Chapitres
Notice
Present-Day Geomorphological Changes in Polar Regions
- document 1 document 2 document 3
- niveau 1 niveau 2 niveau 3
Descriptif
The landscape uniqueness of polar zone manifests itself in morphological traces of older glaciations and marine transgressions, areas of present-day glaciations, multi-year permafrost, multi-year snow covers, deglaciation processes variable in time and space and resulting in an expansion of ice-free 94 areas, multi-directional geosuccession, and finally in the various responses of the Arctic peoples to landscape changes and the growing human impact. The abrupt landscape changes taking place over a period shorter than the life span of a single generation can be due to a wide variety of natural causes, whether endogenous or exogenous, or to the increasing, multi-directed human activity. At present, however, their principal cause is believed to be climate change at a variety of spatial scales. The paper presents examples of contemporary changes of morphologic surfaces from all the territory of the Arctic and Antarctica. Among the most significant environmental changes noted in the polar regions, can be list the following:
• air temperatures frequently exceeding the hitherto absolute maxima,
• an increase in annual precipitation totals, first of all in the form of rain, also during the cold period,
• cold periods becoming milder and shorter,
• transitional periods becoming longer: spring coming earlier and autumn ending later,
• a decrease in the thickness, persistence and area of the sea-ice cover,
• an increase in the number of icebergs from intensively calving glaciers,
• an increase in the temperature and a decrease in the salinity and density of ocean waters; changes in the thermohaline circulation,
• an increase in the level of the world ocean,
• intense ablation and rapid recession of the majority of polar glaciers,
• a decrease in the area of nival covers,
• intensive thawing of multi-year permafrost, mainly in continental parts,
• changes in the water cycle manifested by an increase in the surface runoff in streams and a shortening of the period of freezing of streams and lakes,
• an increase in the area of some wetlands and a decrease in others,
• a northward shift of geoecological, including vegetation, zones,
• changes in the carbon cycle in the geoecosystems manifesting themselves in an increase in biogenic carbon dioxide and methane, and
• an increase in the frequency and magnitude of forest fires.
All those symptoms of climate change affect the terrestrial geoecosystems of polar regions to a greater or lesser degree. The ever-growing role of rock geoecosystems, crucially dependent on glacier and nival geoecosystems, results from intensive glacier recession and the melting of permafrost and snow covers. The polar research to date and scenarios of development of polar regions indicate that the polar landscapes have been undergoing rapid changes recently.
Dans la même collection
-
Comparison of Simulated Tree-Ring Cellulose d180 at the European Scale
DANIS Pierre-Alain
In order to investigate factors involved in the inter-annual variability of d180 in tree ring cellulose (d18OTRC), we simulated the d18OTRC from 1960 to 2001 over Europe. We used 1) simulated climate
-
Borehole Climatology and Model Simulations: Steps to Integrated Assessment
GONZALES ROUCO Jesus Felipe
Progress in understanding climate variability through the last millennium leans on simulation and reconstruction efforts. Exercises blending both approaches present a great potential for answering
-
Food demand, Productivity Growth and the Spatial Distribution of Land and Water use: A Global Model…
POPP Alexander
Nowadays, human society appropriates about one quarter of total net primary production of the terrestrial biosphere. Production of food, energy and materials, and the related use of land and water
-
Turning Hazards into Ressources? Climate Change, Floods and Coastal Wetlands in the Costa Brava (No…
SERRA-LLOBET Anna
According to the IPCC Fourth Assessment, one of the most vulnerable areas in Europe are coastal zones. This is due to sea level rise combined with increased risks from storms. Coastal wetlands, in
-
How to Foster the Economic and Societal Technical Solutions?
CALLONEC Gaël
The presentation will focus on the interplay between economic scenarios (based on energy demand and CO2 emission reduction) with long run-public policies. The French case will be discussed in more
-
Debate
DJéDJé Okoubi Franck Didier
MILLNER Antony
RAJ ARYAL Komal
FRAGNIèRE Augustin
The European Science Foundation (ESF) and the French Foundation of the Maison des Sciences de l’Homme (FMSH) (within the Entre-Sciences programme) have agreed to jointly develop a new conference
-
Climate Models: learning from the Past Long-Term Climate Variability
JOUSSAUME Sylvie
Projections of future climate change rely on global climate models. Such models simulate the dynamics and physics of the coupled atmosphere-ocean system and move towards models of the full Earth
-
Data-Model Fusion Approach in Global Change Research: Recent Development and Future Challenges
PENG Changhui
It is increasingly recognized that global change research requires methods and strategies for combing process models and data in systematic ways. This is leading to research towards the application of
-
The Largest Lakes and reservoirs of Russia as a Priority Water Ressource for Society
LEMESHKO Natalia
Global change for the last 25 years drives to important changes in hydrometeorological regime in different regions, reflecting water resources change of the larges reservoirs and lakes of Russia and
-
The Economics of the Climate/Development of the Gordian Knot; Beyond a Sound Pessimism
HOURCADE Jean-Charles
We will first suggest that costs of meeting ambitious climate targets capable to stabilize global warming below 2°C or 3°C temperature increase have been underestimated so far. The first reason is the
-
Debate
CALLONEC Gaël
DUPUIS Johann
THORON Sylvie
The European Science Foundation (ESF) and the French Foundation of the Maison des Sciences de l’Homme (FMSH) (within the Entre-Sciences programme) have agreed to jointly develop a new conference
-
IPCC Working Group I and III
JOUSSAUME Sylvie
The European Science Foundation (ESF) and the French Foundation of the Maison des Sciences de l’Homme (FMSH) (within the Entre-Sciences programme) have agreed to jointly develop a new conference
Sur le même thème
-
Géo-Rencontres 2024 / Les expériences valorisées dans le monde professionnel
LILLO Emma
ARAUJO Julie
HUART Florian
DUBREU Romain
BUQUET Damien
CHAZAL Laura
BORIE Mariane
Forum sur les métiers en géosciences organisé par les étudiants du CMI Ingénierie Géologique et Civile, Université de Bordeaux, 12 avril 2024
-
Géo-Rencontres 2024 / Compétences et acquis nécessaires pour entrer dans le monde du travail
BRINON Juliette
AMOLE Fili-Fenua
PRETOU Frédéric
CAMPET Hugo
LIéBAUX Albin
DE ALEMEIDA Marie-Lou
POIRIER Aymeric
DUFRENOY Audrey
Forum sur les métiers en géosciences organisé par les étudiants du CMI Ingénierie Géologique et Civile, Université de Bordeaux, 12 avril 2024
-
Géo-Rencontres 2024 / Variété des carrières via les formations de l'université
INGUIMBERT Diane
LACAZE Romane
LEMAITRE Laurie
CHAZAL Laura
MONTJEAN Pascal
POUDEVIGNE Jacques
PORTEFAIX Frédéric
Forum sur les métiers en géosciences organisé par les étudiants du CMI Ingénierie Géologique et Civile, Université de Bordeaux, 12 avril 2024
-
Géo-Rencontres 2024 / Présentation
LATASTE Jean-François
LAVIE Théo
Forum sur les métiers en géosciences organisé par les étudiants du CMI Ingénierie Géologique et Civile, Université de Bordeaux, 12 avril 2024
-
Tokyo, plus grande « ville » au monde : aménager et gouverner la démesure
LANGUILLON-AUSSEL Raphaël
Avec ses quelques trente-cinq millions d’habitants, Tokyo est la « ville » la plus peuplée au monde, et l’une des métropoles les plus riches. Cette présentation vise à décrire, analyser et expliquer,
-
L'approche par la dépense du PIB et les grandes fonctions macroéconomiques
MAVEYRAUD-TRICOIRE Samuel
L'approche par la dépense du PIB et les grandes fonctions macroéconomiques
-
-
-
-
Les déterminants de la demande agrégée
MAVEYRAUD-TRICOIRE Samuel
Les déterminants de la demande agrégée
-
La théorie du revenu permanent et la notion de richesse
MAVEYRAUD-TRICOIRE Samuel
La théorie du revenu permanent et la notion de richesse
-
Présentation du mécanisme du multiplicateur
MAVEYRAUD-TRICOIRE Samuel
Présentation du mécanisme du multiplicateur