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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Was Greenland really green in the past?

What the science says...

Select a level... Basic Intermediate

The Greenland ice sheet is at least 400,000 years old and warming was not global when Europeans settled in Greeland 1,000 years ago

Climate Myth...

Was Greenland really green in the past?

“CfA's Sallie Baliunas […] refers to the medieval Viking sagas as examples of unusual warming around 1003 A.D. ‘The Vikings established colonies in Greenland at the beginning of the second millennium, but they died out several hundred years later when the climate turned colder,’ she notes.” (William Cromie)

At a glance

The past 2024 years - i.e. everything AD - are referred to by archaeologists as the Common Era (CE). Decades ago, long before the refinements and data-coverage of modern science, the CE was divided into a series of climate epochs. Among these were the 'Mediaeval Warm Period' (MWP), from around 800-1200 CE and the 'Little Ice-Age', from 1200-1850 CE.

Each of these epochs has the origin of its name in older paleoclimatic evidence from the Northern Hemisphere and particularly Europe. But things have moved on. We now know that unlike modern global warming, the MWP was regional in its nature. A particularly warm region was the Northern Atlantic, including southern Greenland.

Icelandic sagas tell how, in 982 CE, Erik the Red was sentenced to exile from Iceland for three years. He had been involved in an escalated dispute with a neighbour that had culminated in several deaths. With a band of fellow Vikings, he set sail towards Greenland. Erik's party landed and settled near the mouth of Tunulliarfik Fjord, which has the modern Innuit settlement of Narsarsuaq at its head. This part of Greenland is a largely ice-free enclave today, situated in the SW part of the island, some 200 km from its southern tip. Legend tells how Erik came up with the name, 'Greenland', in order to attract further settlers. Apparently the ploy worked.

With hundreds of settlers arriving in the SW of Greenland, a mixed economy developed. It was based on combined pastoral farming, hunting and fishing. Livestock were kept mostly for milk, cheese and butter. Meat instead came mostly from hunting, both locally and in seasonal expeditions further north. These longer forays visited areas in which walrus, narwhal and polar bears were abundant. Hides and ivory became export commodities, allowing maritime trade with the rest of Europe, in return for iron, timber and other essentials.

A few centuries into this colonisation, the regional climate deteriorated. Ice-sheets readvanced. Recent research has also shown that sea-levels rose, too. It may seem counter-intuitive, but when ice sheets grow, nearby coasts often drown. Two things work together to cause this: the larger gravitational pull of all the extra ice on the sea surface and the subsidence of Earth's crust due to the added weight of that ice. One recent study has suggested over 200 square kilometres of coastal land - where the settlers would have had many of their farms - were lost. Geophysics has detected remains of some of the settlements, now beneath the waves.

Progressive sea-level rise, likely in tandem with social and environmental factors such as famines, epidemics and harsher weather, took its toll. The Inuit, who had arrived in around 1200 CE, remained in Greenland through the severe cold of the Little Ice Age but by around 1500 CE, the Vikings had vanished for good. Climate change drove them out.

That's what happened to the Vikings. But regional and global climate change are different things. Regional historic change has little bearing on the global events that are happening right now.

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!

Further details

Greenland, the large island situated to the east of Canada between the Arctic and Atlantic oceans, is only green in part. About 80% of the island is covered by the Greenland ice sheet, variably from 400,000 to 800,000 years old.

In the year 982 CE, Viking explorers, mostly operating out of Iceland, began to establish settlements along the south-west coast of Greenland. So what were the conditions like back then? There is evidence that the settled areas, at low levels proximal to fjords, were warmer than today. Driftwood and birch woodlands (Gauthier et al. 2010) provided both timber and fuel - at first. This warmth coincided with the period known as the Medieval Warm Epoch (Lamb 1965), also known as the Medieval Climatic Anomaly or the Medieval Warm Period (MWP), which we will discuss below.

According to the Icelandic sagas, Erik the Red gave Greenland its name, in an attempt to lure settlers in search of land and the promise of a better life. This early bit of estate-agency apparently worked. However, the opportunity may not have been as good as it sounded. The size and age of the ice sheet, which is more than 3 kilometres thick in places, dictates that settlements would have been limited to those relatively small areas in the southern part of the island, with proximity to the coast.

Warming during the MWP was not global

During the MWP, some regions, most notably in the North Atlantic and parts of Europe, were at least as warm as today. However, other regions were colder. Overall, the evidence indicates that global temperatures during this period were similar to those at the middle of the 20th century. The MWP is explored in more depth here.

Not only was Greenland mostly covered in ice when Vikings settled there, but also the relatively warm conditions at the time were not a global phenomenon (fig. 1). This strongly contrasts with what we see today, with observed warming that is truly global in nature.

Reconstructed surface temperature anomalies for the Medieval Warm Period

Figure 1 - Reconstructed surface temperature anomalies for the Medieval Warm Period (950-1250) compared to a 1961-1990 reference period. (Source: Mann et al. 2009)

We can compare this with a similar reconstruction looking at surface temperature anomalies for 2022. This clearly shows the global nature of recent warming.

Surface temperature anomaly for 2022.

Figure 2 - Surface temperature anomaly for 2022, relative to the 1991-2020 mean. Source: NOAA.

Natural versus man-made climate change

Warming can be the result of a number of factors, so that causes of past climate change are not necessarily implicated in current climate change and vice-versa. For instance, the MWP was characterised by relatively high solar activity, low volcanic activity and possible changes in ocean circulation patterns. These factors can explain both the scale and pattern of warmth at that time. However, they cannot explain recent warming. More to the point, in the absence of our major carbon cycle perturbation, changes in natural factors would probably have led to cooling in the past few decades. This contrasts with the multiple lines of evidence pointing to the role played by humans in recent warming, as set out by the graphic in Fig. 3 below.

Graph showing the human fingerprints on global warming

Fig. 3: evidence for anthropogenic global warming - staring us in the face everywhere we look.

What went wrong for the Vikings? Climate change.

Greenland is unlikely to have been radically different just over 1,000 years ago, since much of the ice sheet is at least 400,000 years old. The island was indeed locally green and supported agriculture for a few centuries in localised coastal regions. Nevertheless, around 80% of it would have been just as uninhabitable as it is today. The small area in the SW that was colonised did benefit from the MWP, a strictly regional climate phenomenon.

Ironically, it was climate change that degraded the settlements and had driven the last Vikings out by 1500 CE. The period leading up to this abandonment saw climatic deterioration, as evidenced by highly variable oxygen isotope ratios in local lake sediments (Lasher & Axford 2019). Oxygen isotope ratios are used as a reliable proxy for temperature. This instability marked the cooling into the Little Ice Age and expansion of the southern Greenland ice-sheet. There is evidence that the ice-expansion led to crustal subsidence in the settled area. Gravity-driven sea level rise would also have occurred along proximal coasts (Borreggine et al. 2023). Both phenomena would have caused the loss of good agricultural land. Drowned Viking settlements - or parts thereof - occur in places along the coastline.

The Little Ice Age was also a regional phenomenon. Such regional changes are often examples of internal climate variability, in which existing heat is moved from one part of the climate system to another. That differs from changes in external forcing - such as amounts of Solar irradiance or greenhouse gas levels - that instead change the total amount of heat in the whole system. Nevertheless, as evidenced by what happened to the Vikings, even internal variability can have its impacts.

Last updated on 12 February 2024 by John Mason. View Archives

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Argument Feedback

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Comments 1 to 25 out of 35:

  1. There's a recent paper on Greenland: AB: Radiocarbon dates of emergent organic remains along the western margin of Istorvet ice cap (70.8°N, 22.2°W) indicate a time when the ice cap was smaller than at present. This ice cap, similar to others in east Greenland, exhibits "historic" moraines ~1-2 km in front of the presently retreating ice margins.... Moreover, it indicates warm conditons at this latitude at the time of Norse colonization of Greenland."
  2. Now this may seem off topic but I have read that the name Greenland was a propaganda tool used to attract settlers. The Norse definitely had farms there during the MWP and they appear to have been frozen out after seveal generations when the harbor stopped thawing regularly, but that doesn't mean it was ever a sunny vacationland. They also dubbed the Labrador cost Vinland, but I don't recommend relocating your winery there. Iceland was the opposite idea. The reason I came here is to ask the question where do we look to see where the earth is today on all these reported orbital and processional cycles and where is the earth in these cycles during an ice age?
    Response: NOAA have a page on Milankovitch cycles including links to data & papers on the subject. I haven't read them, let us know if you find something interesting.
  3. It has been proven that Greenland was in fact greener than today. The Glaciers had receded (not disappeared) enough for the lowland areas to be fertile and climate temperate. The argument for the age of the glaciers is a little absurd since we know that it was not a hot house, just somewhat warmer than it is now, enough to be comparable with Iceland or Finland of today, ie. habitable by the vikings.
  4. WA If it was a propaganda tool they would not have named iceland as such. We still can't locate vineland due to the cooling since the discovery.
  5. "If it was a propaganda tool they would not have named iceland as such." Possibly because the places were named by different people, 100 years apart?
  6. wp Possible but not probable. Vineland was named by the greenlanders of that time, we can't identify it to this day because the climate changed.
  7. #5 'Iceland' is from the old Norse word meaning 'isle' co-joined to 'land' thus giving (phonetically) 'iceland'
  8. From the NOAA link in the response to comment 2: "What does The Milankovitch Theory say about future climate change? Orbital changes occur over thousands of years, and the climate system may also take thousands of years to respond to orbital forcing. Theory suggests that the primary driver of ice ages is the total summer radiation received in northern latitude zones where major ice sheets have formed in the past, near 65 degrees north. Past ice ages correlate well to 65N summer insolation (Imbrie 1982). Astronomical calculations show that 65N summer insolation should increase gradually over the next 25,000 years, and that no 65N summer insolation declines sufficient to cause an ice age are expected in the next 50,000 - 100,000 years ( Hollan 2000, Berger 2002). " Don't these "scientists" know the difference between an ice age and a glacation? We ARE in an ice age. So I guess they mean it will end in 50K years or will it reach another glacial maximum? - From the people that brought you AGW.
  9. Greenland was relatively warm between about 800-1300 AD due to the well-defined 1500 year solar cycle, as detailed by Singer and Avery in: "Unstoppable global warming every 1500 years". We are currently in another upswing in the solar cycle, which started about 1750, and which will probably rise about another 0.5-1 degree C over the next few hundred years. Current T to the 21st century is entirely in line with this solar cyle trend. C02 is irrelevant to this cycle,it has been traced 600 times over the last 1 million years in ice cores, and is a result of an overlap between the 87 and 210 year solar cycles. It is well documented, world wide, and climatologists have conveniently forgotten about it (see reference given above). Greenland was settled by vikings during the last solar warming period, which is also why they travelled so far in general during this time period-the northern world was warm.
  10. WP Vinland has been found. It's Lanse Aux Meadows on the Northern Peninsula of Newfoundland where Norse settlements were discovered in the 60s. The mistranslation of Vinland leads many like yourself to think that it means "wine" when in fact, it's a Norse word for "meadow." Which is where Lanse Aux Meadows gets its name today. Iceland was named that before they realized that naming something "Ice" land would deter settlers. Greenland was an attempt to correct that. And, thingadonta, I suggest you check out the argument "it's the sun." Fred Singer is the last person on Earth that you should be listening to when it comes to climate change. He is the same Singer that was also a "expert" when it came to the tobacco industry and proclaimed that second-hand smoke was not harmful to our health. Guess how that worked out? You should get your facts from the climate scientists, not those paid by the energy sector to be experts in the field:
  11. So let me get this straight. A warmer Greenland was a "local phenomenon", but twelve trees in a Siberian forest suffice to represent centuries of global temperature?
  12. oracle2world, I think you got it straight! What you describe with an example, certainly seems to be the way in which the advocates of AGW work, whether they are scientists loyal to IPCC, or just well-read opinion makers. They pick out the data that support the trend that they want to prove, and ignore the data that do not support it. Then they make impressive-looking graphs, where the proper 'corrections' are always added, so that the desired slope of the curve is achieved. The uniformity, the flaw-less consensus, and the lack of debate within the group of AGW supporters, all just works together to make me more skeptical. It would be a healthy sign if they sometimes disagreed, if they ever showed doubt, or if they once in a while agreed that a skeptic arguments had some merit.
  13. Oracle2world> There are several places on this site where the medieval warm period is discussed, like here : It seems to me that they make a strong case (but perhaps not completely airtight one?) for the assumption that a warmer Greenland was a local phenomenon. Its not just an empty claim, there are various data to back it up. I have no idea about what you are hinting at with those Siberian trees, so I can't answer that. Argus> You have a certain not too favourable impression of AGW supporters. I don't share your point of view, and for instance it is not my "impression" that AGW supposters on this site always agree on everything. However, it is very hard to answer such general claim except by similar but opposite generalizations. Maybe you could be more precise about who it is that in your opinion ignores data etc., and give some precise references. Then we could examine the situation together.
  14. Marcel's comments are very wise. Argus, I do not believe your description of "AGW supporters" are reasonable, particularly if you include in that group the IPCC, which has staked out a very middle-of-the-road territory, avoiding extreme claims on either side. For example, from time to time people make claims that climate sensitivity is > 6C per doubling of CO2, but those are generally rejected by mainstream climate scientists. Although the IPCC offers support for a range of 2.0 - 4.5 C, most people seem willing to settle on a probable 3C, in the middle of that range. As for claims that supporters of AGW "never disagree" ... they generally agree on the big picture, but there is lots of disagreement (sometimes vehement!) over the details.
  15. Seems like you all are missing a very important point about Greenland, which you can discover for yourself by visiting any site (like Google Maps) that has satellite pictures taken in the summer. Greenland IS green around the edges (and probably always was), and those edges are all that you're going to see from a Viking longship, or from a settlement on the shore. Around the southern part (where the Viking colonies were) the icecap is many miles inland. (Nor would the Vikings have been unfamiliar with the idea of inland glaciers, or thought them remarkable, as both Norway and Iceland have plenty of them.) There are a lot of theories as to why the Greenland settlements failed. "Climate change" is only one, and in my (non-professional) opinion, at best at minor contributing factor. More likely is that the colonies were just too small to be self-sustaining, so that when regular European trade stopped, they dwindled and failed. More information on past & present Greenland can be found here:
  16. Continuing the conversation from here. Grayman... Your comments about it being warmer in the past based on Greenland once being green are inaccurate. Please look at the website of Dr Jason Box and you can see what the modern temperature record is for Greenland. I would also highly suggest you read two papers on Greenland: Miller 2010... Temperature and precipitation history of the Arctic Alley 2010... History of the Greenland Ice Sheet: paleoclimatic insights I think you'll find the issue is vastly more complex that Vikings living in Greenland.
  17. Rob I will check it out and get back to you.
    Response: [muoncounter] Have a look at CCNY's Greenland 2010 report as well.
  18. And about the naming of the place, why not to look at the original source: Þat sumar fór Eiríkr at byggja land þat, er hann hafði fundit ok hann kallaði Grænland, því at hann kvað menn þat mjök mundu fýsa þangat, ef landit héti vel. 1880 translation: In the summer Eirik went to live in the land which he had discovered, and which he called Greenland, "Because," said he, "men will desire much the more to go there if the land has a good name.
  19. jatufin - Ah yes, marketing...
  20. I had found this article about the Vikings and crops being grown in Greenland and that there were trees growing in Greenland.
  21. Here were some observations of that area from about 1920 to 1940. By the way, I don't seem to hear about volcanic activity in the Arctic & Antarctica areas but you won't hear about that in the mainstream green media. There was an underwater active volcano found in the Sandwich Islands near Antarctica. There was a volcano that went off in Iceland; has any of the data mentioned that? Theres bound to be some volcanic activity going on and thats usually hot. Another thing the Arctic & Antarctica use to be semi tropical. Things change

    [DB] You already posted on these off-topic issues here.  You were responded to immediately afterwards.  Please read those responses.  If you have any questions on those responses, place those questions there, not here.

    Off-topic struck out.

  22. 20, muttkat, Big deal. It's a load of rubbish. Did you actually read the article above, and pursue scientific studies? Or do you subscribe to the theory that if you read it on the Internet, it must be true? Example... from your page:
    During this time, grape vineyards, which require moderate temperatures and a long growing season, were as far north as England. In comparison, today grapes vineyards are only typically as far north as France in Europe.
    And yet from this page:
    There are nearly 400 commercial vineyards in England and Wales covering approximately 2000 acres of land in total.
    So the claim that it was so warm that there were vinyards in England, but not today, is specious. Don't be so gullible.
  23. 21, muttkat, Use the search box in the upper left hand corner. Type in volcano, read and learn. All of this stuff has been covered over and over again. It only takes a moment to read and learn, rather than throwing out questions and comments and links that really just help to make other people as confused as you are. Also note that there is a strict comments policy. Comments are expected to stay on topic. If you have a comment about another topic, find a relevant thread and post your comment there. Off topic comments will be deleted.
  24. The Saga of Erik the Red - Icelandic Saga Database
    1880, English, transl. J. Sephton, from the original 'Eiríks saga rauða'.

    Now, afterwards, during the summer, he proceeded to Iceland, and came to Breidafjordr (Broadfirth). This winter he was with Ingolf, at Holmlatr (Island-litter). During the spring, Thorgest and he fought, and Eirik met with defeat. After that they were reconciled. In the summer Eirik went to live in the land which he had discovered, and which he called Greenland, "Because," said he, "men will desire much the more to go there if the land has a good name."

  25. MWP was global. Handwaiving it away and reconstructing a map in an effort to show it was not global isn't evidence. I will grant that, although there is evidence it was global, perhaps that's open to investigation; hence my first adament comment it was global should be rephrased.

    Of course, so should all claims it was not global as well...:)

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