Climate changeClimate change is not just an environmental problem but it will direct affect the life of billion of people with the storm increasing, shifting of rainfall patterns, availability of water, productive land, marine fisheries, in few words, it has a paramount importance on the economy and on the lifestyle of our society.
Climate change is always occurring at all time scales and the Earth has so experienced a series of glaciations and warm periods in its 4.57 billion year history recording the traces in its landscapes. The geological record has become an important archive for understanding the range of natural variability in climate and the processes that cause climate change on decadal or longer time scales.
Combinations of proxy data are generally used to reconstruct records for past climate. Common proxies and their respective analytical methods include shelled microorganisms in deep marine or lacustrine sediment cores, ice cores, speleothems, coral reefs, tree rings, pollens, geological, geomorphological and paleontological observations.
Predictions of future climate change are subject to considerable uncertainty, for two main reasons: future factors that may influence climate such as emissions of greenhouse gases, volcanic eruptions, and changing solar activity are uncertain; and knowledge of how strongly the climate system responds to external influences, particularly increases in greenhouse gases, is incomplete (Hegerl and Russon, 2011).
But climates of the past, coupled with appropriate physical climate models and statistical modeling can provide potentially powerful information to reduce uncertainty in future climate predictions and evaluate the likelihood of climate change.
One of the major problems linked to the increasing global warming is progressive sea level rising, by thermal expansion of seawater and melting of land ice masses.
The availability of local long record of sea-level changes on land would be extremely useful for improving regional and global sea-level oscillation curves, to evaluate the local impact of sea level changes and it can help in constructing future regional climatic scenarios under the increasing condition of green-house gasses.
The Patagonia is the only continental landmass emerging along the mid to low-latitudes in the Southern Hemisphere, and this makes it an unique region of the world.
This represents a key area for understanding the role of the southern hemisphere in regulating climate during the last hundredts of thousand years.
From the Andes to Atlantic coast Patagonia preserves an impressive geological record of the glacial events and sea-level oscillations, both marine erosion forms (notches or shore platforms) and deposits. The Quaternary coastal deposits, often organised in spectacular successions of raised-beaches-ridges deposits containing an almost unexplored archive of past climate. These natural archives can offer precious informations on local relative sea-level changes, tectonic and glacioisostatic component, and fundamental information on past surface ocean conditions and, through the study of the continental deposit related to beach-ridge systems, information also on terrestrial climate.