References / Sources

Bintz Pierre, Bocquet Aimé, Borel Jean-Luc, Olive Philippe. Tableau diachronique de l’Holocène et du Tardiglaciaire dans les Alpes du Nord et leur piémont. In: Bulletin de la Société préhistorique française. 1989, tome 86, N. 2. pp. 51-60. (November2011)

Les Glaciers à l’épreuve du climat, IRD Editions - Editions Belin, 2007. (October 2011)

Academy of grenoble (2011)
Mountain vegetation http://www.crdp.ac-grenoble.fr/cfm/textes/paysages3.pdf (October2011)

Alparc
protected areas http://fr.alparc.org/les-espaces-proteges/les-epa-en-chiffres (November 2011)


Archives ouvertes
Jeanne Baudin thesis on "Observed changes in mountain vegetation of the Alps during the XXth century - Role of climate and land-use changes" (2010) http://hal.archives-ouvertes.fr/docs/00/59/21/44/PDF/Manuscrit_thA_se_Jeanne_Bodin.pdf (October 2011)

Daylimotion / maxiscience (January 2009)
Video on Climate change in the Alps http://www.maxisciences.com/glacier/recul-des-glaciers-un-reportage-sur-les-consequences-du-changement-climatique_art642.html


ENS Lyon
Milankovic cycles http://planet-terre.ens-lyon.fr/planetterre/XML/db/planetterre/metadata/LOM-milankovitch-2005-09-27.xml (December 2011)


Geos 3000
Glaciers risks http://geos3000.free.fr/glacier_risk.htm (October 2011)

Glaciers climat (2004)
Milankovic cycles http://www.glaciers-climat.fr/Glaciations_1/Periodes_glaciaires.html (October 2011)
Causes of glaciations http://www.glaciers-climat.com/les-causes-des-glaciations.html (October 2011)

Ina (2010)
Video on climate cycles http://www.ina.fr/sciences-et-techniques/sciences-humaines/video/CPD10001738/extrait-n3-cycles-climatiques.fr.html  (December 2011)


Jean luc Voisin
Presentation on glaciation http://jeanlucvoisin.free.fr/pdfcours/Les%20glaciations.pdf (November 2011)

La cliamatologie (Climatology)
Climate Forecast and global warming http://la.climatologie.free.fr/rechauffement/rechauffement4.htm (October 2011)

Notre planète (2001-2011)
Several articles on the Alps http://www.notre-planete.info/actualites (October 2011)

Partenariat de la montagne (2008)
Threatened species http://www.partenariatmontagne.org/issues/climate.html (October 2011)

Paysages glaciaires/ glacial landscapes
Quaternary and glaciation http://paysagesglaciaires.net/site_source/Pages_2/2_Glaciations_quaternaires.html (November 2011)

Unifr (Mountain geomorphology)
Permafrost  http://www.unifr.ch/geoscience/geographie/ssgmfiches/pergelisol/3109.php (October 2011)

Wikipedia (2011)
Glaciation and consequences http://fr.wikipedia.org/wiki/Glaciation#Les_cons.C3.A9quences_d.27une_glaciation (October 2011)
Glacier retreat http://fr.wikipedia.org/wiki/Recul_des_glaciers_depuis_1850 (October2011)
Grésivaudan valley http://fr.wikipedia.org/wiki/Gr%C3%A9sivaudan (November2011)
Milankovic cycles http://fr.wikipedia.org/wiki/param%c3%a8tres_de_milankovi%c4%87 (December 2011)

Youtube

http://www.youtube.com/watch?v=-p4CALvWjd0&feature=player_embedded
http://www.youtube.com/watch?v=5hr9QXqVMvg
http://www.youtube.com/watch?v=KVP29fHgMUM&feature=BFa&list=PLAB92F34D671CE2A7&lf=results_main

Conclusion

Conclusion of the blog

http://www.youtube.com/watch?v=KVP29fHgMUM&feature=BFa&list=PLAB92F34D671CE2A7&lf=results_main

Would those changes be a a question of cycles?

According to Milankovic, climate change would be due to three main astronomical factors.
Those are the orbital shape, the ellipse formed by the Earth's orbit is more or less offset by the laws of the attraction of the planets with each other (Newton). the eccentricity varies from 0005 to 0058. This component varies over a period of 413,000 years and implications for the aphelion and perihelion.

On the right, maximum eccentricity, on the left minimum

(Wikipedia,  2011)

The Axial tilt (obliquity)  can vary from 22.1 24.2 ° in a cycle of about 41,000 years. Differences in tilt affect the amount of solar radiation received on land in summer and winter will be greater the tilt, the greater will be marked seasons (hot summers, cold winters) and vice versa. However, these changes are mainly felt at the poles because the equator where the obliquity has little influence, only the intensity of wet and dry seasons vary.
 Variation of earth obliquity (wikipedia,2011)

The apsidal precession :During its rotation on itself, the earth is subject to the pull of the moon (nudation, tides) and the sun. Indeed, because of its "equatorial bulge", the earth does not turn itself on steadily but as a top. This has an influence on the indication of the terrestrial North Pole (a Usrae Minoris for the moment). During the rotation the "top" of the top will form a circle from the north celestial pole. the north-south axis is therefore a complete circle in 25,760 years.
the consequences are not specifically climate but it affects the precession of the equinoxes ie astronomically, winter is not always on December 21 and the astronomical seasons vary.

Precessions and seasons (Wikipedia, 2011)

Those factors have influences on climate when combined. The main influences are  the amount of solar radIation on earth, the temperature of ocean and continents and hemisphere because of the albedo and glacial cycles as well.

 Indeed glacial cycles are directly influenced by astronomical forcing. Each glacial period interspersed by warming period since. last 4.5 billion years have been throught by seven ice ages even cut into warming period and ice ages.

Ice ages and warming period since the earth creation (Glaciers-climat)

So, this raises the question of liability with respect to climate change, those that occurred in the past and those we are currently experiencing. In my opinion human beings are mainly responsible of current climate changes trying to control and utilize nature at the maximum. First recordedclimate change have indeed been observed in the late würm and early holocene period. As we seen before it was the start of anthropocene and it never stopped since then. Although natural cycle have imporant consequences, human beings aggravte them and the Alps and other sensitive areas could change irreversibly in the comming decades.

Global warming and ski resorts

 

Due to current global warming, ski resorts are endangered and with it all the winter tourism industry. Indeed, ski season are becoming shorter and shorter and snow falls lower and lower. Ski resorts above 1800m could be saved for a while but low altitude resorts (below 1500- 1600m) are directly touched by climate change. Last year some of them had to close a month earlier because of the lack of snow and warm temperature   Ski resorts have to face with this climate change offering other activities in ski resorts like hiking, sledge, etc.
However, there is a huge paradox about this purpose. Ski resorts are endangered by global warming but they also contribute to global warming and climate change with tourism. Tourism and ski industry are an ecological disaster for the Alps and its resources. Tourism pumps an incredible amount of water for snow canons, water reservoirs and tourism needs.
Ski resorts and the Alps in general can't live without tourism income, it's the major activity in this area so they have to mitigate the effects of climate change. This is the reason why some actors of states, NGOs and tourism try to commit against climate change effects. For example, states have created parks and protected areas. NGOs built some projects as the Alpine convention, ALPARC, etc and the Group Pierre et vacances- center parc which is the biggest tourism company in Europe, they have set up a whole system of eco friendly actions to limit their impact on the environment.
Obviously, all those actions are almost useless compared to the pollution tourism creates and the pollution doesn't care about boundaries of parks or countries. Climate will continue to change whatever we do and we need to figure out the future of ski resort, the post ski and post tourism futur for the Alps.

Picure; Val Thorens in November 2011, Opening date (Rtl.fr)

Reference: http://geofac.over-blog.com/30-index.html://

The Holocene period, Climax and anthropocene

After experiencing a near-polar atmosphere,  global warming is setting up in the Alps about 10 000 years ago,  this is the Holocene or climatic optimum. this is the reclaiming plant, plants migrate from their meridional shelters to territories abandoned by ice. This is also the period where we find the first traces of human activities. The settlement of men begins to take precedence over nature. they exploit the land for agricultural purposes but also for the frame.
The Holocene  known to be stable also had some climatic variations period . According to a report from Bintz et al (1989) this period is subdivised in some others ones.

• Preboreal (10000 - 9000 BP): the transition from late glacial warming and this results in regression of herbaceous and shrub steppe taxa in favor of Betula and Pinus. Changes in vegetation during the Preboreal emphasizes improving the climate. Rising temperatures, entails a substantial increase in forest communities. Although any estimate altitudinal be difficult, it seems that the upper limit of the forest has puatteindre 1900 m in the area of intra-Alpine.
• Boreal (9000 - 8000 BP): The Boreal is the period of the peak of Corylus (hazel), which extends roughly in the floors and hill and mountain, quickly eliminating Pinus and Betula.The hazels are in competition witha "mixed oak" in which Ulmus (elm) plays an important role, rising to 1500 m above sea level. Other elements of the package deciduous Quercus and Tilia (lime) are well represented, Acer (maple) is rare, Fraxinus (ash) extends gradually. The appearance of Hedera (ivy) and Viscum (mistletoe) may reflect relatively high temperatures. In the Montane level , the Hazelnut trees still dominate, constituting a narrow belt between the Quercetum mixtum and pine forests. Groups of subalpine Pinus uncinata (pin hook), Pinus cembra (arolla pine) and Benda to develop expense of shrubland in the massive internal, the tree probably reached at the end of this period, 2 100 meters. The margins have a southern vegetation dynamics close to that of the Southern Alps. Corylus is very discreet, Quercus, Ulmus and Tilia are still poorly represented.
• Atlantic (8000 - 4700 BP):The Atlantic is a time of profound changes in the vegetation cover in the Northern Alps. The Quercetum mixtum wins in  collinean stage . Its high percentages are due mainly to the development of Fraxinus, but also Tilia and Ulmus, Acer achieved its highest values. Then, in mid- old Atlantic  Abies huge extends  in the Montane stage and has a significant wealth  on all the North Alps.The Pine Forest shows a remarkable altitudinal range, from 1 000 to 2 000 m, pushing below the "mixed oak" and spreading largely on the slopes at the expense of groups alticola Pins. The sharp increase causes a sharp rise in the upper limit. In Oisans, Abies colonized slopes above 2100m. If the massive western wetlands, Pine Forest is fast in the dry inland valleys, this training is confined to a narrow strip in shady, and the pine forests continue to dominate the intra-Alpine mountain scenery. Other distinctive features of the Atlantic are the strong increase of Alnus glutinosalincana in wetlands, the place not negligible of Taxus in the vegetation of Piemont Dauphinois and the Vercors, the expansion of Pinus cembra in the subalpine and the presence of fairly regular Alnus viridis (green alder) in altitude sites. Finally, in the external massifs. Fagus extends gradually from the 6th millennium BP. With the Neolithic, the first demonstrations of farming activities occur in the pollen diagrams. The oldest clearings, along with cereal crops, have been recognized Pluvis (210 m), Francine(288 m), Charavines-les-Bathers (495 m), Choranche(500 m), Saint-Thibaud-de-Couz (500 m) and Luitel Col (1250 m).
• Subboreal (4700 - 2700 BP): From the  end of the Atlantic , around 5000 BP, Fagus begins a continuous increase in the higher collinean and lower montane, between 400 and 1200m, . However, this species has never transgress the limits of current area that is both the south. In the Mountane stage, beech could be associated to the fir tree, it is also possible that the distributionof these two species resulted from the influence of local  and ecological factors. Abies colonizing cool, moist slopes, and Fagus hot and dry slopes. The competition factor between different tree species only may explain the regression of hardwood forests. At low altitude,elm, ash and linden and oak disappear,may be promoted by clearing the  final Neolithic and and the Bronze Age, becomes the constitutional main groups killing hill and forest.
  In the subalpine zone of massive internal Alnus viridis, Larix and Picea, which appeared in the Atlantic are quite regularly but moderately represented. The moors and montane grasslands are
  colonized by Arolles. In Oisans, for against the Pinus cembra pollen is rare. The upper limit
  Procedure of the forest rises over this chronozone, In Maurienne, it probably reached2 400-2 500 m, well above the stage. Clearing of the Neolithic Age and the Bronze, more or less marked depending on the site,reflect the growing influence of man oncover, the intensity of settlement and the colonization of territories with little or no popular before.
• Subatlantic (2700 BP to Present):Temporary colonization by the tree orBeech at the top of hill and at the  transition Subboreal-subatlantic, report wetter conditions and cooler. Moreover,  many authors have hypothesized aclimatic deterioration at the end of the Bronze Age.Until then mainly determined by the great migrations of arboréenes species that  punctuate the forest dynamics and postglacial climate change, the composition and physiognomy of the plant cover in the Northern Alps  changes depending on the needs of people. The evolution of the vegetation is deeplyupset, at all altitudes, by clearing, agricultural and pastoral practices,logging and the introduction of new species.  In collinean area ,  succesive clarifications  of oak woods have indirectly but undoubtedly favored the development of hornbeam, Walnut and Chestnut. Their introduction dates, traditionally reported to the Roman times, are not known. The major eventis the expansion of Picea in the Subalpine basis, to the detriment of the Pine Forest and Arolles, Pins hook and larches.The extension of this came later - around 2000 BP in the central area at the medieval time in Oisan- was probably favored by the increasing human pressure. A high altitude, a consequence of  the cembra degradation   and other groups  in subalpine forest , the secondary stands of Larix, moors in Ericaceae or Juniperus (Juniper), of Alnus viridis bush to spread on surfaces deforested. Finally, the chronology of the various episodes of the Little Ice Age in the MassifDes Ecrins was established on the basis of a comparison of dendroclimatic and pollen data.

References :http://www.persee.fr/web/revues/home/prescript/article/bspf_0249 7638_1989_num_86_2_9362
Consulté le 16 novembre 2011

The Alps at the time of ice

"Over the past millennia and centuries , glaciers have continued to evolve, changing volume, shape, color, forward or backward. These changes, sometimes significant, are closely linked to climate fluctuations. In cold regions where they are preserved, the different layers of ice and snow a glacier component trap over time chemical and biological elements that deliver valuable information on the successive states of the atmosphere over a long period. Ice and glaciers and offers essential tools for scientists to reconstruct past climates and better understand the current warming of the planet." (Francou et Vincent, 2007)
The last major ice age began in the Alps at the end of quaternaire.About 70 000 years ago, begins the Würm glaciation, which reaches its maximum  25 000 years ago.
At that time, ice covered all the Alpine valleys. Indeed, the Mont Blanc glacier covered the whole Arve valley to Geneva, the Rhone Glacier in Switzerland reached then the gates of the city of Lyon (about 15 km, at the current airport) . The Rhone glacier was joined by some parts of the glacier Isère (Grenoble).

Mont Blanc valley  and the main glaciers during the Würm (Geo- Alpes, 2010)

This extreme development of Glaciers, particularly in France and Switzerland explained in part by the topography of this area of the Alps. The slopes are less steep and glacial cirqueswider. Ice has no problem extending into the valleys, forming a thick and solid layer.
In the "Research on the Ice Age and the former extension of glaciers of Mont Blanc from the Alps to the Jura" Charles Martin explains that during this period, temperatures in Geneva should have decreased by 4 or 5 ° C (from 10 to 5 degrees), this way and due to the altitudinal gradient (the air temperature decreases by 1 ° C every 188 meters) the eternal snow line being lowered then 2700 m to 1955 meters. The bottom of the glacier also be lowered by 750 meters and therefore reach the Swiss plain. This plus the fact that the glacier of Mont Blanc (glacier of the Arve) is located in an area large circuses explains the fact that the glacier have been able to reach the town of Geneva from Chamonix.
the ice age left its mark in the Alps and in particular in France in the Alps in the north. Glaciers are large "erosion machines" and deep valleys post coolers are formed after the retreat of the ice like the Grésivaudan valley (Albertville, Grenoble) which now forms a deep U-shaped valley.


Grésivaudan valley  from le Touvet ( Wikipedia, 2011)

The first result of glaciation of such importance is the decline in sea level (120 meters lower than today during the Würm). This lowering of sea level causes a decrease in the surface of the continental shelf (richest  lifezone). Furthermore, the thermal gradient becomes higher, this leads for each species to a trophic zone which decreases thus increasing the competition between species.
Phase of ice to survive, a species subject to too much cold for them, should descend to the plains  and find new ecologic shelters. They must do so especially since they are sensitive to cold, or survive in smaller populations and sometimes less dense in areas of refuge less affected by cold.
During the last ice age, it does not appear to have been much loss of overall species on the planet, but for species with low dispersal ability, the cold has caused the local extinction of many populations in metapopulations then existing, with the corollary reduction of genetic diversity in some groups, these effects "negative" for biodiversity can be mitigated by the dewatering of the continental shelves helped by lower sea levels. Thus there were new areas that have reconnected habitats almost disjoint (set out for birds and marine mammals and some species) during interglacial phases (eg the current France was reconnected to the current United Kingdom during the last ice age, allowing large mammals (including mammoths) to move from one area to another across the current floor of the Channel and the Strait of the Pas-de-Calais. the genetic consequences of climatic oscillations, and glaciations in particular, are important. (wikipedia, 2011)
The late glaciation period has deeply shaped the Alps as we know it today.