Saturday, 2017-12-16, 7:21 PMMain | Registration | Login

Site menu

Site Resources

Video of the Month

Leadership

Concerns

Search

Print

Contact Us

Statistics


Total online: 1
Guests: 1
Users: 0
Glacials and Interglacials

GLACIALS AND INTERGLACIALS




 

 

Within the ice ages more temperate and more severe periods occur.  The colder periods are called GLACIAL PERIODS, the warmer periods INTERGLACIALS, such as the Eemian Stage.


Glacials are characterized by cooler and drier climates over most of the Earth and large land and sea ice masses extending outward from the poles.  Mountain glaciers in otherwise unglaciated areas extend to lower elevations due to a lower snow line. Sea levels drop due to the removal of large volumes of water above sea level in the icecaps.  There is evidence that ocean circulation patterns are disrupted by glaciations, also known as abrupt climate change.  The Earth has been in an interglacial period known as the Holocene for more than 11,000 years.  It was conventional wisdom that the typical interglacial period lasts about 12,000 years, however there has been some controversy regarding this.  For example, an article in Nature argues that the current interglacial might be most analogous to a previous interglacial that lasted 28,000 years.  Predicted changes in orbital forcing suggest that the glacial period would begin at least 50,000 years from now, even in absence of human-made global warming.  Moreover, anthropogenic forcing from increased greenhouse gases might outweigh orbital forcing for as long as intensive use of fossil fuels continues.  At a meeting of the American Geophysical Union on December 17, 2008, scientists detailed evidence in support of the controversial idea that the introduction of large-scale rice agriculture in Asia, coupled with extensive deforestation in Europe began to alter world climate by pumping significant amounts of greenhouse gases into the atmosphere over the last 1,000 years.  In turn, a warmer atmosphere heated the oceans making them much less efficient storehouses of carbon dioxide and reinforcing global warming, possible forestalling the onset of a new glacial age. 

 


Copyright gogreencanada © 2017 | Free web hostinguCoz