considering That the Vikings Were Able to Farm in Greenland for over?

Considering that the Vikings were able to farm in Greenland for over 400 years and finally left in the medieval ice age, how do global warming scientists explain it?

Details can be tricky. I assume you’re talking about how Viking settlements have been found under the ice, which indicate that ice was less than it is now, about 1000 years ago. It doesn’t actually prove that, it only proves that ice was less in some places, not overall, but lets assume for the sake of argument that Greenland ice volume was lower 1000 years ago than it is today. What does that tell us? The little ice age lasted over 100 years. By some estimates, a few hundred, from about 1300 to 1850. Even if you shorten that period, Earth underwent cold periods around 1650, 1770 and 1850. Little Ice Age - Wikipedia If we make a basic assumption that the Greenland ice sheet grew during the cold periods above and shrunk during the recent global warming, it had a few hundred years to grow and only a few decades to shrink. The acceleration of melting of Greenland's glacier has only been identified for 20 or 30 years. So in a sense, comparing centuries of ice growth to 20 or 30 years of recent ice melt isn’t a fair comparison. It’s not that surprising that ice would be melting now that formed during the little ice age. According to this article, Vikings settled on Greenland around 1000 and left around 1400. One of the world's biggest archaeological mysteries is melting away before our eyes This article suggests that the cold snap of the little ice age, which may have been quite severe on Greenland, a drop of several degrees over a few decades, lead to the departure of the Vikings. Cold Snap Drove Vikings From Greenland, Study Suggests “The researchers determined that the local temperatures plunged several degrees over the span of a few decades, a cold snap called the "Little Ice Age”’ and it gives a different time table, suggesting the Vikings began to suffer from cooling in Greenland much earlier, as early as 1100. “The cooling started around the year 1100, dropping 7 degrees Fahrenheit (4 degrees Celsius) in 80 years. The change could have shortened the crop growing season and increased sea-ice levels, making trade and sailing difficult. "Suddenly year after year, you go into this cooling trend, and the summers are getting shorter and colder and you can't make as much hay. You can imagine how that particular lifestyle may not be able to make it," D'Andrea said. The colder weather might have ousted the Norse from their settlements, which were set up in the 980s.” That article is interesting, because it suggests, based on ice core data, Greenland began to get colder as early as 1100 AD, which was during the Medieval Warm period, but after the warmest part of it, between 950 and 1100 AD. Medieval Warm Period - Wikipedia This suggests that ice on Greenland, or, to be more specific, South Western Greenland where the settlements were, may have begun to grow not long after 1100 AD and grown into the 19th century and only begun to shrunk in the late 20th and 21st century, so it had hundreds of years to advance and only a few decades to recede. With that in mind, it shouldn’t be all that surprising that ice still exists today that wasn’t there at 1100 AD. Note, that the article on the medieval warm period gives somewhat different dates, but generally the same information, with the Vikings shifting from farming to fishing and seal hunting over time, largely relying on fishing by about 1250 and the last known evidence of a settlement dated around 1412, though it was in part abandoned due to a falling in trade. Medieval Warm Period - Wikipedia Western Greenland is also an unusual area on the Earth because it’s climate is so strongly correlated with the Atlantic ocean and West Greenland current next to it. As the Baffin bay and North Atlantic loses salinity the current weakens and this can cool that entire region. Interestingly, ice melt elsewhere can lead to ice buildup across western Greenland. Let me be clear that I’m not saying that this is what happened, but it’s certainly plausible. Western Greenland is dependent on Atlantic temperatures and changes in ocean currents would affect it considerably. That’s why Greenland isn’t a great measuring stick for global temperature. It’s too driven by changes in ocean currents. On the Baffin bay and Younger dryas cooling.Figure 10. Currents in the North Atlantic and around Greenland. Note... What does sea level tell us.Different sites give different estimates. http.//Realcliamte.org suggests that sea level dropped (that is, ice melted) between 700 AD and 1400–1450 AD, corresponding with the medieval warm period, but extending past where Greenland’s west coast began to add ice. And after 1450 or 1500, sea level began to drop slightly until the 1800s where sea level began to rise again. Not all the charts are the same and precise dates are tricky, but sea level does give us a pretty good measurement of total glacial ice increase or decrease. 2000 Years of Sea Level (+updates) So this is about what you’d expect. During the Medieval Warm period, ice melted and sea level rose. During the little ice age, ice reformed and sea level fell, but less than what melted, so globally, there’s less ice, say in 1980 than 1000 years ago, but Western Greenland is unusual, in that it had a temperature drop of more degrees and earlier than the rest of the planet, which lead to more ice formation. This is only a rough approximation based on a few articles and some ice core data, but I think it’s generally correct. This article goes into more detail and over a longer period of time for further reading, if interested. Greenland's shrunken ice sheet.We've been here before