Prof. Dr. Hermann Held
Photo: Clisap
Executive Director FNK
Sustainability and Global Change
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Hermann Held joined the University of Hamburg as professor of ‘Sustainability and Global Change’ in 2010. Before, he had appointments as PostDoc, then department CoChair at the Potsdam Institute for Climate Impact Research (PIK). He is a physicist by training and received his PhD from the University of Munich. He serves as Editorial Board Member for the Journal Earth System Dynamics.
His research includes decision-making under heterogenous uncertainty and early warning of tipping points for integrated assessment. His current work strives for dynamically consistent decision-making under environment targets as an expression of the precautionary principle.
Curriculum Vitae
Main Research Interests
- Dynamically consistent decision-making under environmental targets under uncertainty
- Integrated assessment of climatic change mitigation options
- Risk management of side-effects of climate policy options
Research Accomplishments
The first phase within climate research was devoted to the reduction of uncertainty in climate (impact) projections. Initiation and lead of a research project to reduce uncertainty of climate sensitivity by nonlinear assimilation of paleo data, using an Earth system model of intermediate complexity. It was demonstrated that a dynamically consistent assimilation of paleo data has the potential to reduce the uncertainty of climate sensitivity by a factor of 2 and to convert the high-end fat tail of the sensitivity’s distribution into a slim one. A similar approach was demonstrated for the determination of ocean heat uptake.
Furthermore, an early warning system for reaching saddle node bifurcations in complex systems was developed.
The representation of deep uncertainty as Knightian uncertainty was advanced in discussing various approaches in the context of generalized Bayesian learning. Two new update rules were introduced that mimic society’s preferences better when having to deal with the advent of new information in a situation of deep uncertainty such as for the climate problem.
Market-based risk management tools were analyzed for geological carbon storage (presented during hearings of parliaments at the national and county level) and climate-induced increases in storm losses within the building sector (stakeholder project with the German insurance association). Global warming within the 21st century was found a manageable issue at the national level for that sector.
Finally, a dynamically consistent method for decision-making under environmental targets was developed and applied to the Paris Agreement (2015). The thereby expressed preference order was extended to evaluate solar radiation management in a consistent manner.
Biography
Short Biography
| Since 2010 | Professor of Sustainability and Global Change, Universität Hamburg, with the departments of ‘Earth System Sciences’ and ‘Economics’ |
| 1999-2010 | PostDoc, then Department CoChair at the Potsdam Institute for Climate Impact Research (PIK) |
| 1998-1999 | Feodor Lynen-Fellow of the Alexander von Humboldt-Foundation: Post-Doc at UC Berkeley on non-linear analysis of molecular surface structures; work at LBNL/Berkeley on risk assessment methodologies. |
| 1996-1999 | Research assistant on Quantum Chaos at the University of Munich (granted to leave for AvH-fellowship 05/1998 - 08/1999); ‘C1’ since 12/1997. |
| 1993-1996 | PhD programme fellow by the Max Planck Society at the Max Planck Institute for Quantum Optics |
| 1986-1993 | Study of Physics at University of Kiel, ETH Zürich, University of Munich (LMU) |
Boards and Community Service
| Since 2020 |
Intermittently EAERE (European Association of Environmental and Resource Economists) Scientific Programme Committee Member (in 2020, 2023, 2024) |
| Since 2018 | Member of the German IIASA (International Institute for Applied Systems Analysis, Laxenburg, Austria) Committee |
| 2018-2022 | Review Editor for IPCC AR6 WGIII Ch17 |
| Since 2017 | Executive board member of the Helmholtz-Institut Climate Service Science (HICSS) |
| 2013-2016 | Member of the CE-SPP Executive Board (DFG priority programme) ‘Climate engineering – Risks, Challenges, Opportunities?’ |
| 2011-2024 | Member of the Scientific Steering Committees of Hamburg’s Clusters of Excellence on Climate (CliSAP, CLICCS) |
| Since 2011 | Member of the Scientific Advisory Board of the Wegener Center for Climate and Global Change at the University of Graz, Austria |
| 2010-2014 | Lead Author for IPCC AR5 WGIII Ch2 |
| 2010-2015 | Editorial Board Member of Earth System Dynamics |
| 2009 | Coordinator for Germany in an EIT-KIC-proposal on climate April-August 2009 (PIK together with ETHZ, Imperial College, IPSL/ParisTech, U Utrecht; German node: TU Berlin, TU Munich, GFZ Potsdam) until submission of proposal (granted 16th December 2009). |
| 2005-2009 | Maximum term elected president for EGU-ERE (European Geoscience Union – Energy, Resources and the Environment) – re-elected in 2007. |
Advisory Committees
| Since 2019 | Representative of Universität Hamburg at KlimaCampus Hamburg Round Table; 2019-2021 also member of the Coordination Team |
| 2016 - 2024 | Advisory Council Member of Hamburg’s Foundation for Climate Protection (Stiftungsrat der Hamburger Klimaschutzstiftung) |
| 2012 - 2017 | Member of the German Bishops' Conference Research Group on the Universal Tasks of the Church (Wissenschaftliche Arbeitsgruppe für weltkirchliche Aufgaben der Deutschen Bischofskonferenz); contribution on sustainable development |
| 2011 - 2015 | Member of the Advisory Board of the aid organisation MISEREOR |
Selected Publications
- B. Blanz, R. Cormier, D. Swain, H. Held, Adding the risk of stock collapse over time to stock assessments and harvest allocation decisions. ICES Journal of Marine Science, fsae084. https://doi.org/10.1093/icesjms/fsae084 (2024).
- M. Mohammadi Khabbazan, M. Stankoweit, E. Roshan, H. Schmidt, H. Held, How can solar geoengineering and mitigation be combined under climate targets? Earth System Dynamics 12, 1529–1542, https://doi.org/10.5194/esd-12-1529-2021 (2021).
- C. Li, H. Held, S. Hokamp, J. Marotzke, Optimal temperature overshoot profile found by limiting global sea-level rise as a lower-cost climate target, Science Advances, 6 (2), eaaw9490, DOI: 10.1126/sciadv.aaw9490 (2020).
- H. Held, Cost Risk Analysis – Dynamically Consistent Decision-Making under Climate Targets, Environmental and Resource Economics, 72 (1), 247-261, DOI10.1007/s10640-018-0288-y, http://link.springer.com/article/10.1007/s10640-018-0288-y (2019).
- E. Roshan, M. Mohammadi Khabbazan, H. Held, Cost-Risk Trade-off of Mitigation and Solar Geoengineering – Considering Regional Disparities under Probabilistic Climate Sensitivity, Environmental and Resource Economics, 72 (1), 263-279, DOI 10.1007/s10640-018-0261-9, http://link.springer.com/article/10.1007/s10640-018-0261-9 (2019).
- D. Neubersch, H. Held, A. Otto, Operationalizing climate targets under learning: An application of cost-risk analysis, Climatic Change, 126 (3), 305-318, DOI 10.1007/s10584-014-1223-z (2014).
- M. G. W. Schmidt, A. Lorenz, H. Held, E. Kriegler, Climate Targets under Uncertainty: Challenges and Remedies, Climatic Change Letters, 104 (3-4), 783-791, DOI 10.1007/s10584-010-9985-4 (2011).
- H. Held, E. Kriegler, K. Lessmann, O. Edenhofer, Efficient Climate Policies under Technology and Climate Uncertainty, Energy Economics 31, S50–S61 (contribution in C. Böhringer, T. P. Mennel, T. F. Rutherford (Guest Eds.): Technological Change and Uncertainty in Environmental Economics), doi:10.1016/j.eneco.2008.12.012 (2009).
- T. M. Lenton, H. Held, E. Kriegler, J. Hall, W. Lucht, S. Rahmstorf, H. J. Schellnhuber, Tipping elements in the Earth’s climate system, PNAS, 105 (6), 1786-1793, www.pnas.org/cgi/doi/10.1073/pnas.0705414105 (2008).
- H. Held, T. Kleinen, Detection of climate system bifurcations by degenerate fingerprinting, Geophys. Res. Lett. 31, L23207, doi:10.1029/2004GL020972 (2004).