2010-08-18 04:23:13Creating a post regarding "Greenland used to be Green." Need help.
Rob Honeycutt


 Hello gang,

I'm attempting to create a rebuttal to the following article that has been reposted on WUWT.  I posted a claim to the "Greenland used to be Green" rebuttal.


I'll post what I've written so far but what I'm really looking to do mostly here is find out what 20th century warming has been in Greenland.  I believe this article suffers from the malady known as "hide the incline."  I found a recent article that says that warming in Greenland since 1970 has been about 3C but it offers no sources.


 I found one paper on temperature records for Greenland but being a non-scientist I really can't make heads or tails of it.  It looks all over the map from my perspective.  Survey of Greenland Instrumental Temperature Record 1873-2001. Jason E Box 2002 published in the International Journal of Climatology. 

Can any of you point me in the right direction to find what the rise in average temperature of Greenland has been since 1900?  My suspicion is that it may be as much as 5C which would have a very dramatic visual effect if amended to each of the charts presented in this article.

 Here is a current draft of the post I'm writing...

Why do they call it "Green" land?

As I've mentioned in previous pieces on Skeptical Science, I am a non-scientist who is concerned about, and wants to better understand, the issue of climate change.  I've spent the better part of 3 years of my spare time devoted to this issue.  Having two small children compels me to have concern for the world we are creating for them.  One of my ways of learning is to find arguments.  I get out into the ring on various websites, blogs and on youtube.  I find climate change deniers and take the gloves off.  

So, the other day one person on a youtube video about Chris Monckton says to me,  "Just tell me this.  Why is Greenland called 'Green' land."

My immediate response was, "Well, why is Iceland called 'Ice' land when it is right next door to 'Green' land."

Yes.  It's a silly response to a silly question that has no bearing on the overall issue.  But sometimes these silly exchanges prompt me to look deeper into an issue.  Then I roll up my sleeves and see if I can try to understand the issue a little better.

This little exchange has caused me to go back and look at another youtube video that I found a few weeks ago.  It is essentially a video repost of a Watts Up With That article that is, in turn, a repost of an article written by J Stores Hall titled Hockey Stick observed in NOAA ice core data.  


Here's how the story goes...

Slide one.

Hey, a hockey stick in the ice core record.

Slide two.

Whoa!  The MWP was way warmer than the hockey stick.

Slide three.

Yeow!  There are MUCH warmer periods before that!

Slide four.

This is normal fluctuation for the past 10,000 years.

Slide five and six.

And it's all part of a generally warm holocene period.

Slide seven.

And this is all just part of normal temperature fluctuations over the past 450,000 years.  So, human-emitted CO2 is not the only thing that could account for recent warming.  

There you go!  Proof positive that we don't have to worry about anything that's going on with the climate today.  Nothing to see here folks.  Just keep moving along.

Call me skeptic on this one.  Reading through the article, even as a non-scientist, I saw lots of red flags.  These red flags prompt me to do just a little bit more leg work that the author himself did on this issue.

Hall states regarding the first slide, "Well, waddaya know - a hockey stick.  In fact, the 'blade' continues up in the 20th century at least another half a degree."  Is this true?  Well, first, this chart suggests that there was 0.5C of warming from maybe about 1830 to 1900.  That's mostly preindustrial.  And this is, as Hall previously states, "It (the central Greenland Ice core) gives us about as close as we can come to a direct, experimental measurement of temperature at that ONE SPOT for the past 50,000 years." 

If this is true, Mr Hall, how can you paste a 20th century global average warming of half a degree onto a temperature record of ONE SPOT?  Call me crazy, but I would want to know what the 20th century warming has been for that ONE SPOT.  

My suspicion here is that due to polar amplification we'd expect to see far more warming in Greenland than the global average. 


Rob Honeycutt 

2010-08-18 04:27:00Comment
Robert Way

I can put something together possibly with respect to this. Might take a day or two but a temperature composite for greenland would not be THAT hard to put together. My problem would be mainly finding the names of all the stations there.

We shall see. I'll take a look at this when I get off work in a couple hours.
2010-08-18 04:51:08
Rob Honeycutt


Thanks Robert...


I'm having a little fun right now with what I might expect to post for "updated" response graphs...  





2010-08-18 06:27:38
Andy S


I think John's original rebuttal is already fairly "basic". But perhaps it could be simplified a bit more and some additional more general non science links added. Might I suggest this: 


There's a picture there showing a Greenland farmer tending his fields with icebergs in the background that is worth a thousand words (or a dozen graphs of recent temperature trends).

I don't think it would be helpful in a "basic" rebuttal to talk about Greenland ice cores since this leads into a potentially confusing discussion about local/global temperature trends measured at the summit of the ice cap, when what matters for this discussion are the local trends near sea level in southern Greenland.

2010-08-18 07:13:38Comment
Robert Way

I'm not sure I trust those graphs you showed. The current warming in Greenland I doubt exceeds the MWP by much and if it does it is only during the 2000s that this became the case... You have to understand that while globally the MWP was colder than now, in the North Atlantic it was likely warmer/as warm as current conditions.
2010-08-18 08:11:31
Rob Honeycutt


There is no data behind the graphs I did at all.  The only thing I was going on is that one article that says that Greenland is 3C warmer than 1970, and adding in some more warming for the period between 1900 and 1970.  

Sorry, I wasn't trying to mislead.  Just thinking out loud. 

2010-08-18 08:41:49
Rob Honeycutt



I guess what I'm trying to do is respond to that specific article written by J Storr Hall.  It's incredibly misleading as far as I can see. What I keep seeing from skeptics who look at the MWP is, they almost invariably leave off current warming.  That first Loehle piece I wrote was the same thing.  He stopped his data at 1935 and said that the MWP was warmer than current temps.  But when you actually add on the rest of the century you get a very different picture.  Basically, it was just putting the blade on his hockey stick for him.

What I'm wondering, is the same thing going on with Hall's representation of the central Greenland ice core data?  He conveniently leaves the data hanging at 1900 and then goes onto say, "See! Look how much warmer it was in the past!"

My speculation is that, because of polar amplification we would expect more warming in Greenland than the global average.  So, as a non-scientist, I'm trying to figure out, if there is one, how to put the blade on Hall's hockey stick.

The Spiegel article you referenced says there's been almost 2C of warming in the past 30 years.  The article I read from the Daily Mail says 3C since the 1970's.  But neither provide source data.  Even just this amount of warming would change the look of the graphs that Hall presents quite dramatically.  

2010-08-18 12:34:02Comment
Robert Way

Robhon, do note that during the 1940s it was likely warmer than now in Greenland. It may have warmed 3 degrees since the 1970s but you rarely see how much it has warmed since the 1940s. I'm working on a temperature composite for the 20 weather stations with data that i could find from around greenland. I should be done tomorrow and I will show you. For the record though, the 1970s is likely also affected by something called the great salinity anomaly (GSA) which is an oceanic process that caused irregularly low temperatures in the north atlantic (sometimes 2 degrees celsius colder) and this can effect the start dates and decadal averages for these things.
2010-08-18 23:10:53Comment
Robert Way

see graph below

And second graph

2010-08-18 23:32:15Comment
Robert Way

As you can see based upon the 1st figure, Greenland's temperatures were higher than present by probably around 1.5 °C during the 1930s-40s. Also note that the data from the early 21st century is lacking and it is plausible that i've missed quite a few stations. That being said, I used data from 15 meteorological stations in general and they were relatively well distributed around the coastline. Furthermore, I also used one site (Alert, NWT because its very close and in an important area that was very under represented (Northwest sector)
2010-08-19 00:39:43Comment
Robert Way


Another thing you might consider noting is that in moburg (2005) the northern Hemisphere temperatures are about the same during the 1940s as they were during the MWP. Therefore if the same mechanisms were at play during both times (Solar, volcanism (low) and the AMO) then the assumption is that the temperature patten was around the same

meaning I personally believe that the 1940 levels are around MWP in Greenland. If the early century warming had prolonged then perhaps we would have seen a greener greenland. The whole point of the MWP is inertia. It lasted a long time and so stuff like glaciers eventually responded to the forcings. The difference is our glaciers and ice caps are now responding to the forcing too but much quicker

2010-08-19 02:24:15
Rob Honeycutt


Thanks a ton for your time on this Robert.

So, what I gather from what you're saying is that, if I append current warming onto the central Greenland ice core graph presented in that Hall article, then what I'm going to get is a very abrupt jump from 1900 up to the 40's and then down and up again.  But all of this in a very short time scale relative to the MWP or warm periods that preceded that.

Would I also be safe in saying that due to the fact that heat continues to accumulate in the oceans, that on our current path we would expect to see a dramatic rise in Greenland temperatures in the near future?  I go back to polar amplification.  If we're anticipating a 2-3C global average this century, we are likely to see an increase in Greenland of 5-6C.

I hope this isn't overreaching on my part.  Something just really bugs me about the Hall article and I want to put it into a broader perspective that points to how selective and misleading it is. 

Thanks again Robert. 

2010-08-19 02:44:48Comment
Robert Way

One thing you would expect is actually for temperature rise to reduce (unless solar kicks in more) as the positive phase of the AMO turns to negative (this results in arctic cooling and antarctic warming)... What is seen in the antarctic records is that when the AMO turns positive it usually cools there but since the most recent positive phase it hasn't cooled but hasn't rapidly warmed either. This is because of AGW keeping the Antarctic from Cooling. My prediction is that the rapid warming we are seeing now in Greenland will eventually slow down when the phase changes but that by the time (35 years) the next positive phase comes in, you will see a double up effect from the positive phase and the greenhouse gas forcings. Just a theory. I thinkhonestly its easy to assume that Greenland overall should see 4 degrees of warming by 2100 easily. Hard to predict all this stuff though... hard topic to deal with that you've picked up. I think you just have to consider that 1940s warming rivals the MWP in Greenland and we are still below those levels. by a good bit in that part of the world. This could change quickly however, especially if solar contributions start up too.
2010-08-19 03:50:13
John Russell


What strikes me from reading the above is that perhaps the temperature of Greenland is no guide as to what anything else does or is doing because it is so heavily influenced by the North Atlantic ocean currents which change and vary based on a multitiude of causes. I think where people maybe go wrong is that they just don't get the complexity of climate in that area of the world and try to extract meaningful evidence to support their positions.  

Best wishes,


2010-08-19 04:10:39
Rob Honeycutt


John Russell, 

That's a good thought.  It might be interesting to try to compare the same time series from the Vostok ice core and see how those oscillations interact. 

2010-08-19 04:18:30Comment
Robert Way

I've done work on the Labrador side of things (North Atlantic sector like greenland) and it is ocean related changes drive the climate there even more than greenland. Things like the AMO is really important in all this. A good paper to look at is chylek et al. 2010 or 2009 (I forget) on the bipolar seesaw of the arctic and antarctic
2010-08-19 10:51:57Rob @ 8:41
Andy S



On another forum some time ago I also attempted a rebuttal of the ice-core temperature record like the one you mentioned on WUWT. A lot of people don't notice that the curve ends in 1900 and, like you, I attempted to graft on a twentieth century curve, with and without polar amplification. I'm fairly sure that's the kind of thing that is going on but having to speculate like that was not very satisfactory. The MWP in Greenland may anyway have been warmer than today. Other climate factors (eg summer vs winter temperature changes, the duration of snow cover, summer sunshine etc) may be more critical than just average annual temperatures. Also, changes to micro-climates in certain south-western valleys may be more important to consider than what's happening at, say, Thule or on top of the ice cap, so averages for temperature trends for the whole island may not be very instructive.

The skeptical argument on  Greenland is fundamentally qualitative and based on imperfect historical records, so for the people who make those arguments, anecdotal reports on recent bumper potato crops may be convincing, at the basic level, anyway. (Of course, potatoes weren't available to the Vikings so you may want to nip that gotcha in the bud!) And be prepared for the corollary arguments to morph from "it's happened before" to "warming is good".