Our Common Future Under Climate Change

International Scientific Conference 7-10 JULY 2015 Paris, France

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Thursday 9 July - 15:00-16:30 UPMC Jussieu - Amphi Astier

3326 - The Mediterranean Basin in a warmer and drier world : challenges and opportunities

Parallel Session

Chair(s): J. Guiot (CNRS, Aix-en-Provence, France)

Convener(s): W. Cramer (IMBE, Marseille, France), J.-P. Gattuso (LOV, Villefranche, France)

15:00

Introduction and Opening remarks

J. Guiot (CNRS, Aix-Marseille Univeristy, Aix-en-Provence, France)

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Introduction and Opening remarks
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15:05

Increased frequency of major heatwaves and droughts in the Mediterranean

R. Trigo (Instituto Dom Luiz - Universidade de Lisboa, Lisbon, Portugal)

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Increased frequency of major heatwaves and droughts in the Mediterranean

R. Trigo (1)
(1) Instituto Dom Luiz - Universidade de Lisboa, Lisbon, Portugal

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The last IPCC Assessment Reports (IPCC, 2007, 2013) identify the Mediterranean region as a climate change and biodiversity “hot spot” with an increasing likelihood of suffering in the future drought episodes and severe heat waves. In fact, most studies using global and regional climate model results suggest that the Mediterranean will experience a general trend towards drier conditions during the 21st century. Thus, the overall tendency towards a drier Mediterranean climate is not independent of the simultaneous increase of the heawaves frequency and magnitude in southern and central Europe. In fact, despite some contradictory results with state-of-the-art models, these combined tendencies towards a drier and more extreme Mediterranean climate fits particularly well into the expected changes predicted by most models for this climate change "hot spot" region (IPCC, 2007, 2013).

Summer heat waves are controlled by intense anticyclonic circulation, often associated with upper tropospheric blocking high. Heat waves have been shown to be responsible for excessive mortality, such as the 2003 heat wave in Western Europe that was associated with an excessive +50,000 fatalities (García-Herrera et al., 2010). Equally, heatwave events can be the main drivers of large wildfires occurrence, such as those that occurred in Portugal in 2003 with more than 430,000 ha burnt area (Trigo et al., 2006). Interestingly, this major heatweave was preceded by very dry conditions (winter and spring) in most of Western Europe, a factor that has been shown to play a crucial role in amplifying the heatwave magnitude (García-Herrera et al., 2010).

The summer of 2010 was exceptionally warm in Eastern Europe and large parts of Russia. In fact the anomalous 2010 warmth that caused adverse impacts exceeded the amplitude and spatial extent of the previous hottest summer of 2003 (Barriopedro et al., 2010). 'Mega-heatwaves' such as the 2003 and 2010 events displayed exceptional seasonal temperatures in a 500-yr long context over approximately 50% of Europe. According to regional multi-model experiments, the probability of a summer experiencing 'mega-heatwaves' will increase by a factor of 5 to 10 within the next 40 years. The results also indicate that the temperature maxima observed during these heatwave episodes were associated with the simultaneous occurrence of outstanding anticyclonic blocking patterns and were preceded by relatively dry soils resulting from the lack of precipitation in winter and spring and an earlier retreat of snow cover.

The western Mediterranean is recurrently affected by drought episodes and therefore by the adverse effects associated that range from severe water shortages to economic losses and related social impacts. During the hydrological years of 2004/2005 and 2011/2012, Iberia was hit by two of the worst drought episodes ever recording in this semi-arid region (Trigo et al., 2013). These two drought episodes were extreme in both its magnitude and spatial extent and appear to fit the tendency towards an increase in the frequency of drought events in the Mediterranean basin (Sousa et al., 2011) partially driven by anthropogenic greenhouse gases emissions (Hoerling et al., 2012; Trigo et al., 2013).

15:20

The Medieval Climate Anomaly and Byzantium. A review of the evidence on economic performance, societal change and climatic fluctuations

E. Xoplaki (Justus-Liebig-University Giessen, Giessen, Germany), D. Fleitmann (University of Reading, Reading, United Kingdom), A. Izdebski (Jagiellonian University, Krakow, Poland), J. Luterbacher (Justus-Liebig-University Giessen, Giessen, Germany), E. Zorita (Helmholtz-Zentrum Geesthacht, Geesthacht, Germany), S. Wagner (Helmholtz-Zentrum Geesthacht, Geesthacht, Germany), I. Telelis (Academy of Athens, Athens, Greece)

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The Medieval Climate Anomaly and Byzantium. A review of the evidence on economic performance, societal change and climatic fluctuations

E. Xoplaki (1) ; D. Fleitmann (2) ; A. Izdebski (3) ; J. Luterbacher (1) ; E. Zorita (4) ; S. Wagner (4) ; I. Telelis (5)
(1) Justus-Liebig-University Giessen, Geography: Climatology, Climate Dynamics and Climate Change, Giessen, Germany; (2) University of Reading, Department of archaeology: school of human and environmental sciences, Reading, United Kingdom; (3) Jagiellonian University, Institute of history: byzantine history department, Krakow, Poland; (4) Helmholtz-Zentrum Geesthacht, Institute for coastal research, Geesthacht, Germany; (5) Academy of Athens, Research center for greek and latin literature, Athens, Greece

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The study of the unusual climate patterns and their impact on ecosystems and societies during medieval times is of considerable interest for scholars of various disciplines such as past, current and future climate researchers, climate impacts scientists, historians, archaeologists, anthropologists, among others. The global, hemispheric and continental climate variability, the associated forcing factors and potential dynamic origin of the Medieval Climate Anomaly (in this work ca. 850 –1300 AD) have been the focus of many studies. Although the wealth of paleoclimate information for the last two millennia available in the Mediterranean basin and to a lesser extent in the Eastern Mediterranean, the character of paleoclimate records in combination with the inhomogeneous proxy records density and distribution during medieval times still restricts scientists from critically assessing the manifestation of the MCA on a regional scale and further to a high temporally and spatially resolved characterization of the climate patterns and associated societal and environmental impacts for specific areas as the Eastern Mediterranean.

During the Medieval Climate Anomaly, Byzantium, a medieval empire encompassing the northern part of the Eastern Mediterranean, had formed an expanding society with a thriving economy and complex political as well as cultural institutions. Byzantium as a medieval society left a considerable body of written evidence, enabling the use of detailed information to investigate potential connections between the societal impact of climate change in the period that spans from the moment when the Byzantine state and economy began to recover after the crisis of the so-called Dark Age, and until the period that followed the fall of Constantinople in AD 1204.

This study aims at assessing the manifestation of the MCA in the Eastern Mediterranean, and linking the existing knowledge about the character and extent of the climatic variability during medieval times in the Eastern Mediterranean, both historical (textual), palaeoenvironmental, and model-based, with what is known about the socio-economic processes taking place in the Byzantine Empire at that time.

15:35

Rising concerns about ocean acidification and warming in the Mediterranean Sea

P. Ziveri (Institute of Environmental Science and Technology (ICTA), Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain)

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Rising concerns about ocean acidification and warming in the Mediterranean Sea

P. Ziveri (1)
(1) Institute of Environmental Science and Technology (ICTA), Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain

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The Mediterranean Sea is facing large biogeochemical changes driven by both climatic and non-climatic drivers. Unprecedented emission rates of CO2 into the atmosphere are responsible for two important drivers such as ocean acidification and warming that are rapidly altering the physico-chemical seawater properties with consequences for the marine ecosystems and ecosystem services.

There are rising concerns since this is one of the regions warming fastest under climate change and acidifying with a similar rate as subtropical regions. This marginal sea have a relatively short residence times and deep waters are likely to lag changes in surface waters by a few decades at most.

I will review here the state of knowledge on the combined effects of ocean acidification and ocean warming in the Mediterranean. Recent results demonstrated that some key organisms that are endemic to the Mediterranean, major contributors to habitat building, and/or ecological function, or species of economic value in the region, are largely affected by the rapid change in pH and/or increase in seawater temperature. The regional vulnerabilities alter the capacity of coastal and marine systems to provide ecosystem services and consequently affect economic activities. 

15:50

Climate Change Distress and Subjective Well Being in Urban coastal cities of India and French Mediterranean region

R. Mudaliar (Aix-Marseille Université-CNRS, Aix-en-Provence, France), A. S. Lindenmannm (Aix-Marseille Université-CNRS, Aix-en-Provence, France)

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Climate Change Distress and Subjective Well Being in Urban coastal cities of India and French Mediterranean region

R. Mudaliar (1) ; AS. Lindenmannm (1)
(1) Aix-Marseille Université-CNRS, UMR ESPACE 7300, Aix-en-Provence, France

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Human-induced global climate change and associated sea level rise (SLR) can have major adverse consequences for coastal ecosystems and societies (Hinkel & Klein, 2003). The IPCC in its various reports has established a clear link among global warming, climate change, SLR and coastal livelihood security. There is growing concern in France of climate change and sea-level rise. There is enough information to identify coastal areas that may be affected. Lambeck and Bard (2000) examined the evidence for relative sea-level change along the French Mediterranean coast. Considerable evidence has been presented in the past two decades for the sea-level change along the French Mediterranean coast. Poumadère et al. (2008) have found that in spite of the stance taken by political figures, general attitudes in France regarding climatic hazards appear to lag behind scientific warnings. The established fact that anthropogenic factors account for one of the major contributors to climate change makes it necessary to probe into behavioral facets as in spite of the best possible efforts around the globe to combat climate change, it is felt that people are still not as seriously aware/ alarmed of the expected future risk as they should be. In view of this, the present study aims at gaining insight into issues of human-climate interaction through a comparative study between coastal cities of India and France. The study is intended at exploring how the coastal population of Indian and French metropolitan cities perceive climate change, how much aware and concerned they are, what guides their opinions, judgments, behaviours, and actions , how efficient they find themselves in adapting with the situation, what adaptive measures would be feasible for them, how competent do they find themselves in terms of coping strategies in relation to the current phenomenon of changing climate. The study enables comparison of data collected from 400 respondents of coastal population of metropolitan areas of Marseille (1,7 million inhabitants), Nice (a little less than 1 million inhabitants) with the researcher's existing data for Indian metropolitan coastal cities of Mumbai and Chennai (400 respondents), both highly vulnerable to climate change related accelerated sea level rise. A specially designed questionnaire called Climate Change Perception Inventory (CCPI) by Rishi et al. (2009) would be used to collect data from French population. The tool is based on Likert type format comprising of 48 items (in its original version) pertaining to perceptual and attitudinal components of climate change.A correlational research study design would be used to study the relation between different study variables which would be subject to regression analysis for making predictions in regard to climate change.

 

 

This study will provide an understanding of mindset of people in urban settlements on climate change. Not only this, it will also help to find out about the level of climate change distress of people with regard to climate change and also what are their actions and reactions in the changing climate scenario. Through Assessment of perceptions and attitudes of people in regard to Cognitive, Conative and Affective dimensions of Human-Climate Interface, one would better be able to determine the level of sharing responsibility regarding changing climate. By studying the pattern of behavioral adaptation to climate change, it would be possible to identify and compare what coping strategies people in coastal cities of India and France are using/ are required to deal with the phenomenon of climate change.The present study is directly in line with Article 6 of New Delhi Work Programme of UNFCCC (2007) in which special effort to foster psychological/behavioral change has been stressed through public awareness. Hence, it fulfills a very strong requirement to conduct behavioral study in the area of climate change.

16:00

Current and future Mediterranean Sea ecosystem functioning in relation with global change: The MERMEX/MISTRALS project

R. Sempéré (CNRS, Marseille, France), X. Durrieu De Madron (CEFREM, Perpignan, France), C. Guieu (CNRS-UPMC, Villefranche sur mer, France), I. Pairaud (IFREMER, La Seyne/mer, France)

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Current and future Mediterranean Sea ecosystem functioning in relation with global change: The MERMEX/MISTRALS project

R. Sempéré (1) ; X. Durrieu De Madron (2) ; C. Guieu (3) ; I. Pairaud (4)
(1) CNRS, Mediterranean Institute of Oceanography (MIO), Marseille, France; (2) CEFREM, Cnrs-université de perpignan, Perpignan, France; (3) CNRS-UPMC, Villefranche sur mer, France; (4) IFREMER, Lerpac, La Seyne/mer, France

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The semi-enclosed nature of the Mediterranean Sea, together with its smaller inertia due to the relative short residence time of its water masses, make it highly reactive to external forcing, in particular variations of water, energy and matter fluxes at the interfaces. This region, which has been identified as a ‘‘hotspot’’ for climate change, is therefore expected to experience environmental impacts that are considerably greater than those in many other places around the world. These natural pressures interact with the increasing demographic and economic developments occurring heterogeneously in the coastal zone, making the Mediterranean even more sensitive. The current knowledge on and expected changes due to single forcing (hydrodynamics, solar radiation, temperature and acidification, chemical contaminants) and combined forcing (nutrient sources and stoichiometry, extreme events) affecting the biogeochemical fluxes and ecosystem functioning are explored within the project MERMEX in the framework of MISTRALS program. MERMEX project based on MERMEX group white book (*) is dedicated to the response of Mediterranean ecosystems and biodiversity to climate changes and anthropogenic pressure. MERMEX aims to deepen the current understanding of the Mediterranean marine ecosystems to better anticipate their upcoming evolution. It is focusing on the response of ecosystems to modifications of physico-chemical forcing at various scales, both in time and space, linked to changing environmental conditions and increasing human pressure. Four years MERMEX results clearly showed that several processes including winter dense surface water convection, surface water stratification, river water discharge and episodic desert dust inputs play a major role on marine productivity as well as on organism community structure. Slight modifications of such processes that will be very likely affected by global change in 21th century can induce significant changes in Mediterranean Sea ecosystems.

 

 (*) The MERMEX group, (2011) Marine ecosystems' responses to climatic and anthropogenic forcings in the Mediterranean, Progress In Oceanography, 91: 593-594.

16:10

Climate Change Impact on Mediterranean Forest Functioning

V. Baldy (Aix-Marseille University, Marseille, France), C. Fernandez (Aix-Marseille University, Marseille, France), I. M. Reiter (CNRS, Aix-en-provence, France), E. Ormeno (CNRS, Marseille, France), J.-P. Orts (CNRS, Marseille, France), M. Santonja (Aix-Marseille University, Marseille, France), A.-C. Génard (Aix-Marseille University, Marseille, France), A. Bousquet-Mélou (Aix-Marseille University, Marseille, France), C. Boissard (Universite Paris Diderot, Paris, France), G. Castagnoli (CNRS, Saint Michel l'Observatoire , France), A. Rotereau (CNRS, Aix-en-provence, France), T. Gauquelin (Aix-Marseille University, Marseille, France)

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Climate Change Impact on Mediterranean Forest Functioning

V. Baldy (1) ; C. Fernandez (1) ; IM. Reiter (2) ; E. Ormeno (3) ; JP. Orts (3) ; M. Santonja (1) ; AC. Génard (1) ; A. Bousquet-Mélou (1) ; C. Boissard (4) ; G. Castagnoli (5) ; A. Rotereau (2) ; T. Gauquelin (1)
(1) Aix-Marseille University, IMBE, Marseille, France; (2) CNRS, Eccorev, Aix-en-provence, France; (3) CNRS, Imbe, Marseille, France; (4) Universite Paris Diderot, Lsce, Paris, France; (5) CNRS, Ohp-osu pytheas, Saint Michel l'Observatoire , France

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The combination of significant past and current anthropogenic pressure and high level of biodiversity makes the Mediterranean one of the world’s most threatened regions by current change, warranting its classification as a biome “in crisis”. Mediterranean forests play major ecological, social and economic roles by providing goods and services and thereby represent a great asset and opportunity for the future of the Mediterranean. The functioning of Mediterranean forests is contingent on the existence of the dry summer period. Intensified and prolonged drought periods related to climate change are then of special concern in these ecosystems. Currently, our understanding of the response, in terms of biodiversity and functioning of Mediterranean forests to extreme drought conditions is limited. A wide variety of methodological approaches have been put into practice to examine the mechanisms by which climate change could alter the functioning of terrestrial ecosystems, such as the study of altitudinal climatic gradients, latitudinal transects, and the experimental modification of precipitation or warming. Controlled field experiments are however costly and difficult to operate on a large scale without introducing environmental modifications. Further, the investigations of ecosystem functioning in relation to climate change are very demanding, as they require multi-scale and interdisciplinary research maintained over long time-spans. We set up an experimental facility with a rain exclusion system and a network of various sensors at different levels of the forest situated in a French Mediterranean natural old-growth oak forest, the Oak Observatory at the OHP (O3HP).

This observatory allows investigating functional components of the ecosystem such as phenology, growth, litter decomposition and emission of biogenic volatile organic compounds by trees. Moreover, functional changes in biodiversity-related traits in the context of a drier climate are monitored, particularly the role of soil biodiversity in the biogeochemical cycle.

The first results show a significant effect of the experimental increase of the summer-drought period. For example, prolonged drought slows down litter decomposition and consequently nutrient availability, and initially increased to eventually decrease the emission rates of volatile organic compounds by trees in the course of the drought period. These results point-out the importance of addressing climate change on future management practices for the sustainable development of Mediterranean forest ecosystems.

 

16:20

Lessons from the Past: Modeling past human adaptation to climatic change in the Mediterranean Basin

A. Kirman (Aix Marseille University, Aix en Provence, France), A. Bondeau (Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale, Aix-en-Provence, France), D. Contreras, (Aix Marseille University, Aix en Provence, France), J. Guiot (CNRS, Aix-en-Provence, France), N. Hanaki (Aix Marseille University, Aix en Provence, France), S. Thoron (Universite Paris Est Creteil, Paris, France)

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Lessons from the Past: Modeling past human adaptation to climatic change in the Mediterranean Basin

A. Kirman (1) ; A. Bondeau (2) ; D. Contreras, (3) ; J. Guiot (4) ; N. Hanaki (1) ; S. Thoron (5)
(1) Aix Marseille University, GREQAM, Aix en Provence, France; (2) Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale, Aix-en-Provence, France; (3) Aix Marseille University, Ot-med, Aix en Provence, France; (4) CNRS, CEREGE, Aix-en-Provence, France; (5) Universite Paris Est Creteil, Liphar, Paris, France

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The Mediterranean Basin has a well-documented history of climatic fluctuations throughout the span of its human occupation.  Detailing past climatic changes and predicting those in the future is thought of as the task for sophisticated climate modeling, while investigating the human consequences of climate change remains a challenge for the social sciences.  The AMENOPHYS Project combines the two and explores the limits of cultural adaptability to climatic shifts in the Mediterranean through a modeling approach, combining paleoclimatic data, GIS-based landscape evolution modeling, agroecosystem modeling, and agent-based modeling to ask how past climate change in the Mediterranean directly affected the lives of the region’s inhabitants, and which factors were most salient in rendering climatic changes more or less survivable. 

There is an abundance of literature – archaeological, historical, paleoclimatic, and paleoenvironmental – born out of the reasonable premise that past climatic shifts were of magnitudes that must have had cultural consequences.  Such work, however, has struggled to move beyond correlation; we aim to articulate these links between paleoenvironmental and cultural change and to thereby tackle what has been a persistent challenge. This will improve our understanding of cultural trajectories, of human ecological footprints, and provide a strategy for untangling human and environmental histories in the long term.  It will make past human experience directly relevant to current global realities and challenges.  

Our models aim to provide explicit, well-formulated mechanisms linking humans and environments, thereby enabling the articulation of testable hypotheses that can be compared to empirical evidence.  Questions of scale and resolution are fundamental.  Environmental parameters are generally the purview of environmental modeling and paleoclimate studies – where spatial scales are regional and temporal scales are centennial, if not millennial.  In contrast, social scientific explanation relies fundamentally on anthropological models of behavior – i.e., human decision-making at local and annual or decadal scales. 

Agent based modeling can contribute significantly to reducing this important interpretative gap. We model the human consequences of climatic change, with a view to exploring their variability across different geographies, production regimes (i.e., subsistence practice and technology, and available resources), demographic, sociopolitical and economic contexts, and environmental inheritances. This will provide a means of articulating linking mechanisms where they cannot be directly observed.

Using landscape evolution and agroecosystem models in a feedback system with agent-based models of small Mediterranean communities, and starting from a specific example of Provençal geography,this project explores the effects of climatic shifts, legacies of human activity, available subsistence options and technologies, and community size and organization on vulnerability and resilience.