Climatic Change anthropologically caused or not?

There have been substantial climatic changes throughout the history of Earth, for example since the last Ice Age until the present day. Drill core analyses show that average temperatures have increased much more rapidly over the last few decades than in the previous thousand years.

ref. http://www.bmu.de/files/bilder/allgemein/image/pjpeg/bild_klima_ipcc.jpg

People speak about man´s made climatic change, especially caused by the output of Greenhouse gases. Also landscape have been changed through forest clearance, drainage of marshes, etc.. The climatic happening is a complex procedure and climate by definition means the average temperature and precipitation of many years. Research predicts that apart from a rise of global temperatures, that there will be an increase of short therm weather extremes and the increase of storms. For more information about climatic change see the web page of the Intergovernmental panel on Climate CHANGE (IPCC)
• http://www.ipcc.ch

Klaus Töpfer, Director of the UN environmental program, says that all of the signs shows that these extreme weather conditions demonstrate, that we already are in the middle of a climatic change.
• http://www.unep.org

An interesting and disputed theory to the Earth system and climatic change is the one by James Lovelock, who developed the Gaia theory at the beginnings of the 70s. According to his theory the earth is a kind of complex organism, whose buffer and feedback mechanisms hold the earth in an optimal temperature range, with a certain composition of the atmosphere and a certain composition of salt content of the oceans.
More about the Gaia theory & Daisy World see on the website of
• James Lovelock

In the Sierra Nevada the effects of climate change have already become visible: Nearly the complete melting of the ice masses in the summer and an increase of the temperatures over the last years. The efforts to protect the fauna and flora, which only can live under the special climatic conditions of the Sierra Nevada appear to be difficult or almost impossible due to this global development
• Articulo sobre este téma & Web Page of PN Sierra Nevada