Is it possible for a future ice age?

In quick summary, if enough cold, fresh water coming from the melting polar ice caps and the melting glaciers of Greenland flows into the northern Atlantic, it will shut down the Gulf Stream, which keeps Europe and northeastern North America warm (http://www.baltimorechronicle.com/feb04_IceAge.html). The worst-case scenario would be a full-blown return of the last ice age--in a period as short as two to three years from its onset; and the mid-case scenario would be a period like the "little ice age" of a few centuries ago that disrupted worldwide weather patterns leading to extremely harsh winters, droughts, worldwide desertification, crop failures, and wars around the world ( http://www.baltimorechronicle.com/feb04_IceAge.html). Showing graphs that proved the natural periodic comings and goings of ice ages and interglacial warm times like the one we now live in, they pointed to dramatic climatic spikes that occurred when world temperatures rose to a certain level (http://www.freerepublic.com/forum/a3ab8599422eb.htm). These spikes caused the world climate to bounce between very cold and very warm, then disappeared as the planet went into another long ice age ( http://www.freerepublic.com/forum/a3ab8599422eb.htm).