Interesting theory except, as others have pointed out, the Little Ice Age started perhaps 2 centuries before Columbus. The North Atlantic ice pack was growing by 1250. In 1315 the European climate changed permanently for the worse with with heavy rainfall and a permanent drop in temperatures. The deepest part of the Little Ice Age occurred with the Maunder Minimum where sunspots virtually disappeared (1645-1715). Unfortunately, there were no sunspot observations for the 13th and 14th centuries to to show whether the start of the Little Ice Age occurred with a solar minimum.
You're confusing the end of the Medieval Warm Period with the start of the Little Ice Age.
During the Medieval Warm Period from 950-1250 sea ice was temporarily reduced, allowing the colonization of Greenland. This is not necessarily related to the Little Ice Age from 1550-1850.
It's really a matter of deciding when is the start of the Little Ice Age. http://en.wikipedia.org/wiki/Little_Ice_Age Some put it at the end of the medieval warn period, others hundreds of years later. I favor 1315, because over the period of a few years the climate of Europe tanked for hundreds of years. Of course a 1315 date argues for the cause being a long solar minimum and not reforestation.
It's really just a matter of basic honesty to admit the consensus dating (1550-) up front. The 11 critical comments you're following from the linked article all fail to do this.
