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Fossile Kapitalanlagen entlang der gesamten Wertschöpfungskette – von Reserven bis zu Infrastruktur und Unternehmenswerten – werden durch die Transformation des Energiesystems in den nächsten Jahrzehnten massiv an Wert verlieren, also zu „Stranded Assets“ werden. Die Erfassung dieser Verluste hilft, Einzelinteressen in der Klimapolitik besser zu verstehen.

Does climate change adaptation require that investments are designed to be more robust? What about when climate change is more uncertain? What if the climate changes faster? This decision problem is difficult if the design of the investments is irreversible for their lifetime, for instance, in the construction industry. We study an irreversible design decision when the investment starts, combined with an irreversible option to abandon. The design determines the investment's robustness to sustain detrimental conditions. We find that for short-lived investments, optimal robustness decreases if the climate changes faster, and increases if uncertainty is higher. For long-lived investments, these effects reverse. This has implications for decision makers who plan infrastructure adaptation, for instance, that adverse climate change does not require more robust investments under the identified circumstances.

Recent years have seen a proliferation of studies that use archetype analysis to better understand and to foster transitions toward sustainability. This growing literature reveals a common methodological ground, as well as a variety of perspectives and practices. In this paper, we provide an historical overview of the roots of archetype analysis from ancient philosophy to recent sustainability science. We thereby derive core features of the archetype approach, which we frame by eight propositions. We then introduce the Special Feature, ���Archetype Analysis in Sustainability Research,��� which offers a consolidated understanding of the approach, a portfolio of methods, and quality criteria, as well as cutting-edge applications. By reflecting on the Special Feature���s empirical and methodological contributions, we hope that the showcased advances, exemplary applications, and conceptual clarifications will help to design future research that contributes to collaborative learning on archetypical patterns leading toward sustainability. The paper concludes with an outlook highlighting central directions for the next wave of archetype analyses.

Electricity from renewable sources often cannot be generated when and where it is needed. To deal with these temporal and spatial discrepancies, one frequently proposed approach is to expand storage capacities and transmission grids. It is often argued that the two technologies substitute each other, such that deploying one reduces the need for the other. Using a theoretical model, we show that storage capacities and transmission grids can also be complements if electricity system costs are minimized. We present the conditions that determine the kind of interdependence at specific storage locations: the characteristics of transmission congestion, i.e., during peak or off-peak and uni- or bidirectional as well as the alignment of marginal generation costs between adjacent regions. By applying our theoretical insights to Italian power system data, we obtain empirical evidence that storage and transmission can act as either substitutes or complements. Planners of long-lasting and costly infrastructure can use the results to avoid design errors such as a misplacement of storage within the system.

Games are increasingly proposed as an innovative way to convey scientific insights on the climate-economic system to students, non-experts, and the wider public. Yet, it is not clear if games can meet such expectations. We present quantitative evidence on the effectiveness of a simulation game for communicating and teaching international climate politics. We use a sample of over 200 students from Germany playing the simulation game KEEP COOL. We combine pre- and postgame surveys on climate politics with data on individual in-game decisions. Our key findings are that gaming increases the sense of personal responsibility, the confidence in politics for climate change mitigation, and makes more optimistic about international cooperation in climate politics. Furthermore, players that do cooperate less in the game become more optimistic about international cooperation but less confident about politics. These results are relevant for the design of future games, showing that effective climate games do not require climate-friendly in-game behavior as a winning condition. We conclude that simulation games can facilitate experiential learning about the difficulties of international climate politics and thereby complement both conventional communication and teaching methods.

The implementation of theoretically designed low carbon energy transitions provided by scientific policy advice proves to be challenging in practice. For the case of Germany prominent rhetoric frontlines separate proponents of centralized and decentralized solutions for decarbonizing its electricity infrastructure. This paper investigates whether the claim that incumbent actors favor centralized and challengers decentralized solutions finds supporting evidence on a small sample of practitioners from different fields of the German electricity system. It further aims to identify qualitative infrastructure scenarios for its long-term future based on the practitioners’ mental models of system effects. We find empirical evidence for the postulated claim; yet there are no clear-cut camps. Disagreements across elicited mental models of practitioners from the same fields render the identification of internally consistent scenarios impossible for the full sample. The largest possible subsamples lead to three related visions of a substantially transformed electricity system dominated by decentral, small and medium-scale solutions coexisting with some centralized, large-scale infrastructures. The strong heterogeneity in preferences and mental models we uncover leads us to conclude that transparent and participatory public discourse on underlying worldviews, norms and values is paramount for accelerating institutional reform paving the way for energy transitions in Germany and globally.

Climate policies can target either the demand or the supply of fossil fuels. While demand-side policies have been analyzed in the literature and applied in policy-making, supply-side policies, e.g. deposit policies, are a promising option and a recent research focus. In this paper we study deposit markets for two fuels that differ in emission intensity. We find that, with strategic action on the deposit markets, deposit policies are inefficient due to price manipulations within and between both deposit markets. Regarding the political economy of deposit policies, they generate more welfare for all countries if applied to both fuels as opposed to one or none. Further, for perfectly segmented fuel markets, importing countries do not purchase deposits of a sufficiently clean fuel. If fuels are substitutes and strongly differ in emission intensity, countries do not buy deposits of a relatively clean fuel. Finally, deposit markets can induce countries selling deposits to choose a cleaner fuel mix.

This article studies adaptation of institutional arrangements for water regulation to climate change. Power plants occasionally need to curtail production during heat waves, causing economic losses and putting power quality at risk. To avoid exacerbation of this problem due to climate change, the regulation of heat emissions from power plants may require adaptation. The analysis abstracts a mathematical model from a case study of the German Rhine catchment. The model compares three options for regulation with an analysis of transaction costs, and balances them with costs from environmental externalities. First, long-term and site-specific temperature caps lead to the comparatively lowest sum of social transaction and production costs if heat waves only increase in intensity. Second, a dynamic heat load plan performs better if heat waves only increase in frequency. Third, if both intensity and frequency of heat waves increase substantially, a specific contract between the environmental regulator and electricity producers (the minimum power plant concept) performs comparatively best. The article highlights economies of scale in transaction costs, and shows how institutional adaptation can depend on the speed of climate change.

When multiple power plants are curtailed at the same time and in the same region, electricity system costs rise. If transmission lines are congested, these costs might be amplified and spatially more concentrated, because there are less spatial spill-overs. We study how such costs and their distribution depend on the market design (nodal pricing or uniform pricing). We extend the literature on curtailment by considering space and market design, and the literature on market design by considering curtailment. We expose a DC load-flow model for Germany to severe correlated curtailment scenarios. We find that additional costs are moderate. For the simulated week, curtailment of 9.3% non-renewable capacity reduces welfare by 2.7% (uniform pricing). With nodal pricing, welfare loss can be reduced by 1.5%. Distributional differences are multiple times larger. For nodal pricing, producer surplus rises more, and costs are spatially more concentrated at the curtailed power plants. Consumer surplus becomes lower. The difference is unlikely to justify changes of the current market design. If also wind or photovoltaic feed-in is unavailable, economic impacts can decrease or increase, but remain in the same order of magnitude. The spatial electricity system structure matters more than the volume of curtailment.

We extend the theory of peak-load pricing by considering that the production with different technologies can be adjusted within their capacity at different speeds. In the established analysis, all production decisions can be made after the random variables realize. In our setting, in contrast, some decisions are made before, others after. This is important, e.g., when increasing capacities of renewables are integrated in electricity systems worldwide. We consider fixed load and three types of capacities: partially dispatchable capacity (e.g., nuclear power-plants) needs to be scheduled ahead of actual production, non-dispatchable capacity (e.g., wind turbines) produces randomly, and highly-dispatchable capacity (e.g., gas turbines) can instantly adjust. If capacities differ in their dispatchability, some standard results of peak-load pricing break down. For example, less capacity types will be employed. Either a system with partially dispatchable technologies only, or a system dominated by non-dispatchable technologies and supplemented by highly-dispatchables occurs. Non- and highly dispatchable technologies can be substitutes or complements. The probability of outage does not rise if non-dispatchable capacity becomes cheaper. In a system with non-dispatchables, capacity decisions cannot be decentralized by conventional markets because cost recovery is not possible. Thus, the integration of renewable electricity generators requires alternative market designs.

This technical appendix of Eisenack and Mier (2019) presents the proofs and calculations (Section 1), and the extension to perfectly correlated generation units (Section 2). See also Eisenack and Mier (2018).

Against the backdrop of rural deprivation during the rapid urbanization of China since the end of the previous century, rural renewal has been regarded as a vital strategy for facilitating rural sustainability. Rural renewal in contemporary China involves activities that replan, consolidate, and redevelop the extant and idle rural construction land and then convert such land for alternative uses, including new rural settlement construction and rural industry development. However, given the regionally decentralized authoritarian (RDA) regime of China, i.e., a combination of political centralization and economic regional decentralization, the governance of rural renewal and its performance show great diversity. The objective of this study was to explore and elucidate the underlying patterns of sustainable rural renewal. Thus, from the social-ecological systems (SES) perspective, an archetype analysis was conducted based on primary data from 27 cases from the eastern, central, and western parts of China. In total, eight archetypical patterns were extracted, and the following three overarching implications were observed: (1) a governance system aligning with the attributes of rural land resources, the characteristics of actors, and the properties of interactions is essential for sustainable rural renewal; (2) decentralized or self-organized governance emerges to facilitate sustainable rural renewal; and (3) a long-term perspective of designing and enforcing rural renewal and distinctive land resource endowment contribute to rural sustainability. These findings may benefit China and other regions pursuing rural sustainability.

Policy advocates frequently call for unilateral action to promote international climate protection. It is still conventional wisdom that unilateral action does not pay off for individual countries due to free-riding incentives for other countries. Does this conclusion change if damage can be reduced by adaptation measures? This article considers adaptation as an explicit decision variable and frames unilateral action as Stackelberg game with two countries. The sequence of play is determined endogenously. We show that the Stackelberg leader reduces adaptation expenditures and emissions if the follower’s damage function has a specific convexity property where adaptation leads to strategic complements. Then, no country has an incentive to deviate from the sequence of play. Unilateral action in adaptation or in emissions leads to a strict Pareto improvement compared to the non-co-operative Nash solution. There are lower total emissions and less adaptation.

Unidad de excelencia María de Maeztu MdM-2015-0552 This article introduces the special issue on climate adaptation and institutions. Economic accounts of climate adaptation have stressed its collective action nature and the limitations of standard economic approaches to the matter. Governance accounts, on their part, have shown that adaptation does not always happen when it is expected. Against this background, institutional economics has the potential to shed light on those societal processes and collective mechanisms leading to and shaping adaptation (or the absence of it). The selection of articles contributing to this special issue shows that climate adaptation can indeed be explored successfully through institutional economics, and that doing so fits well within the institutional economics agenda. Some recommendations for future research are provided at the end.

Can we explain barriers to adaptation of collective action to changes in the natural environment? One reason for adaptation is the impacts of climate change. Ample case study evidence shows that such adaptation is rarely a smooth process. However, generalisable patterns of how and why barriers arise remain scarce. The study adopts a collective action perspective and the archetypes approach in a meta-analysis of 26 selected publications to explain how barriers arise in specific conditions. Focusing on adaptation of water governance in river basins, the study finds 21 reappearing patterns. Less well-established patterns relate to water property rights, hydrological standards, adaptation externalities, non-climatological uncertainty and vertical coordination. Results further show how barriers impede collective action in specific ways. The paper precisely introduces the archetypes approach, and shows that reported problems in adapting collective action under climate change arise from attributes of actors and pre-existing institutions rather than biophysical characteristics.

The transformation of critical infrastructure such as energy systems toward sustainability imposes a multitude of challenges that are social-technical in nature and require interdisciplinary collaboration. Resilience has received growing attention as a concept to bridge different scientific disciplines in research on energy systems, given their social, ecological, and technical elements. However, a resilience framework that is suitable for merging notions of resilience as a measurable property with notions of resilience as a social construction or an observatory scheme is still a desideratum. Against this backdrop, we present a cross-epistemic resilience (CER) framework for interdisciplinary research on energy and other social-ecological-technical systems. In particular, we introduce the distinction between positivist first-order and constructivist second-order observations and identify four modes of inquiry in resilience research. Our CER framework contributes to interdisciplinary resilience research by pointing out how assumedly incompatible perspectives are able to inform and constructively irritate each other and, hence, enhance the overall understanding of energy systems. The framework has been tested in a radically interdisciplinary research project. We draw on electricity systems as our prime example to illustrate the application of our arguments and concepts.

Thermoelectric power plants depend on cooling water drawn from water bodies. Low river run-off and/or high water temperatures limit a plant’s production capacity. This problem may intensify with climate change. To what extent do such capacity reductions affect electricity spot markets? Who bears the consequent costs? How is this influenced by climate change and a change in the electricity generation system? We quantify these effects by means of a bottom-up power generation system model. First, we simulate the German electricity spot market during the heat wave in 2006, and then conduct a sensitivity study that accounts for future climatic and technological conditions. We find an average price increase of 11%, which is even more pronounced during times of peak demand. Production costs accumulate to additional but moderate e15.9 m during the two week period. Due to the price increase producers gain from the heat wave and consumers disproportionately bear the costs. Carbon emissions increase during the heat wave. The price and cost effects are more pronounced and significantly increase if assumptions on heat-sensitive demand, hydro power capacity, net exports and capacity reductions are tightened. These are potential additional effects of climate change. Hence, if mitigation fails or is postponed globally, the impacts on the current energy system are very likely to rise. Increases in feed-in from renewable resources and demand-side management can counter the effects to a considerable degree. Countries with a shift to renewable energy supply can be expected to be much less susceptible to water scarcity than those with a high share of nuclear and coal-fired power plants.

We investigate whether global cooperation on emissions abatement can be improved if asymmetric countries agree to sign one out of several environmental agreements. The analysis is based on a two-stage game theoretical model. Conditions for stable coalitions and the resulting global emissions are determined. We allow for multiple coalitions with all countries being different, and analyze the effects in the cases of increasing marginal damages from emissions and of decreasing marginal benefits of emissions. We find that in the case of decreasing marginal benefits and constant marginal damages, admitting multiple coalitions increases the number of cooperating countries and reduces emissions (compared to the standard case with a single coalition). For increasing marginal damages and constant marginal benefits, however, multiple stable coalitions cannot coexist. If both damages and benefits are nonlinear, admitting multiple coalitions can decrease emissions. The paper thus contributes to the emerging discussion on the scope and limits of climate clubs.

The concept of barriers is increasingly used to describe the obstacles that hinder the planning and implementation of climate change adaptation. The growing literature on barriers to adaptation reveals not only commonly reported barriers, but also conflicting evidence, and few explanations of why barriers exist and change. There is thus a need for research that focuses on the interdependencies between barriers and considers the dynamic ways in which barriers develop and persist. Such research, which would be actor-centred and comparative, would help to explain barriers to adaptation and provide insights into how to overcome them.

International cooperation on climate change adaptation is regarded as one of the major avenues to reduce vulnerability in developing countries. Nevertheless, it remains unclear which design properties of international arrangements match with specific problems in local adaptation processes. This paper analyses conditions and institutional design options under which international cooperation can facilitate climate adaptation in urban areas in developing countries. We conduct a qualitative meta-analysis of empirical evidence from 23 cases. Using the archetype approach, we identify re-appearing barriers and change factors in urban squatter settlements and municipal public sectors in developing countries. We characterise five generic modes of international cooperation for climate adaptation based on UNFCCC documents, process observation, and literature review. Combining these analyses, we develop testable propositions that explain how specific design options of international arrangements can alleviate barriers and make use of change factors for urban adaptation in developing countries. We find, first, that international cooperation has the most potential to tackle adaptation barriers in squatter settlements if its institutional mechanisms support improvements of procedures and rights in localised state–society interactions. Second, national or regional centres of competence may foster endogenous dynamics in municipal public sectors. Third, national adaptation policies can enable and incentivise municipal adaptation. Fourth, flexible indicators of adaptation benefits are instruments to tailor international decision making and monitoring systems to local needs. We conclude that these insights, the archetypes approach, and a multi-level study design can be used to advance research on international cooperation, barriers, and success factors for climate change adaptation.

The paper considers an industry where production costs rise due to pollution, but where this effect can be partially off-set by investing in adaptation as a private good. The focus is not on external effects, but industries where economies of scale are introduced from adapting to pollution. The structure of the resulting oligopolistic market is endogenous, since the level of adaptation is chosen by the firms. The analysis of externalities usually disregards defensive or adaptation measures, with a few exceptions that point to considerable complications. The present debate on adaptation to climate change shows the importance of understanding defensive measures. I show that the market failure caused by economies of scale leads to production costs above the social optimum, i.e. to under-adapation. When pollution increases, adaptation only increases if demand is price inelastic. Otherwise, welfare loss from market failure decreases with pollution. The total welfare loss is only convex if demand is price inelastic and the influence of pollution on production costs is stronger than the influence of adaptation. Concave welfare loss has crucial implications for abatement policies.

In this guest editorial, we survey some of the main themes and issues in anthropogenic global warming. We emphasize the great potential of simulation/games as an educational strategy. The diversity of issues in climate change is matched by the variety of simulation/games. We then provide a summary of the main points of each of the eight articles, which together contain a wide range of perspectives on climate change, of types of simulation/gaming, of level of abstraction, and of method of implementation.

Climate change (CC) is an increasing societal concern for many countries around the world, and yet international negotiations continue to make slow progress. CC is an issue that is proving difficult to address using traditional approaches to information provision and education. This article reviews the development of climate and CC games and simulations in recent years as an alternative and novel way of addressing CC issues and communicating with decision makers. It gives an overview of published CC games and analyses a selection of 52 sophisticated CC games in detail. The results allow comparisons of the temporal development of climate games, actors involved in CC game development, game formats, and game subjects. Many climate games appeared around the time of the UN climate negotiations in Copenhagen in 2009, with an increasing number of commercial game developers entering the field. Role-play and management games dominate the scene, but we see a rapid increase in the number of online games or games with an online component. Both local and global mitigation issues are frequently addressed and as yet few games focus on adaptation to CC.

In Deutschland ist – wie in vielen Mitgliedstaaten der EU – Anpassung an den Klimawandel als eigenes Politikfeld mit einer nationalen Strategie, einem Masnahmenplan sowie fur die Umsetzung zustandigen Akteuren etabliert. Insbesondere bei physischen, raumwirksamen Masnahmen kommt dabei der kommunalen und regionalen Ebene eine masgebliche Rolle zu. Auf EU-Ebene kann die Umsetzung insbesondere durch einen geeigneten Forder- und Rechtsrahmen unterstutzt werden. Im Mittelpunkt des Kapitels stehen Klimaanpassungsstrategien auf den unterschiedlichen politischen Ebenen – von der EU bis zur Kommune –, Ansatze erfolgreicher Umsetzung und entsprechende Hemmnisse.

Carbon dioxide emissions correspond to fossil resource use. When considering this supply side of climate protection, crucial questions come to fore. It seems likely that owners of fossil resources would object to emission reductions. Moreover, policy instruments such as taxes may not be effective at all: it seems individually rational to leave no fossil resources unused. In this context, it can be expected that economic sectors will react strategically to climate policy, aiming at a re-distribution of rents. To address these questions, we investigate the effectiveness, efficiency, and resource rents for energy taxes, resource taxes, and quantity rationing of emissions. The analysis is based on a game theoretic growth model with explicit factor markets and policy instruments. Market equilibrium depends on a government that acts as a Stackelberg leader with a climate protection goal. We find that resource taxes and quantity rationing achieve this objective efficiently, energy taxation is only second-best. The use of quantity rationing to achieve climate protection generates substantial rents for resource owners.

This article reports and reflects on the design and use of the board game KEEP COOL on climate change. The game covers and integrates central biophysical, economic, and political aspects of the issue. By using a board game as common language between students and scientists from different scientific cultures, knowledge of different disciplines can be integrated and different views can be discussed. Thus, even complex issues such as the free-rider problem, trade-offs between adaptation to and mitigation of climate change, and path dependencies can be studied. KEEP COOL is the first game on climate change that is readily available from a commercial publisher. It has successfully been used in multiple settings, for example, as a tool for interdisciplinary research, public relations, public understanding of science, and, in particular, teaching. The experience with the game indicates that it can be effectively used in seminars with students to obtain a holistic picture of the issue and to lay out a common language for deeper reflections on climate change. This contribution also identifies some pitfalls and essential instruments for its adequate use for teaching.

The climate negotiations recognize that adequate and additional funds are needed to assist adaptation in developing countries. This article analyses whether a future 2% or any higher adaptation levy (AL) can achieve this, whether it causes – as it is a tax on the Clean Development Mechanism (CDM) – a significant excess burden, and how it alters the relation between adaptation financing and mitigation. While former studies have focused on single AL levels, this article determines the transfers from the CDM and the AL for a range of emission reduction targets and AL levels with a partial equilibrium model based on marginal abatement cost estimates for 2020. Revenues from a 2% AL are negligible and remain inadequate for ambitious emission reductions and an AL that maximizes transfers (e.g. US$15 billion for 30% reduction target). Revenues are mostly subtracted from CDM transfers, so little additional funds are raised (e.g. less than $2.4 billion for 30% reduction target). Adaptation financing increases dispr...

This paper identifies the literature that deals with adaptation to climate change in the transport sector. It presents a systematic review of the adaptations suggested in the literature. Although it is frequently claimed that this socially and economically important sector is particularly vulnerable to climate change, there is comparatively little research into its adaptation. The 63 sources we found are analysed following an action framework of adaptation. This distinguishes different adaptational functions and means of adaptation. By an open coding procedure, a total of 245 adaptations are found and classified. The paper shows a broad diversity of interdependent actors to be relevant—ranging from transportation providers to public and private actors and households. Crucial actors are hybrid in terms of being public or private. A substantial share of the identified adaptations follows a top-down adaptation policy pattern where a public or hybrid operator initiates action that affects private actors. Most of the exceptions from this pattern are technical or engineering measures. Identified adaptations mostly require institutional means, followed by technical means, and knowledge. Generally, knowledge on adapting transport to climate change is still in a stage of infancy. The existing literature either focuses on overly general adaptations, or on detailed technical measures. Further research is needed on the actual implementation of adaptation, and on more precise institutional instruments that fill the gap between too vague and too site-specific adaptations.

Conventional approaches to natural resource management are increasingly challenged by environmental problems that are embedded in highly complex systems with profound uncertainties. These so-called social-ecological systems (SESs) are characterized by strong links between the social and the ecological system and multiple interactions across spatial and temporal scales. New approaches are needed to manage those tightly coupled systems; however, basic understanding of their nonlinear behavior is still missing. Modeling is a traditional tool in natural resource management to study complex, dynamic systems. There is a long tradition of SES modeling, but the approach is now being more widely recognized in other fields, such as ecological and economic modeling, where issues such as nonlinear ecological dynamics and complex human decision making are receiving more attention. SES modeling is maturing as a discipline in its own right, incorporating ideas from other interdisciplinary fields such as resilience or complex systems research. In this paper, we provide an overview of the emergence and state of the art of this cross-cutting field. Our analysis reveals the substantial potential of SES models to address issues that are of utmost importance for managing complex human-environment relationships, such as: (i) the implications of ecological and social structure for resource management, (ii) uncertainty in natural and social systems and ways to address it, (iii) the role of coevolutionary processes in the dynamics of SESs, and (iv) the implications of microscale human decision making for sustainable resource management and conservation. The complexity of SESs and the lack of a common analytical framework, however, also pose significant challenges for this emerging field. There are clear research needs with respect to: (i) approaches that go beyond rather simple specifications of human decision making, (ii) development of coping strategies to deal with (irreducible) uncertainties, (iii) more explicit modeling of feedbacks between the social and ecological systems, and (iv) a conceptual and methodological framework for analyzing and modeling SESs. We provide ideas for tackling some of these challenges and indicate potential key focal areas for SES modeling in the future.

Developing generalized theories about adaptation to climate change requires common concepts to map different adaptation situations. The paper aims to contribute to this endeavor by presenting a novel framework that conceptualizes adaptations to climate change as actions. The framework is intended to systematically analyze the actor relations involved in adaptations and the barriers to their implementation. By combining established scientific action theories with terminology from the Intergovernmental Panel on Climate Change (IPCC) in an innovative way, it can be used to clarify the notion of adaptation used in adaptation assessments. The framework’s potential is illustrated by a case study on cooling water management in the river Rhine catchment and by the elucidation of some prominent concepts in adaptation research. We show that by framing adaptations as actions, the purpose of adaptations and how they tend to connect up in means-ends-chains becomes crucial. Actors can take different functional roles as exposure unit, operator and receptor of adaptation. A mismatch of these roles can lead to barriers to adaptation, of which we deduce four types: complex actor relations, missing operators, missing means and unemployed means. The case study yields a complex bundle of adaptations, and shows that the potential barriers involved are quite diverse. There is thus no blueprint solution. Although we identify entry points for adaptation, the analysis leads to a skeptical conclusion for adapting cooling water management in the whole Rhine catchment.

In this paper we present an algorithm that deals with trade interactions within a multi-region model. In contrast to traditional approaches this algorithm is able to handle spillover externalities. We focus on technological spillovers which are due to capital trade. The algorithm of finding a pareto-optimal solution in an intertemporal framework is embedded in a decomposed optimization process. The paper analyzes convergence and equilibrium properties of this algorithm. In the final part of the paper, we apply the algorithm to investigate possible impacts of technological spillovers. While benefits of technological spillovers are significant for the capital-importing region, benefits for the capital-exporting region depend on the type of regional disparities and the resulting specialization and terms-of-trade effects.

To determine the influence of the biosphere on weathering we use a dynamic model of the global carbon cycle. It takes into account the most important processes for the long-term evolution of the Earth. The model is solved under a slowly changing environment of increasing solar luminosity and volcanic activity and continental area. By comparing the model results for the global average temperature with data derived from δ 18 O values from cherts it is possible to quantify the biogenic enhancement factor of weathering. For this purpose a newly developed inverse viability method is applied, which allows for calculating the range of possible biogenic enhancement factors consistent with the data. We find that in the Precambrian the weathering was 5.4 times lower than in the Phanerozoic era. This supports the hypothesis that the Cambrian explosion was caused by a positive feedback between the spread of biosphere, increased silicate weathering, and a consequent cooling of the climate.

Strongly correlated and spatially concentrated curtailment of power plants strongly affects the electricity market. Such curtailment is observed during heat waves in middle Europe, for example. First, curtailed power plants need to be substituted by more expensive ones. Second, additional congestion of the electricity grid may constrain substitution. These consequences and their spatial incidence have yet not been thoroughly assessed at the level of a national electricity system. Does congestion excessively amplifes curtailment costs? Do costs remain localized? How does the cost incidence depend on the market design? We employ a calibrated DC load flow model of the German electricity system that simulates an energy-only market followed by redispatch, as well as nodal prices, for a representative week and renewable feed-in scenarios. We find that spatially concentrated curtailment by 10% of Germany's installed non-renewable generation capacity leads to a 3% welfare loss of the market value, but that loss is not driven by congestion. The electricity price rises by 14% in average, and up to 17% in peak load hours. Consumers bear the burden of curtailment, whereas producer gain in the aggregate. Effects considerably spill over to other regions. While consumers in Southern Germany always lose, consumers in Eastern and Western Germany may gain welfare. Nodal pricing reduces loss by up to 1.5%, and shifts a larger burden to consumers and to Southern Germany. The aggregated economic effects of curtailment are manageable in Germany, but its distributional effects are multiple times larger.

Capital accumulation has been a major issue in fisheries economics over the last two decades, whereby the interaction of the fish and capital stocks were of particular interest. Because bio-economic systems are intrinsically complex, previous efforts in this field have relied on a variety of simplifying assumptions. The model presented here relaxes some of these simplifications. Problems of tractability are surmounted by using the methodology of qualitative differential equations (QDE). The theory of QDEs takes into account that scientific knowledge about particular fisheries is usually limited, and facilitates an analysis of the global dynamics of systems with more than two ordinary differential equations. The model is able to trace the evolution of capital and fish stock in good agreement with observed patterns, and shows that over-capitalization is unavoidable in unregulated fisheries., Comment: 24 pages, 6 figures