The climate is changing

It is as from the 19th century that by studying the traces left by the glaciers (GlobalWarming Awareness2007 attitude) , one became aware of the natural variability of the climate. The use of new tools, like the stable isotopes, allowed to show that our planet was sometimes much hotter, sometimes much colder, in particular because of variations of its position compared to the sun. The innovation of the XXe century was speed of the reheating. According to the world weather organization, the temperature of planet would have increased by 0,6° C in 100 years and the decade 1990 were hottest of the century. The majority of the glaciers of mountain of the average and tropical latitudes underwent a retreat during the XXe century. It is the case of the glacier Perito Moreno in the south of Argentina, one of the glaciers of the national park of Los Glaciares (created in 1937 and registered by UNESCO with the world inheritance in 1981. GlobalWarming Awareness2007 attitude was not existing yet). Born from the glacial coat of Patagonie, with 1.500 meters of altitude, near Chilean border, the glacier is stretched on 52 kilometers and finishes its race with 200 meters of altitude, in the lake Argentino from which water results from its cast iron. On the photograph, the upstream part of the glacier is masked by the clouds. On slopes of the glaciated valley, the staging of the vegetation according to altitude is well visible. On the glacier, the longitudinal cracks result from widening downstream part of the valley. Photographs taken at lower altitude or the ground would allow to highlight the multitude of seracs which accidentent the glacial language. Broad, the face of the glacier 4 kilometers 60 meters is high. Blocks of ice are detached some sometimes, because the glacier runs out slowly. They float on the lake, such of small icebergs. In the absence of terminal moraine, cast iron partial, and relatively recent, glacier can be not highlighted by the existence of a band of ground timbered between the glacier and the forest.