by architek, Fri Mar 20, 2009 at 06:29:22 AM EDT
Scientists are predicting global temperature rises of at least four degrees Centigrade over the 21st century. Such changes are unprecedented in recorded human history, but they have happened before. A picture has recently emerged of the implications for human life and its not a pretty picture.
For example, a massive flooding trigger which apparently has happened repeatedly in the prehistoric past is the periodic collapse of the Ross Ice Shelf in Antarctica.
The implications of a collapse on coastal areas and flood insurance programs (typical insurance exempts all catastrophic events from coverage) would be devastating. For example, rapid rises in sea levels can trigger "Noah's Flood" like events as large basins at low elevations fill with water. Areas like the large parts of the US Southwest, Southeast/ East Coast and central California have been underwater in the past.
Also, increased temperatures could render large areas too hot and dry to support plant life, trigering mass starvation and presumably, migrations of those affluent enough to travel. As much as 50% of the Earths dry surface could become uninhabitable. This might be offset somewhat by areas of the Arctic becoming cultivatable, but the liberation of large amounts of methane locked in deposits on the sea bottom could accelerate global warming rapidly.
The Ross Ice Shelf, a massive piece of ice the size of France, could break off without warning causing a dramatic rise in sea levels, warn New Zealand scientists working in Antarctica."