The earth's continuous cyclic change

As I was perusing through a June 2010 edition of National Geographic, I came across two articles dealing with Greenland. The first article was of course about the disappearing glaciers of the island. It was the second article that really caught my attention, though.

It seems in A.D. 982 the Danish fugitive Eric the Red happened upon Greenland in his flight. In his Eureka moment, he returned to Iceland and convinced some of his countrymen to return with him and settle onto this new promised land.

The colony flourished for several centuries until about the year 1450 when it slipped into the pages of history. What happened? It seems around the year 1300, the climate turned colder (the "little ice age") and eventually drove the hardy Norsemen from the island. The ever changing climate, which made it possible to inhabit this island, once again changed to make it uninhabitable.

Perhaps amateur climatologists or con man Albert Gore Jr. might want to explain how man affected the climate then to cause this anomaly. It must have been all the smoke from burning peat for heat, for there are no trees to harvest. For you see, I do believe in global warming and global cooling and so forth and so on ad infinitum. It is a continuous cyclic change that causes this phenomenon. Man's impact upon nature seems to be trivial in these matters.

JAMES C. ROCHE, Jackson