditional economic theories, Ecological Economics is an economic discipline that gives a central position to the issue of scale. It aims to determine how large the physical dimensions of the economy should be, relative to the ecosystem that sustains it (Daly, 1992). This is challenging mainly because of the associated uncertainties intrinsically linked to modelling highly complex systems and feedback loops between society and its environment. As a result, current assessments with regards to the optimal extraction of geological resources, often ignore scale and the distribution of costs and benefits within and across generations. Geology as a discipline and the experience that geology has with uncertainties in geologically complex and poorly known systems, is a useful basis to reveal the intimate links between the Earth’s natural resources and societal development. 4. Geology as the correct starting point Traditional economic assessments are not designed for looking deep into the future, for example to compare an immediate gain of an activity (e.g. coal mining) with indirect costs to society that it may have in the future (e.g. long-term consequences of subsidence). Being flexible in handling time is one of the first elements to master for students in geology. Equally well embedded and relevant is understanding how depth (as in distance) can change the nature of a problem. Two aspects are linked when considering depth. With depth, the amount of data and degree of understanding dramatically decreases, but also the degree to which the subsurface can be engineered to our needs. Already from a depth of several tens of meters, direct observations of the subsurface require drillings, but these are nearly point observations. Geophysical techniques may offer 2D or 3D visualisations, but are based on indirect data. With increasing depth, the effort for obtaining information increases rapidly. Hence, data generally becomes more spares as depth increases. This is essential to understand resources and reserves, but also development of the subsurface, because the challenge of realising deep applications comes from two sides: information decreases, but also the degree to which we can adjust the subsurface to our needs through engineering diminishes. The subsurface will have to be largely accepted as is. Nevertheless, computing power has allowed to shift from qualitative understanding of the subsurface, towards quantitative verification or justification. Binding geology into economic evaluations has been done successfully, but mainly at project level to simulate or optimise project decisions of investors. The step towards interdisciplinary and system wide evaluations needed to analyse the complex interaction of societies and their environment is certainly unprecedented. 5. Theory to practice: Sustainable choices in the Campine Basin To demonstrate an Ecological Economics approach to a practical case, the setting of the Campine Basin is chosen. As a geological unit, the Campine Basin can be used for storage of nuclear waste or CO2 geological storage, it is being developed for deep hydrothermal energy production, and is in use for the seasonal storage of natural gas. Historically it has been mined for coal, with significant reserves remaining for potential future valorisation, and has potential for gas or oil shale. It is also an area with active groundwater production. The Campine Basin is certainly small compared to the potential subsurface demand, while large parts have only moderately been explored. This makes it a-priori challenging to estimate the impact radius of different subsurface activities, or their environmental economic and long-term effects. For this area, the construction of a model will be attempted using economic and semi-analytical geological techniques to integrate the economy, geology, and ecology into one realistic system. The model will integrate over a decade of experience with simulating and forecasting highly uncertain systems. This interdisciplinary model for the Campine Basin then becomes the starting point for the actual analysis, which will ultimately allow to determine the optimal scale and ranking at which subsurface activities are developed. As such, geology will provide the expertise to handle system complexity in such a way that the development can be optimised from a societal point of view. This deeply engraining of geology into other disciplines is fundamental and opens completely new paths to scientifically based future policy. It is referred to as Geological Economics.

1. Introduction The EU has set ambitious goals on the reduction of CO2 emissions into the atmosphere for limiting the effects of global warming. And while renewable alternatives are available in some cases, long-term storage of large quantities of produced CO2 seems inevitable. Because the process of capturing, transporting and injecting CO2 into a reservoir (CO2 capture and storage, CCS) is costly and current revenues from the EU emission trading system (ETS) are insufficient to cover the expenses, the commercial deployment of CCS is delayed in Europe. A potential business case for CO2 geological storage (CGS) is CO2-enhanced oil recovery (CO2-EOR), where CO2 is used to drive out 5-15% additional oil after the application of primary and secondary recovery techniques. Within Europe, the North Sea is the main oil province with a high potential for CO2-EOR. Earlier studies have concluded that off-shore CO2-EOR projects are a viable business case, but no investments have been made yet. Moreover, adversaries of this technology often point out that CO2-EOR is not a climatefriendly solution because its goal is to increase and lock-in fossil fuel production. 2. Economic and environmental analysis To investigate the potential of CO2-EOR, an integrated geological, techno-economic and environmental analysis is made of a potential candidate for EOR in the North Sea: the Buzzard oil field (Roefs et al., in press). A techno-economic spreadsheet calculation is made for different injection scenarios. The net present value (NPV) is calculated as the discounted cash flows over time. A full-sized coal-fired power plant is assumed, producing about 4 MtCO2/y, of which the Buzzard field can accept 2.9 Mt/y for EOR. A second injection location in an aquifer is also assumed. The market scenario is chosen at an oil price of 50 €/bbl, and an ETS price at 5 €/t. In parallel, a life cycle assessment (LCA) is conducted to compare the environmental impact, considering emissions from the additional construction and operation of the capture plant and EOR operation.. Results are expressed as the global warming potential (GWP). Four scenarios are considered: CO2 capture and storage in an offshore aquifer; CO2-EOR in the Buzzard field followed by emission into the atmosphere; CO2-EOR and parallel aquifer storage; and CO2-EOR and parallel aquifer storage, with a continuation of storage in the Buzzard field after the cease of oil production. For the first time such an integrated economic and environmental analysis is made comparing CGS and EOR. Results show that the scenario with only CGS has the lowest GWP (reference level for the other scenarios), but the NPV is negative (-800 M€) and thus does not provide a viable investment option. The scenario with only EOR has the highest NPV (>500 M€), but also has the highest GWP, 38% higher than the storage-only scenario. The results for the third and fourth scenario are very similar, with a GWP of 11% more than the storage-only scenario,and an NPV of 207 and 220 M€ respectively. This shows that CO2-EOR can be a viable investment that, when combined with CO2 storage, only has a minor additional environmental impact over a storage-only project. EOR can thus also serve as an enabler for CGS, with a widespread storage deployment when the necessary infrastructure is in place. It is also beneficial to use the depleted oil field for storage (fourth scenario) over aquifer storage (third scenario), because the necessary infrastructure is already present. From a sustainability perspective this also makes sense, as it allows for a more efficient use of geological resources. 3. Geo-economic simulation The analysis shows that even at low oil and CO2 prices, EOR projects can be viable. Since no projects are (soon becoming) operational, other factors are influencing the economic viability too. A more advanced geo-economic analysis is therefore performed with the PSS simulator from the point of view of an investor for the Buzzard field. In a more realistic approach, investment decisions are simulated, considering limited foresight generated by market and reservoir uncertainty. Results show that an increased hurdle rate results in a lower chance of a negative project value (Fig. 1, Welkenhuysen et al., subm.). A hurdle rate of 12% removes all project risk, but also eliminates potentially viable projects. At an oil price of 50 €/bbl, the threshold for EOR investment occurs at 0 €/tCO2 (green dotted line; excluding capture cost). The discrepancy with the cost for capture is too much to be covered by the current CO2 market price of around 15 €/t (June 2018). CO2-EOR with or without CGS in the North Sea therefore does not come forward as commercially viable from this study, where, in comparison to state-of-the-art assessments, more realistic economic and geological uncertainties are used. It does, however, have strategic and environmental benefits compared to a situation where oil is imported into the EU. In that context, incentives to reduce the cost and/or risk could be justified. Future research will focus on the establishment of contractual agreements between the parties, including uncertainty in the environmental analysis, and the scarcity cost of storage capacity as a limited commodity will be taken into account.

Among the most outstanding Cenozoic marine Fossil-Lagerstätten worldwide, the Peruvian Pisco Formation is renowned for its exceptional preservation and abundance of fossil vertebrates, especially cetaceans. We present an updated overview and interpretation of taphonomic data gathered during fifteen field campaigns (2006-2019) on 890 fossil marine vertebrates from the Miocene strata of the Pisco Formation exposed in the Ica Desert. In order to assess the factors that led to the formation of such an exceptional Konzentrat- and Konservat-Lagerstätte, we made observations that range from the taxonomic distribution, articulation, completeness, disposition and orientation of skeletons, to the presence of bite marks, associations with shark teeth and macro-invertebrates, bone and soft tissue (i.e., baleen) preservation, and the formation of attendant carbonate concretions and sedimentary structures. We propose that the exceptional preservation and abundance of the Pisco Formation specimens cannot be ascribed to a single cause, but rather to the interplay of favorable palaeoenvironmental factors and suitable timing of mineralizing processes, such as: i) low concentration of dissolved oxygen at the seafloor; ii) the early onset of mineralization processes; iii) rapid burial of the carcasses; and iv) original biological richness in the southeastern Pacific. Our observations provide a comprehensive overview of the taphonomic characteristics of one of the most significant fossiliferous deposits of South America and lead to the elaboration of a complex scenario for the preservation of its marine vertebrates that might serve as a reference for explaining the formation of other marine vertebrate Fossil-Lagerstätten worldwide.