Carlo Jaeger

• Global Climate Forum

Agent-based models (ABMs) offer a powerful framework for understanding complex systems. However, their computational demands often become a significant barrier as the number of agents and complexity of the simulation increase. Traditional ABM platforms often struggle to fully exploit modern computing resources, hindering the development of large-sc...

Global warming is exacerbating flood hazards, making the robustness of flood risk management a critical issue. Without considering future scenarios, flood risk analysis built only on historical knowledge may not adequately address the coming challenges posed by climate change. A comprehensive risk analysis framework based on both historical inundat...

Strategies of community‐based disaster risk reduction have been advocated for more than 2 decades. However, we still lack in‐depth quantitative assessments of the effectiveness of such strategies. Our research is based on a national experiment in this domain: the “Comprehensive Disaster Reduction Demonstration Community” project, a governmental pro...

Klaus Hasselmann has earned the 2021 Nobel Prize in physics for his breakthroughs in analysing the climate system as a complex physical system. Since decades, as a leading climate scientist he is aware of the need for creative cooperation between climate scientists and researchers from other fields, especially economics. To facilitate such cooperat...

Policy makers dealing with complex environmental problems need knowledge from environmental science as well as from the social sciences to back up their decisions. Integrated Assessment (IA) research aims at providing useful overviews of relevant problems and elements of possible solutions for this purpose. In this context ULYSSES - short for Urban...

This timely and insightful collection of essays written by economists from a range of academic and policy institutes explores the subject of public investment through two avenues. The first examines public investment trends and needs in Europe, addressing the initiatives taken by European governments to tackle the COVID-19 recession and to rebuild...

Objectives To explore changes in quality of life and perceived productivity, focusing on the effects of working from home during the first COVID-19 50-day mitigation period in Austria. Methods We conducted an Austrian-representative online survey ( N = 1010) of self-reported life- and work-related changes during the first COVID-19 50-day mitigatio...

Recurrent outbreaks of the coronavirus disease 2019 (COVID-19) have occurred in many countries around the world. We developed a twofold framework in this study, which is composed by one novel descriptive model to depict the recurrent global outbreaks of COVID-19 and one dynamic model to understand the intrinsic mechanisms of recurrent outbreaks. We...

COVID-19 has revealed that science needs to learn how to better deal with the irreducible uncertainty that comes with global systemic risks as well as with the social responsibility of science towards the public good. Further developing the epistemological principles of new theories and experimental practices, alternative investigative pathways and...

Background: With the coronavirus disease 2019 (COVID-19) pandemic surging and new mutations evolving, trust in vaccines is essential. Methods: We explored correlates of vaccine hesitancy, considering political believes and psychosocial concepts, conducting a non-probability quota-sampled online survey with 1007 Austrians. Results: We identified s...

We would like to extend on the article by Alley et al [...]

The European Green Deal aims at climate neutrality for Europe by 2050, implying a significant acceleration of emission reductions. To gain the necessary support, it needs to reduce regional and social inequalities in Europe. We present objectives in terms of jobs, growth and price stability to complement the emission reduction targets and sketch a...

Reaching the Sustainable Development Goals requires a fundamental socio-economic transformation accompanied by substantial investment in low-carbon infrastructure. Such a sustainability transition represents a non-marginal change, driven by behavioral factors and systemic interactions. However, typical economic models used to assess a sustainabilit...

COVID-19 has been a stress test for our globalized society. The results, thus far, have not been encouraging. While responses and outcomes have varied across regions and countries, the pandemic has also revealed severe weaknesses in coordination at all scales, from local and regional to national and global. There are many reasons for this lack of c...

The global financial crisis of 2008 has shown that the present financial system involves global systemic risks. The dimension of these risks is hard to grasp with the conceptual tools that have been developed to tackle conventional risks like fire or car accidents. While modern societies know quite well how to deal with conventional risks, we have...

Although the first coronavirus disease 2019 (COVID-19) wave has peaked with the second wave underway, the world is still struggling to manage potential systemic risks and unpredictability of the pandemic. A particular challenge is the "superspreading" of the virus, which starts abruptly, is difficult to predict, and can quickly escalate into medica...

The first phase of the novel coronavirus disease (COVID-19) that emerged at the end of 2019 has been brought under control in the mainland of China in March, while it is still spreading globally. When the pandemic will end is a question of great concern. A logistic model that depicts the growth rules of infected and recovered cases in China’s mainl...

In this article, we recall the United Nations’ 30-year journey in disaster risk reduction strategy and framework, review the latest progress and key scientific and technological questions related to the United Nations disaster risk reduction initiatives, and summarize the framework and contents of disaster risk science research. The object of disas...

The UN sustainable development goals contain environmental, economic, and social objectives. They may only be reached, or at least it would be easier to reach them, if instead of a trade-off between these objectives that implies a need for balancing them, there are synergies to be reaped. This paper discusses how the structures of economic models t...

Changing the scientific approach to fast transitions to a sustainable world. Improving knowledge production for sustainable policy and practice

In 2018, the Intergovernmental Panel on Climate Change (IPCC) produced a special report on the impacts of average global warming of 1.5°C above pre-industrial levels and related global greenhouse gas (GHG) emission pathways. It is set in the context of strengthening the global response to the threat of climate change, sustainable development, and e...

This study proposes an agent-based model to investigate major stakeholders' behaviors in the housing market. The proposed model mimics the heterogeneous behaviors of individual buyers and sellers in a housing market considering bounded rationality. The simulation results of case study in Shanghai are robust and reproduce stylized facts including as...

Although the notion of systemic risk gained prominence with respect to financial systems, it is a generic term that refers to risks of increasing importance in many domains—risks that cannot be tackled by conventional techniques of risk management and governance. We build on a domain-overarching definition of systemic risks by highlighting crucial...

In a globally connected world, new opportunities are associated with new types of risks. These new types of risks do not respect national boundaries nor are they restricted to particular locations or systems. Instead, they are characterized by contagion and proliferation processes, frequently on the basis of a network structure, with the result tha...

Im Kopernikus-Projekt ENavi werden die Rollen von Kommunikationstechnologien (IKT) im Energiesystem und die Chancen der Digitalisierung für die Bereiche Strom, Wärme und Mobilität untersucht.

While most OECD countries have been rather successful in reducing risks to human lives, health, and the quality of the environment, the record for new global risks such as climate change, pandemics, financial breakdowns, and social inequality is much less convincing. This is the challenge of systemic risks. Since the global financial crisis, it has...

Reaching the Sustainable Development Goals requires a fundamental socio-economic transformation accompanied by substantial investment in low-carbon infrastructure. Such a sustainability transition represents a non-marginal change, driven by behavioral factors and systemic interactions. However, typical economic models used to assess a sustainabilit...

The original publication was published without Acknowledgments section. The missing section is printed here.

The complexity of social-ecological systems (SES) is rooted in the outcomes of node activities connected by network topology. Thus far, in network dynamics research, the connectivity degree (CND), indicating how many nodes are connected to a given node, has been the dominant concept. However, connectivity focuses only on network topology, neglectin...

This paper discusses proposals for tabular standards in the late nineteenth and early twentieth centuries. In particular, we focus on Keynes’ proposal for an international tabular standard (ITS) as the gold standard unravelled in the 1930s. The paper explains the origins of Keynes’ ITS proposal which pegged the value of an international reserve to...

GCF Working Paper 2/2017a. Download Link: https://globalclimateforum.org/wp-content/uploads/2017/08/GCF_WorkingPaper2-2017.pdf

We formulate and elicit Bayesian Belief Networks (BBNs) for assessing possible characteristics of the 2030 German new passenger car fleet, including market shares of different vehicle types, CO2 emissions, user costs, and CO2 abatement costs for internal combustion engine vehicles including hybrid electric vehicles (ICE); plug-in hybrid electric ve...

Beyond its obvious macro-economic relevance, fiat money has important micro-economic implications. They matter for addressing No. 8 in Smale's "Mathematical Problems for the Next Century": extend the mathematical model of general equilibrium theory to include price adjustments. In the canonical Arrow-Debreu framework, equilibrium prices are set by...

The UN sustainable development goals contain environmental, economic, and social objectives. They may only be reached, or at least it would be easier to reach them, if instead of a trade-off between these objectives that implies a need for balancing them, there are synergies to be reaped. This paper discusses how the structures of economic models t...

The paper proposes a novel way to handle the relation between decision theory and uncertainty in the context of policy design. Present risk governance is based primarily on two institutions - insurance markets and public risk governance - supported by a powerful theory: the expected utility approach to risk. New systemic risks like those of nuclear...

In our Policy Forum, we argued for the development of a policy dashboard to manage complex financial-economic systems based on an interdisciplinary network analysis and behavioral modeling approach. Ruhl's first point is that legal expertise should be included in the research design. We agree that

Traditional economic theory could not explain, much less predict, the near collapse of the financial system and its long-lasting effects on the global economy. Since the 2008 crisis, there has been increasing interest in using ideas from complexity theory to make sense of economic and financial markets. Concepts, such as tipping points, networks, c...

Multi-actor integrated assessment models based on well-being concepts beyond GDP could support policymakers by highlighting the interrelation of climate change mitigation and other important societal problems.

The Cancun conference decided to establish a Climate Green Fund (CGF) to help developing countries align their development policies with the long-term UNFCCC objectives. This paper clarifies the links between the two underlying motives: the first, technical in nature, is the necessity to redirect the infrastructure instruments in these countries (e...

The concept of entry into and exit out of a crisis mode of socio-ecological systems is a powerful tool for dealing with social learning in the face of large-scale risks. This concept can be used both for descriptive and normative research. We briefly sketch the concept using the example of the European heat wave in 2003.

Coastal areas typically have high social and economic development and are likely to suffer huge losses due to tropical cyclones. These cyclones have a great impact on the transportation network, but there have been a limited number of studies about tropical-cyclone-induced transportation network functional damages, especially in Asia. This study de...

This paper discusses the proposals for a tabular standard in the late 19th and early 20th century, as the gold standard unraveled. In particular, we focus on Keynes’ use of the tabular standard in his own international monetary proposals and consider how sympathetic he was to this idea of linking the value of an international reserve currency to a...

The IPCC's global mean sea-level rise scenarios do not necessarily provide the right information for coastal decision-making and risk management.

Air pollutant emissions from agricultural burning are observed every year after harvest in China. While agriculture is not the main contributor to air pollution in China, agricultural activities can cause severe pollution events. Recognizing the key mechanisms involved in this process offers an opportunity to minimize pollution events caused by agr...

Green growth cannot succeed without significant changes in the education system and the closely related social division of labor. This paper combines historical evidence and a game-theoretic analysis to study the relation between vocational education and green growth. It is found that a low-vocation and a high-vocation equilibrium can be distinguis...

Finance is the supporting means for the implementation of mitigation and adaptation activities in an international climate agreement. However, discussions on finance under the UNFCCC umbrella have come to a stalemate on definitions. The most promising source of finance, the private sector, has become a polarising issue in the negotiations. Yet, out...

This paper explores to what extent moving towards the 30% GHG emission reductions by 2020 with respect to 1990 in the EU can be considered a transformative target. To do so, we first define the concept of transformative targets from a complex systems perspective and show a novel approach and original results using an extended application of the GEM...

Lagom regiO is an agent based model for representing economic systems with several heterogeneous regions – the economy of Germany, the Mediterranean Region, the world – over a time horizon of one to several decades. The model is based on a set of agents including firms, households, a financial system, a government, and the rest of the world. Agents...

This paper presents Lagom regiO: a multi-agent model of several growing economic areas in interaction. The model is part of the Lagom model family: economic multi-agent models developed to make steps toward understanding equilibrium selection and identifying winewin opportunities for climate policy. The particular feature of the model presented her...

Examples of recent large-scale disasters show that the traditional risk management process faces difficulties in dealing with emerging unknowable, unmeasurable, and uncontrollable risks in face of the globalization processes. This article starts with the clarification of the difference between risk management and risk governance, and elaborates the...

At the 100th Dahlem conference New Approaches in Economics after the Financial Crisis a working group devised guidelines for the documentation of computational economic agent-based models, based upon -- but differing from -- the ODD protocol Grimm et al. (2006, 2010). This paper sketches the motivation for coming up with a new set of guidelines tai...

People is the common theme in this part of the RACCM. The part gathers results from the CIRCE project that concern socio-ecological systems all around the Mediterranean. Due to the interdisciplinarity of the project, chapters in this part discuss climate change and societies from different perspectives, such as an economic, social science, or the h...

Is green growth an option for tackling the challenge of climate change in the Mediterranean? The chapter investigates this question in two main steps. First, climate change is analysed in a perspective of fear and in a perspective of con fi dence. Against this background, the most likely but undesirable climate related future for the Mediterranean...

"Integrated Risk Governance: Science Plan and Case Studies of Large-scale Disasters" is the first book in the IHDP-Integrated Risk Governance Project Series. It consists of two parts: Part I: Integrated Risk Governance Project Science Plan, which outlines the challenge, research programme, outcomes, and implementation strategy of the IRG Project; a...

The death toll of recent heat waves in developed countries has been remarkably high, contradicting the common assumption that high levels of economic and technological development automatically lead to lower vulnerability to weather extremes. Future climate change may further increase this vulnerability. In this article we examine some recent evide...

This book provides an evaluation of the science and policy debates on climate change and offers a reframing of the challenges they pose, as understood by key international experts and players in the field. It also gives an important and original perspective on interpreting climate action and provides compelling evidence of the weakness of arguments...

We propose a functional framework for studying agent-based dynamical models of exchange. The framework consists of a notation and of a number of elementary definitions. We argue that – in comparison to narrative descriptions – the framework has a number of advantages: (1) it allows one to express precisely the relationships between the classical no...

Defining and operationalizing Article 2 of the UNFCCC remains a challenge. The question of what is dangerous climate change is not a purely scientific one, as danger necessarily has a subjective dimension and its definition requires judgment and precaution. The papers in this special issue of Regional Environmental Change attempt to navigate this p...

This book provides the reader with a state-of-the-art view of research on sustainable development. Its emphasis lays on the transformative dimension of this research: sustainable development can only be realized through a far-reaching transformation of the situation humankind finds itself in at the beginning of the third millennium. The contributio...

Lagom generic is an agent based model for representing economic systems – the economy of Germany, the Mediterranean Region, the world – over a time horizon of one to several decades. This version contains material related to the working paper "Agent-based dynamics in disaggregated growth models" by Antoine Mandel, Carlo Jaeger, Steffen Fuerst, Wieb...

This paper presents an agent-based model of disaggregated economic systems with endogenous growth features named Lagon GeneriC. This model is thought to represent a proof of concept that dynamically complete and highly disaggregated agent-based models allow to model economies as complex dynamical systems. It is used here for "theory generation", in...

Limiting global warming to 2°C above pre-industrial global mean temperature has become a widely endorsed goal for climate policy. It has also been severely criticized. We show how the limit emerged out of a marginal remark in an early paper about climate policy and distinguish three possible views of it. The catastrophe view sees it as the threshol...

Improving our ability to cope with large risks is one of the key challenges for humankind in this century. This article outlines a research program in this perspective. Starting with a concrete example of a relatively small disaster, it questions simplistic ideas of rationality. It then proposes a fresh look at the concepts of probability and utili...

Auf dem Weg zu einem neuen globalen Klimaabkommen? Dirk Messner Wie die Menschheit die Klimakrise meistern kann APuZ 32–33/2010 15 Es ist möglich, die globalen Treibhausgas-emissionen innerhalb weniger Jahrzehnte praktisch auf Null zu reduzieren, so wie es möglich ist, im selben Zeitraum eine weitge-hende nukleare und konventionelle Abrüs-tung zu r...

This paper discusses the risks of a shutdown of the thermohaline circulation (THC) for the climate system, for ecosystems in and around the North Atlantic as well as for fisheries and agriculture by way of an Integrated Assessment. The climate model simulations are based on greenhouse gas scenarios for the 21st century and beyond. A shutdown of the...

We use a coupled climate–carbon cycle model of intermediate complexity to investigate scenarios of stratospheric sulfur injections as a measure to compensate for CO2-induced global warming. The baseline scenario includes the burning of 5,000GtC of fossil fuels. A full compensation of CO2-induced warming requires a load of about 13MtS in the stratos...

Environmental problems are becoming increasingly complex. They are no longer limited to reducing a toxic by-product of a specific activity by some well-defined technological fix. Rather, for issues like climate change mitigation or integrated water management, intricate interactions among many natural and social systems have to be taken into accoun...

This study models maximum temperatures in Switzerland monitored in twelve locations using the Generalised Extreme Value (GEV) distribution. The parameters of the GEV distribution are determined within a Bayesian framework. We find that the parameters of the underlying distribution underwent a substantial change in the beginning of the 1980s. This c...

The Stern Review has played an enormous role in making the world of business aware of the challenge of long-term climate change. In order to make real progress on the basis of this awareness, it is important to pay attention to the difference between human suffering and losses of gross domestic product (GDP). The Review has compared climate change...

The recent decision of the U.S. Supreme Court on the regulation of CO2 emissions from new motor vehicles shows the need for a robust methodology to evaluate the fraction of attributable risk from such emissions. The methodology must enable decisionmakers to reach practically relevant conclusions on the basis of expert assessments the decisionmakers...

Governments worldwide should provide incentives for initial large-scale GS projects to help build the knowledge base for a mature, internationally harmonized GS regulatory framework. Health, safety, and environmental risks of these early projects can be managed through modifications of existing regulations in the EU, Australia, Canada, and the U.S....

The paper provides global regionalized projections of passenger car demand, use and associated CO2 emissions from 11 world regions. The study is based on empirical data that have been originally collated from international sources for the purpose of modeling region-specific car stock demand. Derived demands serve as indicator of car related fuel co...

Science-based stakeholder dialogues are structured communication processes linking scientists with societal actors, such as representatives of companies, NGOs, governments, and the wider public. Stakeholders possess knowledge needed by scientists to better comprehend, represent and analyse global change problems as well as decision-makers’, manager...

Most models used in climate economics so far are full-employment models. In Germany, as in other countries suffering from persistent unemployment, climate policy can only be successful if it is embedded in an economic policy that generates additional jobs at a large scale. To investigate the possibility for such embedding, a long-term model of the...

When insurance firms, energy companies, governments, NGOs, and other agents strive to manage climatic risks, it is by no way clear what the aggregate outcome should and will be. As a framework for investigating this subject, we present the LAGOM model family. It is based on modules depicting learning social agents. For managing climate risks, our a...

In this paper, we present a new approach to model coupling that probably forms the methodological basis of a new generation of Integrated Assessment models. This approach respects the knowledge and expertise that is embodied in existing models and encourages their gradual evolution. Modularity is the guiding principle. Our approach is distinguished...

When insurance firms, energy companies, governments, NGOs, and other agents strive to manage climatic risks, it is by no way clear what the aggregate outcome should and will be. As a framework for investigating this subject, we present the LAGOM model family. It is based on modules depicting learning social agents. For managing climate risks, our a...

Climate policy needs to address the multidecadal to centennial time scale of climate change. Although the realization of short-term targets is an important first step, to be effective climate policies need to be conceived as long-term programs that will achieve a gradual transition to an essentially emission-free economy on the time scale of a cent...

Building computer models means implementing a mathematical structure on a piece of hardware in such a way that insights about some other phenomenon can be gained, remembered and communicated. For meaningful computer modelling, the phenomenon to be modelled must be described in a logically coherent way. This can be quite difficult, especially when a...