Mri suzhou 27052011
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Why we should care about mountains
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Mri suzhou 27052011
- 1. Global Change in Mountain Regions: What Does It Mean and Why Should You Care? Greg Greenwood Executive Director, Mountain Research Initiative University of Bern, Switzerland Suzhou, China, 26 May 2011 Mountain research initiative
- 4. MRI is part of the Earth System Science Partnership ( http://www.essp.org/) Global Land Project (GLP) joint project of IGBP and IHDP http://www.globallandproject.org/
- 5. Switzerland supports other international global change projects: Global Mountain Biodiversity Assessment (GMBA) and Past Global Changes (PAGES)
- 6. Switzerland also hosts and supports Working Group 1 (Physical Science Basis) of the Intergovernmental Panel on Climate Change
- 7. The University of Bern is renown for mountain and climate research
- 10. China is the largest country that is more than 50% mountainous
- 11. Water (3x) Protection Resource extraction Global significance of mountain regions Qualitative considerations: Ecosystem goods & services (1/2)
- 12. DATA FROM ADAM AND LETTENMAIER (2003) AND ADAM ET AL., (2005), GLOBAL AVERAGE: EXCLUDING ANTARCTICA COMPLEX TERRAIN: 887 MM/Y;(“FLAT” TERRAIN: 768 MM/Y) (Slide from Rick Lawford, GEWEX) More precip over complex terrain (except in SA) NA: 957 MM/Y (640 MM/Y) SA: 1345 MM/Y (1784 MM/Y) EA: 746 MM/Y (552 MM/Y) AF: 887 MM/Y (689 MM/Y )
- 14. Mountains are “Water Towers”
- 15. Landslides pose a threat..Zhouqu, 2010
- 17. Tourism Biodiversity Carbon storage Global significance of mountain regions Qualitative considerations: Ecosystem goods & services (2/2)
- 18. Mountains are centers of biodiversity
- 19. Mountains are centers of tourism
- 21. (slide from Andreas Hemp, University of Bayreuth)
- 22. Gravity makes mountains dynamic: water, rock, fire...
- 23. Gravity makes mountains dynamic: water, rock, fire...
- 24. Gravity makes mountains dynamic: water, rock, fire...
- 25. Gravity makes mountains dynamic: water, rock, fire...
- 26. Thermally Driven Circulations Whiteman (2000)
- 27. Strong Stability: Low Level Airflow Blocked Weak Stability: Airflow Follows Hill Contour Dynamics of Orographic Precipitation Summary Unstable Case: Precip/Convective Cells Microphysics and 3D Multiscale Terrain seeder feeder (slide from Richard Rotunno, NCAR)
- 29. IPCC model simulations with 2x CO 2 show temperature change increases with altitude °N °S Climate change may be amplified in mountain regions Example: The American Cordillera
- 30. 20 th century warming is more important in the Alps Rebetez & Reinhard In press + 0.57 °C / decade Temperature anomaly [°C] (slide from Pascal Vittoz and Antoine Guisan, UniL)
- 31. Climate scenario for Central Alps 0 50 100 150 1 2 3 4 5 6 7 8 9 10 11 12 Temperature (°C) Precipitation (mm) Month Month Future climate downscaled based on simulations with regional climate model (CHRM56 A2, Schär et al . 2004) (slide from Harald Bugmann, ETHZ) Current climate (1960-2000) Future climate (2070-2100)
- 32. Consequences for floods: the buffering effects of snow Runoff Flood level (slide from Martin Beniston, University of Geneva)
- 33. Temperature trends (station data) Vuille & Bradley, 2000, Geophys. Res. Lett. Vuille et al., 2003 , Clim. Change
- 34. Climate change is amplified in mountain regions Tibetan Plateau: Trends in surface air temperature with elevation: 1961-90
- 35. Possible shifts in snow duration for a projected climatic change in the Alps 25 50 75 100 125 150 175 200 225 250 275 300 325 350 Snowpack duration [days] Mean winter temperatures [°C] Mean winter precipitation [mm/day] Beniston et al, 2003: Theoretical and Applied Climatology (slide from Martin Beniston, University of Geneva) -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 1 2 3 4 5 6 7 8 9 10 2081-2090 2091-2100 2071-2080 Säntis: Future climate Arosa: Current climate Arosa: Future climate 2071-2080 2081-2090 2091-2100 Säntis: Current climate
- 36. Changes in the extent of Muskulak glacier (Notgemeinschaftsgletscher) (slide from Ludwig Braun, Bavarian Academy of Science and Humanities)
- 37. 2 x CO 2 no glaciation Cool summer, low runoff Warm summer, high runoff The loss of glaciers = loss of late summer runoff
- 38. Climate change in mountains affects water supply current average snow water equivalent in Sierra Nevada (CA) (Knowles and Cayan 2004) Current average April snow water equivalent in Sierra Nevada (CA) Percent reduction in April SWE with 1.6 °C rise by 2060 Even in non-glaciated mountains such as in Central California, warming will lead to more rain and less snow, and earlier melting, Shifting the timing of fresh water runoff impacts Delta water quality more in winter = flooding? less in summer = salt-water intrusion
- 40. Transient plant dispersion with warming L. perenne , +5.8°C by 2100, dispersion: 40 m/ yr Randin, Engler et al. (in prep) Milleret (2004) Master MigClim model (slide from Antoine Guisan, University of Lausanne) 2000 2005 2010 2015 2020 2025 2030 2040 2045 2035 2060 2065 2070 2075 2080 2085 2090 Colonized surface per 5 years 2050 2055 2095 2100 Temperature increase [°K]
- 41. Winners and losers with climate change gained stable lost never present Present 2100 + 6.2 °C ∩ present absent ∩ = = present absent Lolium perenne Saxifraga oppositifolia Randin et al. In prep.
- 42. Species turnover and extinctions Randin et al. (in prep.) D. octopetala E. myosuroides L. alpinus A. elatius V. tripteris S. minor All species different in 2100 A1 scenario (slide from Antoine Guisan, University of Lausanne) 25 100 % sp turnover by 2100: winners losers Committed to extinction? gaining > 200% 201 Number of species (N = 287) % area lost or gained -100 0 220 0 130 86
- 44. Effect of dispersal distance on future predicted area of occupancy +5.8°C by 2100 Lolium perenne Engler & Guisan (in revision) km 2 unlimited 100 m 40 m 20 m 10 m 5 m Dispersal distance (per year): Predicted area of occupancy Years (slide from Antoine Guisan, University of Lausanne)
- 46. (slide from Andreas Hemp, University of Bayreuth)
- 47. (slide from Andreas Hemp, University of Bayreuth)
- 48. Impacts: range shifts and disturbances Schumacher & Bugmann (2006), GCB Future climate (2080)
- 50. Escapes in the future driven by WIND.. Los Angeles San Diego Grass Brush Forest Number of escapes
- 51. Changing the climate, changing the rules: global warming and insect disturbance in western North American forests Allan L. Carroll Canadian Forest Service Pacific Forestry Centre Victoria, BC Natural Resources Canada Ressources naturelles Canada Canada http://mri.scnatweb.ch/content/view/141/73/ and look for Allan Carroll
- 58. How can we adapt the GLP approach to the Third Pole? MRI is working with INSTITUTE OF TIBETAN PLATEAU RESEARCH/CAS http://www.tpe.ac.cn/home
- 59. How does one actually implement this? Earth System (global) Land Systems (Third Pole) Social Systems Population Political/Institutional Regimes Culture Ecosystems Biogeochemistry Biodiversity Vegetation Soil Resource Use & Management Decision Making Flowing & Standing Water Cryosphere Pollution Livelihood Groups Ecosystem Services & Hazards Circulation, forcings
- 60. “ Putting names to fluxes”... Charles J. V örösmarty 2006
- 61. Earth System (global) Land Systems (Third Pole) Social Systems Population Political/Institutional Regimes Culture Ecosystems Biogeochemistry Biodiversity Vegetation Soil Resource Use & Management Decision Making Flowing & Standing Water Cryosphere Pollution Livelihood Groups Ecosystem Services & Hazards Circulation, forcings Whose names go in the boxes? Earth System Drivers: Prof. ?? Ecosystem Conditions: Prof. ?? Ecosystem Services: Prof. ?? Feedbacks to Earth System Resource Benefits: Prof. ?? Current Resource Use: Prof. ?? Impacts of use Nature of the Social System Decision Making Processes: Prof. ?? A human resources project..
- 62. at what scale? from M. Menenti 2010
- 63. We could do this at range or basin scale..who does what where? Sanjiangyuan Hengduan Chang Tang Yarlung Kosi Karakorum Ladakh Kun Lun Pamir Tian Shan from M. Menenti 2010
- 64. Different socio-economic systems co-exist on the Third Pole Vegetation Land use Hydrology: soil water, stream discharge Meteorological and climatic “forcings”: precip, temp, radiation Pastoral Cropping Gathering
- 65. THANK YOU FOR YOUR ATTENTION
Notas do Editor
- Thank you. Some of you may recall that we are in the midst of the International Polar Year. This afternoon I would like to address the impacts of climate change on what is truly the third pole of the plant, its mountain regions.
- While the role and importance of mountains in global change research was manifested with IGBP from the early 1990’s, the MRI took concrete conceptual form with the publication in 1999 of this report. MRI differs from many (but not all) of the global change projects supported by the umbrella organizations in that if focuses on a place, as opposed to an element or a system. As such the MRI incorporates both biophysical and socio-economic aspects of global change. MRI is in a certain sense the new Global Lands Project for mountains, as GLP , the successor to the Land Use and Cover Change Project, has been specifically constructed as a project that takes a whole system view of the land system, including both human and biophysical aspects. This linkage led as well to endorsements by GTOS (with its emphasis on observations) and MAB (with its emphasis of the interaction between people and the biosphere). The Coordination Office of MRI in Bern Switzerland has been supported by a grant from the Swiss National Science Foundation running from 2004 to October 2007. This grant is an expression of both Swiss scientific interest in climate change and in mountain research, and of Swiss foreign policy in support of international scientific cooperation and of mountain regions throughout the world.
- Some of you may be familiar with the Global Mountain Biodiversity Assessment, also looked in Switzerland at the University of Basel and headed by. Christian Körner. (click) GMBA and MRI are sister programs: whenever MRI encounters issues related to biodiversity it consulted with GMBA. (click)GMBA is endorsed by Diversitas, just as MRI is endorsed by IGBP and IHDP. (click) MRI has begun consulting more frequently with WCRP, especially with respect to Climate and the Cyrosphere. It may make sense to seek a more formal endorsement by WCRP: after you see this presentation we would be interested in your thoughts.
- Some of you may be familiar with the Global Mountain Biodiversity Assessment, also looked in Switzerland at the University of Basel and headed by. Christian Körner. (click) GMBA and MRI are sister programs: whenever MRI encounters issues related to biodiversity it consulted with GMBA. (click)GMBA is endorsed by Diversitas, just as MRI is endorsed by IGBP and IHDP. (click) MRI has begun consulting more frequently with WCRP, especially with respect to Climate and the Cyrosphere. It may make sense to seek a more formal endorsement by WCRP: after you see this presentation we would be interested in your thoughts.
- Some of you may be familiar with the Global Mountain Biodiversity Assessment, also looked in Switzerland at the University of Basel and headed by. Christian Körner. (click) GMBA and MRI are sister programs: whenever MRI encounters issues related to biodiversity it consulted with GMBA. (click)GMBA is endorsed by Diversitas, just as MRI is endorsed by IGBP and IHDP. (click) MRI has begun consulting more frequently with WCRP, especially with respect to Climate and the Cyrosphere. It may make sense to seek a more formal endorsement by WCRP: after you see this presentation we would be interested in your thoughts.
- I don’t like to hide the take-home lessons of a talk: here are the reasons why mountains are important to us.
- water supply, water power, water as hazard forests protect from avalanches, vegetation in general reduces the incidence of slope failure traditional mtn natural resources especially pasture and wood
- Now I would like to focus a bit more of the role of mountains in the water cycle and water supply. Here you see the intersection of a global precipitation data set with a global topographic dataset which divides the world between flat terrain and mountainous terrain. Average rainfall per year is globablly 15% higher over mountainous terrain than over flat terrain. This pattern is same regionally except in South America.
- I do not have time to take you through all the important values provided by mountains and then to show you how global change may affect these values. I will however so do for one or two key values. During the International Year of the Mountain, mountain were correctly touted as the “watertowers of the planet”. We have recently been able to locate and quantify more precisely the contributions of mountains to the global water supply. Viviroli and Weingarnter of the University of Bern looked at the proportion of flow in different river systems that is due to discharge from mountains. They classified river basins into four classes. IN the first class are rivers in which essentially all of the flow is attributable to discharge from mountains. This class includes some major world rivers: The Colorado in the western North America, the Amu-Darya in Central Asia and the Nile in Africa. IN the second set, discharge from mountains accounts for from 50 - 85 percent of annual discharge, and during periods of low water, mountain discharge accounts for all the flow in the river. This class includes the rivers in Mesopotamia, the Indus in South Asia, the Senegal and the Niger in Africa. Even in the third class, which includes the Rhine in Europe and the Columbia in North American, mountains contribute between 30 and 60 percent of the total flow, in many cases nearly double that of the area occupied by the mountains within the watershed. At a global level, and outside of the tropics mountains generate nearly double the amount of water that one would expect based on the area they occupy within the watershed.
- Here is a terrible example of the tendency of things high on mtns to find their was to the bottom, in this case, in a catastrophic fashion. This is Huascaran in the Cordillera Blanca of Peru. Note once again that nival zone. An earthquake (not uncommon in high mountains) shook loose part of the summit glacier on Huascaran in 1970, which then swepted over the town of Yunguy, killing 20000 people.
- Mountain forests and soils also provide carbon sequestration, biodiversity in both plant and animal kingdom, and finally they provide opportunities for recreation and tourism which it turns creates jobs and trade.
- So I have just reviewed why mountains are important. I would like to spend a few minutes speaking to why mountains (as distinct from flat lands) are interesting from a scientific perspective. Here I would like to emphasize three aspects or correlates of verticality. Because mountain stick up and because the atmosphere has such a pronounced lapse rate and because mtn create aspect, the physical environment of mtns is incredibly diverse, yielding in turn a wide range of habitats in a relatively small area. Because mtns stick up against the prevailing force of gravity, things higher up on mtns tend to find their way to the bottom of the mtn. This includes the material of the mtns themselves in the form of rockfalls, solid water in the form of avalanches, liquid water in the form of floods, or all of them mixed together. Finally, because mtns stick up they interfere with the circulation of the atmosphere in ways that flat lands cannot do.
- Here is a good example of the great range of environments from Kilimanjaro in East Africa. At least two things bear mentioning here. First the presence of snow, of stored solid water, on the summit of the mtn even at the equator. This reservoir of snow makes the mountains the third pole. Second, the juxtaposition of different habitats allows for exchanges between habitats that might not occur otherwise. This juxtaposition is much of what makes mtns interesting as habitat for humans.
- Finally, the mountains interfere with circulation, forcing air up. This uplift can create precipitation, and that precipitation can itself become convective. The processes andparameters involved in actually predicting what will happen as mtns force air upward are in fact many, so that a prediction of where, when and how much precipitation is surprisingly difficult, which means that predicting what will occur under a different climate is even harder.
- Because of these interesting features of mtns, one can imagine them as kind of “hotspots” of global change activity, when processes that otherwise occur in quite distant environments, such as the tundra and the equatorial forest, may occur quite close to each other, with gravity offering yet another way to mix the results together. I would like to emphasize four kinds of climate change impacts that we might nonetheless come to expect in mountain regions. These impacts derive from changes in that nival zone, where solid water is stored. We can also expect changes downslope where liguid water is more prevalant. Third, we should expect changes in the distribution and abundance of organisms. And finally we should expect changes in the disturbance regimes of these already quite dynamic environments.
- Climate change is now generally accepted by (almost) everybody. And climate change appears to be more pronounced in mountains, at least in the Alps. In Switzerland (approximately the same for the rest of the Alps), it is about twice more important than in the rest of the Northern Hemispere: + 1.35° for the 20th century instead of 0.66°. Is is very strong since 1975 with a decadal increase of 0.57°.
- A brief overview of the climate scenario used in the next slide - this is NOT an extreme scenario, but it ist pretty horrifying to see such temperature changes and such reductions of summer precipitation... This is what triggers the strong change in the wildfire regime seen in the next slide.
- Glacier recession and a rising snowline mean less of the winter’s precipitation enters into storage, and more enters the streams as runoff, with potential consequences for flooding.
- What to put here?
- What might a warmer climate do to snowpack? Here you see lines of equal duration of snowpack in a space defined by average precip and average temperatures. The future climate on the summit of the Säntis in Switzerland in the scenario investigated by Martin Beniston is three degrees warmer but also a little bit wetter. Nonetheless the duration of the snowpack at that altitude diminishes from 300 to 225 days. A similar projectio n at the village of Arosa ( an important ski resort) shows similar trends in temp and precip leading however to a halving on the duration of snow pack (from 150 days to 75 days). 100 DAYS OF snow is generally considered a lower threshold for a viable ski resort, so this scenario is quite threatening for this ski resort.
- So with such strong increases in temperature it is not surprising to find glaciers retreating, not just in the Alps, but in many mtn ranges of the world. A superposition of the photograph taken by Professor Finsterwalder in 1928 and by the German-Tajik expedition in 2002 shows a noticeable retreat in the tongue area of Muskulak glacier. The elevation change in the tongue area is about -30 m. ANIMATED SLIDE, the avi-file will be attached, having a size of 9 MB
- When reducing the glacier extent to zero as shown here, we still observe high spring runoff due to intense snowmelt, but runoff from glacier icemelt is reduced to zero, causing a sharp decline of summer runoff, now reduced to runoff from liquid precipitation only. The reduction of summer runoff is most pronounced for the Abramov glacier basin, as this basin has the highest degree of glaciation today (51 %) as compared to the other 2 basins.
- What will happen to water supply with climate change? This is clearly a central question for future research, but we have even now some preliminary ideas. Noah Knowles and Dan Cayan of Scripps examined the impact of warming alone (without any change in precipitation-a very conservative estimate) on water supply in California. California relies almost entirely on water flowing out of its mountains, with much of that stored in the form of the Sierra Nevada snow pack. The map on the left shows the current snow water equivalent during the month of April in the watershed feeding San Francisco Bay. The map on the right shows the percent reduction in SWE to be expected with a 1.6°C increase in temp. WArming temperature lead to much more winter precipitation in the form of rain and much less water storage in the form of snow. (click)These phenomena increases the winter runoff and with it the risk of flooding and difficulties for mulit-use management of reservoirs. In addition, this situation lowers the spring runoff and leads to much greater likelihood of salt water intrusion into the California delta with great water quality impacts on water supply.
- Climate change will affect other important values, such as energy production, through its influence on the water cycle. Mountain glaciers are among the most certain indicators of global change. Here you can see the changes in the extent of glaciers in the Bernese Oberland of Switzerland with the redlines showing the extent of the mountain glaciers in 1850 and the bluelines the extent in 1973. (click) This trend will certainly continue and will change the timing of water release from mountain watersheds. click- Recent work at the Swiss Federal Institute of Technology at Lausanne on what is now a glaciated basin used for hydropower generation indicates under future climates, as simulated by the PRUDENCE projects, precipitation over the basin will decline 8 percent. Click- However the nearly total loss of the glaciated surface will lead to a 36% reduction in the amount of power generated and click - a nearly 3 fold increase in vulnerability, which in this case is a measure of the inability to manage the system as planned.
- I will now show you a migration simulation for Lolium perenne, our previous winner species You will see the species migrating in elevation as temperature increases, with a maximum dispersal distance set to 40m for the species
- As changes are low, many attempts were made to predict future changes with mathematical models. These models are based on current distribution and climate, geomorphology, … As temperature is one of the main explaining variables for plant distribution, logically, like observed, plant will migrate higher in the future. A important research was done in the Western Swiss Alps, on the basis of more than 600 sampling plots, distributed from 400 to 3200 m. All the plants are not equal to the future climatic conditions (A1 + 6.2°C for the region considered). Lolium perenne, a lowland plant with a large ecology, will take advantage and will increase its distribution. Conversely, alpine plants like Saxifraga oppositifolia, will be limited in their migration by the mountain summits and are at high extinction risk.
- … ,for each mapping cell in the study area, the expected species turnover – a measure similar to the beta-diversity between two habitats, but here in time The high turnover rates observed at high elevation correspond to many species predicted as extinct by 2100, as also shown by the histogram of lost or gained area across all species Losers include for instance many alpine species Winners include more species from lower elevation
- If we now look specifically at the distribution of loser species classified by their dispersal ability, we see that a large third of species only disperse at a maximum distance of 4m This raises the question whether species will be able to migrate fast enough to keep pace with climate change Complement Pascal: Androsace et Gentiana: espèce boléochores, les graines sont petites et soufflées par le vent sur des distances très courtes, ne possédant aucune adaptation spéciale. Phleum: espèce cistométéorochore, les graines sont emportées par le vent grâce à des ailes peu portantes, la distance reste faible. Epilobium: espèce trichométéorochore, les graines sont emportées par le vent sur de grandes distances grâce aux poils qui améliorent fortement la portance Fragaria: espèce endochore, consommée par les animaux, la graine survit à la traversée du tube digestif et est déposée plus loin avec les excréments.
- When the dispersal distance of the species is not known, a sensitivity analyses can be conducted in MigClim by varying the dispersal distance We performed this for Lolium perenne under 5 dispersal distances and compared the results to the unlimited dispersal scenario Results show that, to keep pace with climate change, the species should migrate at a rate of 100m per year This might be eventually coped by this species, but is quite large for many other species! (remeber previous graph)
- A simulation for the landscape of the Gantertal (Valais, near Simplon). The landscape properties were collapsed into an elevational gradient. The top panel shows veg in equilibrium with current climate. Treeline is roughly where it should be, then one clearly sees the subalpine spruce forests and below the mixed forests. Under the changed climate (below, climate of the year 2080), treeline elevation would increase strongly IN THE VERY LONG TERM (the simulation shows veg in equilibrium with the climate of 2080, i.e. this would take several centuries to develop in reality!!), and forests characterized by very low biomass (and dominated by Scots pine) would develop there, where in the Valais many villages are found today. This would hamper protection from natural hazards (e.g. rockfall). The cause for the drastic changes below 1800 m a.s.l. is NOT in the direct effects of climate on tree population dynamics, but rather via the wildfire regime that changes from very few burns under current climate to a fire rotation of just a few decades, i.e. this landscape would burn entirely every few decades; hence also the reason for the dominance of the early-successional Scots pine.
- Une autre exemple provenant de la Californie regarde l’effet des changement climatiques sur les incendies de brousse, un problème qui se poser déjà en France méridionale et qui pourrait se généraliser dans l’avenir. Cet étude fournit non seulement les résultats intéréssants, surtout aux citoyens Californien mais aussi des lécons importantes, implicit aux études précedents pour tous qui cherchent à adapter”rationellement” leur services ou leur enterprises aux changements climatiques. De quoi disposaient les chercheurs qui leur a permis a conclure quoi que ça soit à ce sujet? D’abord ils avaient construit déjà une modèle des mécanismes de feu, comprennant les parametres physiques - la forme du combustible, sa teneur en humidité, la pente - qui est mise en route pars les conditions météorologiques. Ce modèle prédisaient la vitesse du feu et en conséquence, la superficie brulé à tout moment après l’ignition. Ce modèle est analogue au modèle hydrologique de Schäfli. Mais on lutte contre les incendies, et les chercheurs avaient aussi construit une autre modéle du fonctionnement de la Service des Forêts et Incendie en Californie- les équipes et équipements, les regles d’envoie, la taux de production de pare-feux en differents milieux. En effet, les chercheurs avaient une modéle qui produisaient des incendies d’une manière vraisembables sur toute la Californie et une autre modèle qui luttaient contres ces incendies. Le bilan s’exprimait en 1) nombres d’incendie qui echappent aux premiers efforts (et qui risquent alors de passer à la toute autre stade de “feu savage”) and 2) la superficie brulée par les incendies qui n’ont pas echappé. Ce modéle et ces indices de performance sont analogue au modèle et aux indices de l’exploitation hydroélectrique de Schäfli. Les chercheurs en Californie ont voulu savoir les indices de performance sous l’effet d’une climate de l’avenir. Comme Schäfli, il se sont servis des scénarios climatiques. Les scenarios sont donc la troisième morceau essentielle du puzzle. Je vous propose cette schüme comme point de repère pour tout effort visant l’adaptation au changement climatique: une modèle de la nature, une deuxieme modèle de l’exploitation humaine, tout les deux mise en marche sous l’influence climatique. Je disais que cette étude portait des résultats que je vous expose maintenant. Mais ces résultats ont eux aussi une lécon à nous apprendre: celle de la surprise. Lorsque les chercheurs ont fait tourner les trois modèles, ils ont trouvé des impacts assez severes oû le combustible a été en forme herbacée ou arbustive, mais aucune impacts en foret. Ces résultats s’explique par l’influence du vent: bien que beaucoup de parametres météorologique ont changé avec deux fois le teneur en dioxyde de carbone, le vent emporte sur les autres en ce qui regarde le comportement des incendies. Donc, une principle se fait voir: l’identité des variables climatiques importante pour la mise à point d’une stratégie d’adaptation est en fonction de la branche en question. Donc, avant de franchir la prochaine étape, qui consistera à dresser une liste des impacts dont on doit s’inquieter en région montagneuse, je veut sousligner la schema de trois modèles et le principe de la surprise, autrement dite, la nécessite d’études specifiques à chaque branche comme grille de lecture pour les suivants.
- Une autre exemple provenant de la Californie regarde l’effet des changement climatiques sur les incendies de brousse, un problème qui se poser déjà en France méridionale et qui pourrait se généraliser dans l’avenir. Cet étude fournit non seulement les résultats intéréssants, surtout aux citoyens Californien mais aussi des lécons importantes, implicit aux études précedents pour tous qui cherchent à adapter”rationellement” leur services ou leur enterprises aux changements climatiques. De quoi disposaient les chercheurs qui leur a permis a conclure quoi que ça soit à ce sujet? D’abord ils avaient construit déjà une modèle des mécanismes de feu, comprennant les parametres physiques - la forme du combustible, sa teneur en humidité, la pente - qui est mise en route pars les conditions météorologiques. Ce modèle prédisaient la vitesse du feu et en conséquence, la superficie brulé à tout moment après l’ignition. Ce modèle est analogue au modèle hydrologique de Schäfli. Mais on lutte contre les incendies, et les chercheurs avaient aussi construit une autre modéle du fonctionnement de la Service des Forêts et Incendie en Californie- les équipes et équipements, les regles d’envoie, la taux de production de pare-feux en differents milieux. En effet, les chercheurs avaient une modéle qui produisaient des incendies d’une manière vraisembables sur toute la Californie et une autre modèle qui luttaient contres ces incendies. Le bilan s’exprimait en 1) nombres d’incendie qui echappent aux premiers efforts (et qui risquent alors de passer à la toute autre stade de “feu savage”) and 2) la superficie brulée par les incendies qui n’ont pas echappé. Ce modéle et ces indices de performance sont analogue au modèle et aux indices de l’exploitation hydroélectrique de Schäfli. Les chercheurs en Californie ont voulu savoir les indices de performance sous l’effet d’une climate de l’avenir. Comme Schäfli, il se sont servis des scénarios climatiques. Les scenarios sont donc la troisième morceau essentielle du puzzle. Je vous propose cette schüme comme point de repère pour tout effort visant l’adaptation au changement climatique: une modèle de la nature, une deuxieme modèle de l’exploitation humaine, tout les deux mise en marche sous l’influence climatique. Je disais que cette étude portait des résultats que je vous expose maintenant. Mais ces résultats ont eux aussi une lécon à nous apprendre: celle de la surprise. Lorsque les chercheurs ont fait tourner les trois modèles, ils ont trouvé des impacts assez severes oû le combustible a été en forme herbacée ou arbustive, mais aucune impacts en foret. Ces résultats s’explique par l’influence du vent: bien que beaucoup de parametres météorologique ont changé avec deux fois le teneur en dioxyde de carbone, le vent emporte sur les autres en ce qui regarde le comportement des incendies. Donc, une principle se fait voir: l’identité des variables climatiques importante pour la mise à point d’une stratégie d’adaptation est en fonction de la branche en question. Donc, avant de franchir la prochaine étape, qui consistera à dresser une liste des impacts dont on doit s’inquieter en région montagneuse, je veut sousligner la schema de trois modèles et le principe de la surprise, autrement dite, la nécessite d’études specifiques à chaque branche comme grille de lecture pour les suivants.
- Specifically, the MRI used this diagram taken from the Global Land Project Science Plan as a framework by which to link together disciplinary studies. It is worth examining this figure more closely. On the outside we see the earth system, those planetary systems such as the atmosphere, the oceans but also the global market that establish the context with which we live. Embedded within the earth system are land systems, which are themselves compose of social systems (on the left) and ecological systems (on the right). These two systems are in constant interaction through what the GLP termed “land use and management” but which I generalize to “resource use and management”. Via resource use and management, social systems apply practices to ecological systems and receive from them ecosystem goods and services. The Global Land Project saw three major research themes with this scheme. The first, shown with green arrows, involves the dynamics of land land systems. The second, shown with red arrows, involves the consequences of land system change. And finally, the third, shown with blue arrows, involves resource sustainability. Each of these themes contains within it a set of key questions to which I will turn next.
- The GLP analytical scheme thus draws together a wide range of biogeophysical and social disciplines through a compelling rhetoric of whole system function. The GLP scheme is on the other hand spatially undefined. The elements within it certainly exist within space but it is not obvious a priori what spatial scales are relevant. The diagram could conceivably applied to one farmstead or to the entire Third Pole. In order to actually implement this scheme, we will need to how this system description actually manifests within geographic space.
- The GLP analytical scheme thus draws together a wide range of biogeophysical and social disciplines through a compelling rhetoric of whole system function. The GLP scheme is on the other hand spatially undefined. The elements within it certainly exist within space but it is not obvious a priori what spatial scales are relevant. The diagram could conceivably applied to one farmstead or to the entire Third Pole. In order to actually implement this scheme, we will need to how this system description actually manifests within geographic space.
- The GLP analytical scheme thus draws together a wide range of biogeophysical and social disciplines through a compelling rhetoric of whole system function. The GLP scheme is on the other hand spatially undefined. The elements within it certainly exist within space but it is not obvious a priori what spatial scales are relevant. The diagram could conceivably applied to one farmstead or to the entire Third Pole. In order to actually implement this scheme, we will need to how this system description actually manifests within geographic space.
- Over the last three decades GIS and remotely sensed data have allowed us to to obtain not just representative , but rather complete information about the surface of the earth. In addition, it has supported the development of spatial models for geographic variables that are difficult to measure. If the GLP analytical scheme is one way to characterize the entire land system, then so to is GIS. These two approaches use different vocbularies but are in fact referring to the same object. For the remainder of the time I would like to examine the proposition that one can express the systems approach of the GLP using the spatial coverages and models of GIS.
- Over the last three decades GIS and remotely sensed data have allowed us to to obtain not just representative , but rather complete information about the surface of the earth. In addition, it has supported the development of spatial models for geographic variables that are difficult to measure. If the GLP analytical scheme is one way to characterize the entire land system, then so to is GIS. These two approaches use different vocbularies but are in fact referring to the same object. For the remainder of the time I would like to examine the proposition that one can express the systems approach of the GLP using the spatial coverages and models of GIS.
- Thus, while it may be plausible to imagine that we can capture biophysical characteristics of the Third Pole in the form of wall-to-wall layers involving climate, vegetation and hydrology, it may not be so easy to imagine a analogous set of “social system” layers. At the very least we will need to understand that there are a variety of inter-related economies within the Third Pole. These economies may be best understood in terms of sub-regions or perhaps we need to imagine them as discrete kinds of enterprises co-existing nonetheless in the same larger space.