Anyone who lives near one of the Great Lakes knows that summer cannot get started until all the ice melts. Temperatures away from the lakes are often much warmer in the spring because so much of the heat from the sun is absorbed by the melting ice. Once the ice is gone the temperature increases rapidly until the average temperature is only slightly lower than the surrounding area.
The same principle applies to global warming. Changes will at first be small, but if all the ice melts, the increase in temperature world wide will be dramatic. The first and most important sign of this happening will be the melting of nearly all the ice in the Arctic Ocean. If that happens, then warming temperatures in the North Atlantic could lead to the collapse of the Greenland ice sheet, and that would trigger events of Biblical proportions. The sudden shift of weight off Greenland and into the ocean basins would crack loose the earth's plates and produce a level of earthquake and volcanic activity far greater than anything any human being has ever experienced before. The resulting political and economic chaos will be even more catastrophic.
Now one might dismiss all this as mere speculation, but then again it was Jesus who told us of the events that would signal his immanent return. So along with earthquakes famines and plagues Jesus stated that “there will be signs in the sun and moon and stars, and upon the earth distress of nations bewildered by the roaring of sea and waves.” (Luke 21:25)
While one might wonder about these other events, the idea that nations would be distressed and bewildered by the sea is something that would only happen if sea level rises enough to inundate coastal areas around the world. If cities around the world are destroyed one after the other, nation will be distressed by their shear inability to cope with such an unprecedented level of destruction.
How likely it that any of this will happen? The models currently being employed by climate scientists point to an increase in sea level of 3 to 6 feet before the end of the century. However, if all the ice on Greenland were to melt the sea level would rise 22 feet. In any case, anything over 3 feet would be extremely destructive and anything over 6 feet would be apocalyptic.