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We use a system dynamics model to analyse the cycle of production of a nonrenewable natural resource, with a specific interest in crude oil. This subject has been empirically studied for a long time. However, modelling studies able to correlate the peaking with the parameters of the system have been very rare, and only recently proposed. In the present paper, we examine the timing of the peaking mainly as a function of the energy return for energy invested (EROI). The model provides approximate formulas for evaluating the peak time and “rules of thumb” that are useful for understanding the peaking phenomenon in the exploitation of natural resources. It shows that the peaking of the production curve occurs at a time that is inversely proportional to the EROI of the process at the start of the cycle.

Limiting climate heating while meeting basic needs of all necessitates eliminating fossil carbon emissions. This paper discusses the dynamics of mobilizing materials required for large-scale deployment of renewable energy, which entail: 1) availability of resources in the environment and technosphere; 2) accessibility, which depends on resource quality and available technologies; 3) processability, which depends on energy availability, processing capacity, and environmental impacts on planetary boundaries; and 4) operability, which depends on social acceptance and geopolitical agreements. Also, materials can be mobilized through four routes: 1) increasing primary production; 2) diverting existing primary production; 3) repurposing existing in-use stocks; and 4) re-mining previous wastes and emissions. The interplay of these enabling factors determines the maximum possible rate of material mobilization and thus of the energy transition itself. This paper presents and discusses a framework to explore joint energy-material transformations, enabling to consider material aspects in transition modelling and guide technological developments.

The terrestrial water cycle links the soil and atmosphere moisture reservoirs through four fluxes: precipitation, evaporation, runoff, and atmospheric moisture convergence (net import of water vapor to balance runoff). Each of these processes is essential for human and ecosystem well-being. Predicting how the water cycle responds to changes in vegetation cover remains a challenge. Recently, changes in plant transpiration across the Amazon basin were shown to be associated disproportionately with changes in rainfall, suggesting that even small declines in transpiration (e.g., from deforestation) would lead to much larger declines in rainfall. Here, constraining these results by the law of mass conservation, we show that in a sufficiently wet atmosphere, forest transpiration can control atmospheric moisture convergence such that increased transpiration enhances atmospheric moisture import and resulting water yield. Conversely, in a sufficiently dry atmosphere increased transpiration reduces atmospheric moisture convergence and water yield. This previously unrecognized dichotomy can explain the otherwise mixed observations of how water yield responds to re-greening, as we illustrate with examples from China's Loess Plateau. Our analysis indicates that any additional precipitation recycling by additional vegetation increases precipitation but decreases local water yield and steady-state runoff. Therefore, in the drier regions and early stages of ecological restoration, the role of vegetation can be confined to precipitation recycling, while once a wetter stage is achieved, additional vegetation enhances atmospheric moisture convergence and water yield. Evaluating the transition between regimes, and recognizing the potential of vegetation for enhancing moisture convergence, are crucial for characterizing the consequences of deforestation and for motivating and guiding ecological restoration., Comment: 39 pages, 12 figures, 5 tables

Development of the Italian clinical practice guidelines on bariatric and metabolic surgery, as well as design and methodological aspects. Background: Obesity and its complications are a growing problem in many countries. Italian Society of Bariatric and Metabolic Surgery for Obesity (Società Italiana di Chirurgia dell’Obesità e delle Malattie Metaboliche—SICOB) developed the first Italian guidelines for the treatment of obesity. Methods: The creation of SICOB Guidelines is based on an extended work made by a panel of 24 members and a coordinator. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) methodology has been used to decide the aims, reference population, and target health professionals. Clinical questions have been created using the PICO (Patient, Intervention, Comparison, Outcome) conceptual framework. The definition of questions used the two-step web-based Delphi method, made by repeated rounds of questionnaires and a consensus opinion from the panel. Results: The panel proposed 37 questions. A consensus was immediately reached for 33 (89.2%), with 31 approved, two rejected and three which did not reach an immediate consensus. The further discussion allowed a consensus with one approved and two rejected. Conclusions: The areas covered by the clinical questions included indications of metabolic/bariatric surgery, types of surgery, and surgical management. The choice of a surgical or a non-surgical approach has been debated for the determination of the therapeutic strategy and the correct indications.

Overexploitation is the phenomenon that occurs when an economic resource is exploited at a rate faster than it can be regenerated by natural processes. It affects both renewable and non-renewable resources. Overexploitation, and the related effect of “overshoot,” may lead to the complete destruction of the resource being exploited and the collapse of the economic system exploiting it. Nevertheless, overexploitation is common in the economy, although its mechanisms and consequences are often unknown to the public and to decision makers. The present paper aims at providing a tool to disseminate the concept of overexploitation by simulating it using the technique of “gamification.” We created a simple boardgame based on a system dynamics model that maintains the basic elements that generate overexploitation. The game is called the “Moby Dick Game” and it is inspired by the whaling cycle of the 19th century. Other versions of the game can be used to simulate, for instance, oil extraction. The game was tested on several groups of students and interested people with different backgrounds. The players usually reported to have learned for the first time the mechanisms that lead to overexploitation and collapse.

The Energy Return on Energy Invested, EROEI, is known as an important parameter for evaluating the efficiency of energy-producing technologies. In this paper we examine the concept of EROEI from a general viewpoint, giving insights on a wider range of applications. In general, natural resources can be seen as energy stocks characterized by a “potential” that can be exploited by creating intermediate stocks. This transformation is typical of dissipative systems and for the first time we found that Lotka-Volterra model, usually confined to the study of biology of populations, can represent a powerful tool to estimate EROEI for some such systems, providing an understanding of the reason for the overexploitation phenomenon and, in some cases, the collapse of the exploiting system.

20 years ago, in 1998, Scientific American published a paper by Colin J. Campbell and Jean H. Laherrere titled “The End of Cheap Oil” [1], starting a debate on oil depletion continuing to the present day. It was the return of a viewpoint on oil depletion which had been proposed more than 40 years before by Marion King Hubbert [2]⁠ and, in later years, largely forgotten. In their paper, Campbell and Laherrere updated Hubbert’s model with new reserve estimates and proposed that the world’s crude oil production would peak around 2004–2005, and then start an irreversible decline. Shortly afterward, Colin Campbell proposed the term “peak oil” for the highest global oil production level. The term was to become popular over the following decade, generating a true movement of ideas sometimes called the “peak oil movement.” Today, these predictions turn out to have been only partially correct, mainly because the role of “non-conventional” oil was underestimated. The peak oil movement seems to have faded away, while the concept seems to have disappeared from the debate and to be commonly described has having been “wrong.” The present paper reviews the cycle of the peak oil movement, examining how the peak oil concept was understood with the public and the decision makers and what caused its diffusion and its demise, at least up to the present time.

In the present study, we compare energy transition scenarios from a new set of Integrated Assessment Models, the suite of MEDEAS models, based on a systems dynamic modelling approach, with scenarios from two already well know structurally and conceptually different Integrated Assessment Models, the Integrated MARKAL-EFOM System (TIMES) and the Long-range Energy Alternatives Planning system (LEAP). The investigation was carried out to cross-compare and benchmark the response of MEDEAS models with TIMES and LEAP in depicting the energy transition in two different countries, Austria and Bulgaria. The preliminary results show a good agreement across all the models in representing scenarios projecting historical trends, while a major discrepancy is detectable when the rate of implementation of renewable energy is forced to increase to achieve energy system decarbonization. The discrepancy is mainly traceable to the differences in the models’ conception and structures rather than in a real mismatch in representing the same scenarios. The present study is put forward as a guideline for validating new modelling approaches that link energy policy decision tools to the global biophysical and socioeconomic constraints.

We cannot count the fish in the sea, but it is possible to evaluate their number by looking at the yields of fishing. Today, we have good mathematical models that can be used for a quantitative estimate of the fish stocks. The origin of these models is the well-known “prey-predator” model developed by Alfred Lotka and Vito Volterra in the 1920s. In this chapter, the authors explain how this model works, the important information we can get from it and how it might be used to avoid fisheries collapse. A brief excursus on Vito Volterra life is given, a fascinating figure that has been the first source of inspiration for completing the book.

The relationship between humans and the sea and the sea’s creatures never was a peaceful one. Humans soon recognized that the oceans contain large amounts of exploitable resources, but they never really understood that the sea could be overexploited. The short-term vision of humans, focused on immediate profits, has damaged the marine diversity, sometimes beyond recovery. In this chapter, the authors describe some examples of the overexploitation of marine resources, starting with the massacre of the whales during the nineteenth century, then describing the destruction of the Atlantic cod of Newfoundland, and the collapse of the Caviar industry in the Capsian sea, both during the 1990s. And this strange war against the sea shows no sign of stopping.

Starting from a horror story by H.P. Lovecraft, we discuss the basic problems involved in the relationship of humankind and the sea. It turns out that our current prosperity has been created by the ruthless overexploitation of the sea, an action whose consequences we still have to face. This situation is analogous to how the inhabitants of the fictional city of Sarnath had to face the consequences of having exterminated its the previous dwellers. So, we need a different way to see the ecosystem, not as a resource but as part of our own life, in order to avoid the phenomenon of overexploitation and destroy not only the marine ecosystem, but humankind as well.

When and how did humans begin their relationship with the sea? Initially, they may have exploited the resources that the tides left available on beaches. But fishing soon became an important source of food in ancient times, especially with the development of a money-based economy that allowed fishermen to survive the unavoidable highs and lows of their trade. Fishing never became a remunerative job and, still today, fishermen are subject to the ancient “fisherman’s curse, ” the condition of being poor and the lowest rung of the social ladder. It is the result of the impossibility for fishermen to own the resources they exploit, unlike farmers, and hence the impossibility of accumulating capital. Nevertheless, fish was and is still indispensable for a healthy diet, rich in proteins, fatty oils, vitamin D, and other nutrients. Over ancient history, the problem of preserving the catch remained a basic limitation for the exploitation of marine resources. It was solved only in modern times with the development of canning and, later on, of the freezing techniques which allowed to preserve fresh fish for a much longer time and turning fishing from a craft to an major world industry.

The concept of “Blue Economy” is popular nowadays, with its promise of an abundance of resources that could be harvested from the sea not just in terms of food, but also as energy and minerals. This chapter describes these concepts and discusses their feasibility. It turns out that, in many cases, we are seeing a good deal of unjustified optimism. The main element of the blue economy, nowadays, is fish farming, or “aquaculture,” an industry that has been growing and raising many expectation. It is true that the sea could be exploited for food more than it is now, but we seriously risk to cause a global collapse of the whole marine ecosystem. Similar problems exist for other schemes: the sea can produce energy and minerals, but it is not going to be the bonanza that some people describe.

As a result of pollution, climate change, and overexploitation, we are witnessing a true “aquapocalypse” to use a term proposed by Daniel Pauly. The sea is being destroyed not just by overfishing, but as a result of climate change and of the poisoning of the sea used as a garbage bin for plastics and other kinds of waste. No matter how large the oceans are, their capability to withstand this damage is limited. Thus, the consequences are now visible, the Earth is taking is revenge: sea levels are rising, and the waters are throwing back plastic waste at the humans who produced them. To say nothing about the result of the pollution from heavy metals and pesticides that’s especially harmful to the creatures at the highest level of the food chain, that is humans. Can we stop this disaster? We need to hurry, but we are still on time.

Purpose In the age of internet memes spread around the world in very short time, it has been already proved that, in several cases, the mechanism of propagation is very similar to a flu infection. However, this model turns out to be invalid if the spreading is generated by the mass media (TV, radio and the like). This paper aims to explore for the first time this non-viral dynamic (“fallout model”). Design/methodology/approach Two different dynamic models were developed to explain the viral and the mass media-powered meme propagations, and both were tested using data from Google Trends. Findings Viral propagation is not the only mechanism of meme diffusion. Memes can also diffuse by a “fallout” model, in which the susceptible populations are affected by the meme messages almost simultaneously, as it happens in the physical world for a radioactive fallout or for other poisoning agents. Originality/value This study provides a method to determine whether a certain meme has been diffusing by means of its own viral power or has been “planted” as the result of a commercial advertising campaign or a government propaganda operation.

Nanoscience is a powerful tool to study matter at the scale where cooperative actions among atomic and molecular assemblies are effective, that is, in the nanometer range. Its application to technology is expected to bring new ways to improve our life by means of applications in fields such as environmental and materials science, pharmacy, and medicine. Given the progress in these areas, it is not too early to think in terms of large-scale production for nanotechnology-based products. At the same time, the consequence of a large-scale expansion of nanomanufacturing processes has not received sufficient attention so far, especially in terms of environmental impact. In this review, we highlight the issue of nanotechnology sustainability for biomedical applications. In particular, we discuss how (i) Life Cycle Assessment (LCA) models may help in guiding the choice of production processes; (ii) green chemistry can provide safe and environment friendly synthetic routes; and (iii) continuous flow methods may be implemented at large scale to give reproducible and highly controlled formulations for nanomedicine.

13 pages, 7 figures, 4 tables, 3 appendixes, supplementary data https://doi.org/10.1016/j.rser.2020.110105, This paper reviews different approaches to modelling the energy transition towards a zero carbon economy. It identifies a number of limitations in current approaches such as a lack of consideration of out-of-equilibrium situations (like an energy transition) and non-linear feedbacks. To tackle those issues, the new open source integrated assessment model pymedeas is introduced, which allows the exploration of the design and planning of appropriate strategies and policies for decarbonizing the energy sector at World and EU level. The main novelty of the new open-source model is that it addresses the energy transition by considering biophysical limits, availability of raw materials, and climate change impacts. This paper showcases the model capabilities through several simulation experiments to explore alternative pathways for the renewable transition. In the selected scenarios of this work, future shortage of fossil fuels is found to be the most influential factor of the simulations system evolution. Changes in efficiency and climate change damages are also important determinants influencing model outcomes, This work was supported by the European Union through the funding of the MEDEAS project under the Horizon 2020 research and innovation programme [grant agreement No 69128], With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

This chapter discusses how the models used to understand the future are built, what they are for, what they tell us, and what their limits are in warning us about collapses to come. It includes a section on why people tend to disbelieve models that predict collapse.

This chapter illustrates the central ideas of the book: strategies to prevent the typical cause of collapse: overexploitation, but also how to profit from collapses (hint: have someone else collapse, instead). Collapses are not a bug but a feature of the universe, so it is a good idea to plan in advance how to deal with them.

How and why collapses occur according to the science of complex systems. Includes a section on the networked structure of complex systems and a chapter featuring “Amelia the Amoeba,” Ugo Bardi’s unicellular assistant, whose descendants in a Petri dish experience all kinds of collapses.

This book started from a sentence written some two thousand years ago by the Roman philosopher Lucius Annaeus Seneca, “fortune is of sluggish growth, but the way to ruin is rapid.” Now that we have arrived to the end, we may return to Seneca and ask if we can still learn something from him and from the school of thought he belonged to, the Stoics.

Carbon capture and storage (CCS) for fossil-fuel power plants is perceived as a critical technology for climate mitigation. Nevertheless, limited installed capacity to date raises concerns about the ability of CCS to scale sufficiently. Conversely, scalable renewable electricity installations—solar and wind—are already deployed at scale and have demonstrated a rapid expansion potential. Here we show that power-sector CO2 emission reductions accomplished by investing in renewable technologies generally provide a better energetic return than CCS. We estimate the electrical energy return on energy invested ratio of CCS projects, accounting for their operational and infrastructural energy penalties, to range between 6.6:1 and 21.3:1 for 90% capture ratio and 85% capacity factor. These values compare unfavourably with dispatchable scalable renewable electricity with storage, which ranges from 9:1 to 30+:1 under realistic configurations. Therefore, renewables plus storage provide a more energetically effective approach to climate mitigation than constructing CCS fossil-fuel power stations. Carbon capture and storage can help reduce fossil-fuel power-plant emissions. Here the authors show that the energy return on input of thermal plants with carbon capture is in general lower than the energy return of most types of renewable energy even when combined with energy storage.

In this study, we report on the effects of three common transition metal ions, i.e., Ni2+, Cu2+ and Fe3+ on the electrodeposition of aluminum from a chloroaluminate ionic liquid, evaluated by means of electrochemical and morphological investigation. Aiming at the determination of the morphological and chemical effects on the aluminum coatings, variable amounts of ions were introduced into the electroplating bath. Thick (about 20 ?m) Al coatings were obtained by direct deposition (galvanostatic, 10 mA cm2, 2 h) on brass or carbon steel substrates (10 mm diameter disks), and their morphology was examined via rugosimetry, optical and electron microscopy. The chemical composition of the deposits was provided by EDX analysis. Nickel and iron resulted to have only moderate effects on the coatings properties, but copper affected the process even in tiny amounts being detected in the deposits for bath content as low as 10 ppm.

The vacuum/liquid interface of different ionic liquids obtained by dissolving bistriflimide salts of Ag, Al, Cu, Ni, and Zn in 1-butyl-3-methylimidazolium bistriflimide ([bmim][Tf2N]) was investigated under vacuum using AR-XPS and NEXAFS. The XPS spectra show chemical shifts of the nitrogen of the bistriflimide anion as a function of the metal type, indicating different strength of the coordination bonds. In silver bearing ILs, silver ions were found to be only weakly coordinated. On the contrary, Ni, Cu, Zn, and especially Al exhibit large chemical shifts attributable to strong interaction with the bistriflimide ions. The outermost surface was enriched with or depleted of metal ions as a function of the nature of the metals. Nickel and zinc tend to slightly concentrate at the surface while copper, silver, and especially aluminum are depleted at the surface. We also observed that the aliphatic alkyl chains of the cations tend to protrude outside the surface in all systems studied. However, the presence of metals generally increases the amount of bistriflimide at the vacuum/liquid interface. (C) 2015 Elsevier B.V. All rights reserved.

MEDEAS (Modelling the Energy Development under Environmental And Socioeconomic constraint) World is a new global-aggregated energy-economy-environmental model, which runs from 1995 to 2050. In this work, we tested the MEDEAS world model to reproduce the IPCC (International Panel on Climate Change) GHG (Green House Gases) emission pathways consistent with 2 {\deg}C Global Warming. We achieved parameter optimizations of the MEDEAS model related to different scenarios until 2050. We chose to provide a sensitivity analysis on the parameters that directly influence the emission curves focusing on the annual growth of the RES (Renewable Energy Sources), GDP (Gross Domestic Product) and annual population growth. From such an analysis, it has been possible to infer the large impact of GDP on the emission scenarios., Comment: Submitted to puntOorg International Journal on 30/07/2019 (special issue Systemic Approaches)

We report the results of a “theatrical” approach designed to enliven the teaching of sustainability for students. It is based on a theater piece that can be performed by the teachers or proposed to students to perform themselves. It should be coupled with a more formal teaching of the basic concepts of sustainability as part of an introductory level university course or for high school students. Our experience shows that this approach can enliven the subject matter and interest students at various levels, thereby providing a connection with more advanced modeling on sustainability at the research level in universities and research institutes with the perception of people who are not researchers. Considering that the work on sustainability being performed in university campuses is often perceived as abstract and theoretical, rather than having practical applications, this approach is also a way to connect the general public with the work being done in universities and research institutes.

Waste management is becoming an urgent element of sustainability where university campuses can provide a substantial contribution in: (1) offering the competence necessary to optimize waste management and (2) giving the example in how to correctly manage waste in a relatively large entity such as in a university campus. In this area, the University of Florence engaged, together with the National Consortium on the Science and Technology of Materials (INSTM), in a project: ECOMAPS financed by the Tuscan Regional Government. ECOMAPS has the aim of developing a web-based platform which is addressed to everyone but in particular to industries to optimize waste disposal. Thus, the customer, who needs to dispose of waste, will be directly connected with the appropriate facility. The novelty of ECOMAPS lies in the geolocation system which allows the users to easily find the closest facility for waste disposal. This web page will be connected to an already existent blog Ecomaps news where the user not only can get the information related to waste disposal but also the technical support. The project is at present focused on industrial waste, but it can be extended to urban waste and we plan to create a model platform for the management of on-campus waste.

This paper reports the results of three years of work at the University of Florence dedicated to waste management and other sustainability-related activities. The rationale that guided this effort was to use the prestige of the University to disseminate knowledge about good practices of waste management with the local society. The results presented here are still preliminary, but we believe they are promising and worth of further exploration.

The Global Carbon Budget is the cumulative carbon emissions that human activities can generate while limiting the global temperature increase to less than 2°C. On this basis, most countries ratified the Paris Agreement 2015, pledging to reduce national emissions and the impacts of climate change. The European Union has planned to reduce emissions by 80% of their 1990 value by 2050 but such a target needs to be coupled with a further constraint on the cumulative greenhouse gases released along the path to 2050. The aim and the novelty of this study are to propose, for the first time, a carbon budget for the European Union, which represents the most significant physical characteristic to assess the feasibility of current EU-28 greenhouse gas reduction objectives under the goals of the 2015 Paris treaty

The Paris Agreement, ratified in 2015, pledged to reduce greenhouse gas emissions within a Global Carbon Budget that limits the global temperature increase to less than 2 °C. With the Roadmap 2050 mitigation measures, the European Union has a target to reduce emissions by 80% of their 1990 value by 2050 but without giving an estimation or a maximum ceiling for the total amount of cumulative greenhouse gases emissions over that period. Thus, the impact of the EU regulations on global warming remains unestimated. The aim and the novelty of this study are to develop a set of potential European emissions trajectories, within the Global Carbon Budget and at the same time satisfying the Roadmap 2050 goals. The result of the study highlights the urgency to reinforce mitigation measures for Europe as soon as possible because any delay in policy implementation risks the Roadmap 2050 mitigation package being insufficient to achieve the objectives of the Paris treaty, This work was supported by the MEDEAS project, funded by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 691287. The opinion expressed in the present work are those of the authors’ only and are not to be attributed to any organisation of the European Union