Ecole Normale Supérieure
CERES-ERTI
Centre d'Enseignement et de Recherches sur l'Environnement et la Société
Environmental Research and Teaching Institute
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Projects

Title Funding Involved CERES-ERTI members DescriptionLinks/docs
Extreme Events, Causes and Consequences (E2C2) European Commission FP6 Michael Ghil (PI), Patrice DumasExtreme events are a key manifestation of complex systems, in both the natural and human world. Their economic and social consequences are a matter of enormous concern. Much of science has concentrated, until recently, on understanding the mean behaviour of physical, biological or social systems and their 'normal' variability. Extreme events, due to their rarity, have been hard to study and even harder to predict. E2-C2 secures the cross-national, cross-institutional and cross-disciplinary collaboration and interaction needed to maintain and further strengthen Europe's position as a world leading provider of the basic understanding of extreme events, long-range persistence and crisis modelling. Such a status is of key importance for policy makers and governmental bodies to ensure proper, scientifically based knowledge for assessing human-induced global and regional climate change problems, and for estimating the risks and costs of such a change. By bringing together a diverse consortium of experts to address a few key problems, E2C2 will add substantial value to the activities of the individual partners. For instance, state-of-the-art models that require expertise from both fields will treat the climate-economy interaction. Several inherently interdisciplinary WPs will enrich each of the involved fields: statistics, mathematics, geosciences, and economics. Our research will also benefit from the partners' national projects and base funding. In this way, E2C2 will act as a catalyst to optimise the existing funding on an institutional and a national level. Finally, all of the knowledge and results obtained in E2C2 will be transferred to the scientific community in Europe and outside it, by means of a dedicated E2C2 workshop, which will ensure the knowledge transfer and stimulating trans-disciplinary exchanges of data, techniques and concepts. website
Climate model robustness: uncertainties, dynamical systems, and the fate of planet Earth - Robustesse des modèles climatiques : fourchette d'incertitudes, systèmes dynamiques et l'avenir de la planète (FISDAP) CNRS-ISC (Institut des Systèmes Complexes) Michael Ghil (PI), Mickael Chekroun Collaborators: Hervé Le Treut (LMD, CNRS and IPSL), Jean-Pierre Nadal (LPS, ENS) and Eric Simonnet (INLN, Nice).

Objectives: The main objective of this proposal is to develop methods for reducing the range of projections in future climate change and increasing the confidence in these projections. This objective is to be achieved by (i) increasing the fundamental understanding of the reason for discrepancies between the simulations of past and current climate, as performed by distinct models or by different versions of the same model; and (ii) based on this understanding, analyze the range of future climate projections and devise tools for systematically reducing it.

Invited and contributed talks and posters

  • Invited talk at Joint Mathematics Meetings 2008, January 6--9, San Diego.
  • Invited talk at the Climate Seminar, Harvard, 6 March 2008.
  • Invited talk at the American Physical Society Mtg., March 2008, New Orleans.
  • Publications

  • Ghil, M., M. D. Chekroun, and E. Simonnet, 2008: Climate dynamics and fluid mechanics: Natural variability and related uncertainties, invited survey paper for Special Issue on "The Euler Equations: 250 Years On", Physica D, 237, 2111-2126, doi:10.1016/j.physd.2008.03.036
  • Hillerbrand, R., and M. Ghil, 2008: Anthropogenic climate change: Scientific uncertainties and moral dilemmas, invited paper for Special Issue on "The Euler Equations: 250 Years On," Physica D, 237, 2132-2138, doi:10.1016/j.physd.2008.02.015
  • Ghil, M., I. Zaliapin, and B. Coluzzi, 2008: Boolean delay equations: A simple way of looking at complex systems, Physica D, 237, 2967-2986, doi: 10.1016/j.physd.2008.07.006.
  • Appel à idées

    Pre project

    Modélisation interface environnement/sociétésRD2S, CIREDBarbara Coluzzi, Michael GhilL'objectif de ce projet exploratoire est le développement, la validation et l'application de méthodes mathématiques utilisant les équations booléennes avec retards (en anglais "Boolean delay equations" or BDEs), pour permettre l'analyse des rétroactions au sein de réseaux interdépendants dans le cadre de la modélisation intégrée environnement-sociétés. En particulier, il s'agit d'obtenir des résultats qualitatifs sur la durabilité de certains comportements, à des niveaux acceptables, en l' absence de mesures suffisamment complètes pour permettre l' application d'outils de modélisation plus "classiques", comme les systèmes d'équations différentielles ou aux dérivées partielles. En effet, toute modélisation classique, du type "modèle de circulation générale" climatique ou modèle "input-output" en économie, demande la connaissance assez précise d'un grand nombre de paramètres pour sa calibration ; or ces paramètres ne sont souvent connus qu'à un facteur de 2, 3 ou 10 près. En accord avec le principe de précaution, nous proposons d'adapter les BDEs à l'étude préliminaire des phénomènes couplés nature-société, en attendant des connaissances et mesures plus complètes, permettant alors la modélisation classique de ces phénomènes et des résultats plus quantitatifs sur la pérennité des comportements associés. Les comportements à étudier peuvent porter sur des systèmes naturels, comme le climat régional et ses interactions avec le climat européen et global, ou la biodiversité régionale et ses interactions avec le climat régional ou de l'Europe. Ils peuvent aussi porter sur des comportements socio-économiques, influencés par et influençant à leur tour les changements climatiques ou biologiques.
    Physiologically structured population models for viability analysis RD2SDavid Claessen

    Population persistence is notably conditioned by the degree of individual variation in reproductive success, which depends on variation in any part of the life cycle. Yet, the majority of studies that examined population extinction have tended to ignore life history variation and plasticity. Here, we wish to use life history models to inform the dynamics of small populations and ask how plasticity in life history traits influences extinction dynamics. Many aspects of life history can interact with population dynamics and the project concentrates on three of them, namely growth, maturation and survival. The post-doc will explore this issue by developing models that account for variation in life history traits using the theory of physiologically structured populations (PSP). This theory takes into account that physiological development (e.g. growth, maturation) depends on the current state of the environment (e.g., temperature, food and predator densities). In turn, the influence of the population on the environment closes a feedback loop between environment, population and life history. The theory of PSP models is thus particularly well-suited to study the interaction between population dynamics and plastic life history. Small populations are subject to stochastic fluctuation in abundance. The project aims to study the feedback of this variability on life history and the consequences for extinction dynamics. The models will be parameterized with estimates from field and experimental studies undertaken with the common lizard, a species with strong thermal and food plasticity in life history traits.

    The post-doc will be based at the Ecology-Evolution Laboratory (CNRS, UMR 7625) at the Ecole Normale Supérieure (CERES-ERTI) in Paris, where the applicant will work with David Claessen and Jean-François Le Galliard.

    Call for postdoc
    ENSEMBLESEuropean Commission FP6Michael GhilThe project aims to:

    * Develop an ensemble prediction system for climate change based on the principal state-of-the-art, high resolution, global and regional Earth System models developed in Europe, validated against quality controlled, high resolution gridded datasets for Europe, to produce for the first time, an objective probabilistic estimate of uncertainty in future climate at the seasonal to decadal and longer timescales

    * Quantify and reduce the uncertainty in the representation of physical, chemical, biological and human-related feedbacks in the Earth System (including water resource, land use, and air quality issues, and carbon cycle feedbacks)

    * Maximise the exploitation of the results by linking the outputs of the ensemble prediction system to a range of applications, including agriculture, health, food security, energy, water resources, insurance and weather risk management

    Michael Ghil is responsible for Work Package 8.4: PhD training and staff exchange programs, to allow the spin-off from the research and development that will take place within ENSEMBLES working groups to be made available to young and confirmed scientists.

    website



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