The Vikings settled Greenland in around 1000 AD. They had a colony on Greenland until around 1500 AD. That is the basic history, so why is it so hard to determine why this period in Viking history was so prolific? Because the medieval warming period that stimulated the Viking's rise in prominence is no longer politically correct.
The medieval warming period is a time from approximately 950 AD to 1450 AD where temperatures in the northern hemisphere were notably warmer. Warmer as in the temperatures we are experiencing now. This period was followed by another period called the little ice age where temperatures fell for a few centuries, ending in the early 1800's.
Prior to 1998-ish, there was debate over the medieval warming period and the little ice age, but not out right war in the scientific community. Now there is war! Any argument that there were milder climate conditions between 950 and 1450 AD fires up a huge debate with near political mudslinging in the climatologic community. Then remember, the louder people protest, the higher the probability of a real news story.
Digging a little deeper, one may find that most scientific proxy data that supports the existence of the medieval warming period is missing from recent climatologic reports. The recent International Panel on Climate Change (IPCC) dismissed all evidence of the medieval warming period. Research by Dr. Lloyd Keigwin with the Woods Hole Oceanographic Institution (WHOI) published in 1996, implied that the medieval warming period not only happened, but also had global impact.
Dr. Keigwin's research was published in the peer reviewed journal Oceanus, a WHOI publication and funded by the National Oceanographic & Atmospheric Administration Climate Change Program. The research he made should have been included or at least mentioned in the IPCC report on climate change.
Other allegations by climate scientists are being made. One that I find particularly interesting is that heat island effect and other influences, are not considered on the individual weather stations used in determining average temperatures. The heat island effect is where local temperatures are higher due to reduced solar reflectivity. Walk barefoot on a black tar road and you will experience part of the heat island effect. This effect can cause temperatures in municipalities to be ten degrees above the ambient temperature.
While very few scientists dispute that some manmade climate change is occurring, the rate and impact are hot topics. So hot that some standard peer reviewers are not included. This is not a good thing, picking and chosing peer reviewers is too political to be good science practise.
