2010-09-12 13:43:27Basic Rebuttal: Greenland is gaining ice-Revised
Robert Way

robert_way19@hotmail...
142.162.205.242
Confusion caused by anecdotes of structures being buried by accumulating snow on Greenland's ice sheet leads some skeptics to believe Greenland is Gaining Ice. As always, the best way to tease out the truth here by following the research of scientists investigating Greenland's ice mass balance.

In general, the best available science tells us that Greenland is losing ice extensively (Figure 1) and that these losses have drastically increased since the year 2000.


Figure 1: Estimated Greenland Ice Sheet mass balance changes since 1950 using three different methods (Jiang 2010).
Mass Balance Measurement Techniques are discussed here .


The evidence suggested by a multitude of different measurement techniques suggests that not only is Greenland losing ice but that these ice losses are accelerating at a rapid pace (Velicogna 2009). Further evidence suggests that although ice losses have up to this point primarily occurred in the South and Southwest portions of Greenland, these losses are now spreading to the Northwest sector of the ice sheet (Khan et al 2010).

Although there have been some gains at high altitudes, significant ice losses are occurring at low altitudes (Wouters 2008) along the coastline where glaciers are calving ice into the oceans far quicker than ice is being accumulated at the top of the ice sheet (Rignot and Kanagaratnam 2007).

In conclusion Greenland is losing ice extensively along its margins where fast flowing ice streams are pushing more ice into the ocean than is gained in the center of the ice sheet. For more information on how ice sheets lose mass, a more comprehensive discussion is available here.

2010-09-12 14:38:13The inevitable question
John Cook

john@skepticalscience...
121.222.93.62
You know someone's gonna bring it up, the Wu study which shows GRACE data about half the ice loss as recent GRACE data. Wu finds ice loss of 104 gigatonnes per year over 2002 to 2008. How does that fit with the various estimates?
2010-09-12 16:03:48That graph
gpwayne
Graham Wayne
graham@gpwayne...
86.158.204.104

Sorry Robert, but that graph is not suitable for a basic rebuttal in my opinion. You deal with this kind of stuff all day long, so it's probably very straightforward to you. Punters will take one look at it and turn on the TV instead.

I also think it's worth considering a broader picture that is less condemnatory - the opening remarks could be seen as confrontational and a bit superior. Why not simply state what the argument is and then look at some easy to understand examples of measurement systems - the GPS units in the bedrock are very interesting and their measurements of glacial isostatic adjustment is a nice physical demonstration of the change in mass balance, and a nice demonstration also of complementary data sources that help us improve the accuracy of such measurements.

As for the Wu paper (which combines GPS and Grace data to produce the lower negative mass balance estimate for both Greenland and Antarctic ice caps), this I think alludes to a bigger issue - the uncertainty in all this. As keen as we all are, we cannot afford to understate the uncertainty and must be absolutely candid about how little we know about the Antarctic. I don't see how you can 'position' the Wu findings, except to say that it's a good demonstration of how science is progressing, and that none of these findings tell us much about the state of the global climate because it is such a unique - and isolated - microclimate. (If you fancied it, a line or two about the Grace pair, and a little mention of forthcoming Cryrosat II-based studies would add a little background).

One last point. I think it is helpful to flesh out these basic rebuttals with some background, and here I would at least attempt some clarification of the confusion between air temps, surface melt, and basal/buttress melt at the edges. It is the loss of butresses and the lubrication through water falling through moraines that is speeding up the natural calving. A common misconception is that the ice is melting at the surface, rather than from below and at the coast - hence the common sceptic argument that the air temperatures are far too low to induce the kind of negative mass balance reported. 

(Oh, don't forget the hilarious 'the ice sits in a depression so it can't go into the sea' argument. Maybe not that hilarious, now I think on it)

2010-09-13 02:47:11Comment
Robert Way

robert_way19@hotmail...
142.162.205.242
Graham I agree with some of your criticisms but I do think it will be somewhat difficult to write this lets say economically if I incorporate all of them. Perhaps with respect to the difference between how ice losses occur I could link to my post on how ice sheets lose mass and for the measurement techniques I could link to part 2 how do we measure ice sheet changes. That way the background reading is there if someone wants to take a look. In terms of the Wu paper as originally brought up by John, I think the Wu paper fits in the middle on that scale. That is why I don't know if it is necessary to really get too involved in it. That being said I can make a mention of it and try to incorporate it somehow but really it will just fit the same or a bit more than the altimetry estimates...

In terms of the original graphic. Yes it is a bit cumbersome but I don't know what else to show. If I show the old grace estimates then I will be accused of fear-mongering with the Wu paper and if I put Wu in then I feel a little like I might be jumping the gun. I don't know if that study will have errors or not in it but i'm sure if it does it will only push the number up to say 150... so really i'm at a loss about how to show that multiple different measurement techniques all show the same thing in a graph, any ideas?
2010-09-13 03:27:49
nealjking

nealjking@gmail...
84.151.43.165
I don't understand the leading statement about "subjective science." What does this phrase mean, and what are you trying to say?
2010-09-13 06:31:48Comment
Robert Way

robert_way19@hotmail...
142.162.205.242
i meant to say objective. woops
2010-09-13 15:26:53Comment
Robert Way

robert_way19@hotmail...
142.162.13.137
Bamber and Riva 2010 use Van Den Broeke`s (2009) estimate for Greenland and Rignot`s (2008 a and b) estimates as long as Hock et al. (2008 or 2009) estimates to make their Antarctic assessment. I think the Greenland numbers are pretty safe to conclude at anywhere from 100 to 200 with a middle value of 150 (166 from Van Den Broeke) being a likely a good estimate. The Wu et al. study doesnt make an atmospheric correction which will add on another 5 Gt so that puts it at 109 anyways... We will see how Bamber and Riva react to my commentary...
2010-09-13 15:27:31Revised
Robert Way

robert_way19@hotmail...
142.162.13.137
I did a few minor revisions but am still trying to figure out some issues first although it can all be a little uncertain.
2010-09-13 18:10:34
Paul D

chillcast@googlemail...
82.18.130.183

Personally I think it might be wise to re-write the first two sentences.

There seems to be a level of ridiculing the people that make claims about Greenland ice increasing.
That is OK, but I think if you want to persuade people you are correct, then a more diplomatic use of words might be appropriate?

It's easy to turn people away by saying the others are stupid.
Let the less diplomatic statements be made in the comments?

2010-09-13 18:25:04
Paul D

chillcast@googlemail...
82.18.130.183

I agree with gpwayne about the diagram.

How about two diagrams?

The one you have is a bit cluttered and takes a while for even a well educated person (like myself!) to interpret.
How about keeping that graph and also including a simplified version with only a few key data points and possibly without the error lines??
With an explanation of why you have included a simpler graph as well as the full graph, so that the skeptics don't think you are doctoring the info.

Is it possible to click on a button that says simplified version and swap the complex one for the simplified one. So the user can choose depending on their knowledge level?

Another alternative is to have a slide show type presentation and circle the points on the diagram as a narration explains them.

Also you could cross reference other SkeptcalScience info that refers to GRACE, or maybe link to the official GRACE pages.

2010-09-13 18:44:04I agree with The Ville
nealjking

nealjking@gmail...
91.33.124.246

about the tone: Words like "ridiculous" and "unrealistic" come across as hostile and defensive. We don't have to do that: We have the science on our side.

You might also consider: Why do people say that the Greenland iceshelf is gaining ice? Is there something they are apprehending incorrectly, or is it just based on lies? Personally, I always like to hear what the other side's error is.

(Although I have also heard the school of thought that "refuting errors of those already convinced doesn't work, it only reinforces them". I guess I'm a believer in reason & discussion.)

2010-09-13 23:49:58Comment
Robert Way

robert_way19@hotmail...
142.162.13.137
I've tried to address the tone of the starting two sentences. My issue really is the graph though and I don't know how to rectify the issue. I did not plot it up myself and I think it is important to show multiple sources of evidence and not just a GRACE map... especially with the Wu et al. 2010 study...
2010-09-14 00:23:20Why not just
nealjking

nealjking@gmail...
91.33.124.246

replace:

"There are some individuals out there who still make grand statements such"

by:

"Some people say"

?

Check out:

http://www.skepticalscience.com/thread.php?t=170

 

2010-09-14 02:48:37Comment
Robert Way

robert_way19@hotmail...
142.162.13.137
Okay Neal,
I understand you're trying to tell me to go read that paper but in some ways I take it as an insinuation that I do not know how to effectively convey the subject matter. I think that as i've mentioned before with respect to Greenland, Antarctica and Glaciers gaining ice that skeptics making the argument of either are only arguing in bad faith because the literature has been clear and concise for so long. Skeptical science is about informing the public sure, but we also have to be proactive in trying to rebut common skeptical themes which are obviously being used out there in bad faith.
2010-09-14 03:25:27
nealjking

nealjking@gmail...
91.33.124.246

Robert Way,

It is much more effective to show that your opponent is in error by going through the reasoning, than by calling him a liar: That just invites the corresponding response, and the whole discussion just goes down the toilet. Who wins in that case? The skeptics do: Because the neutral reader just draws the conclusion that both sides are a bunch of jerks, and the science gets flushed, too.

These articles are not a session in a debate: When the reader opens to one of them, nobody has prepped him in any predictable way. When the article starts off by attacking people who are not present in the discussion (because there has been no discussion), it comes off as clearly partisan, highly antagonistic and probably biased. This is not a good way to influence anyone.

 

2010-09-15 03:28:33
doug_bostrom

dbostrom@clearwire...
184.77.83.151

Perhaps the issue of tone in the first paragraph can be resolved through sticking w/John's example of first and separately delineating the general skeptic argument, then talking about the science. Also, -are- there any actual scientists making the claim that Greenland is gaining ice, as opposed to anecdotes about structures being buried in snow accumulation?

As in, "Confusion caused by anecdotes of structures being buried by accumulating snow on Greenland's ice sheet leads some skeptics to believe Greenland is accumulating more ice. As always, the best way to tease out the truth here by following the research of scientists investigating Greenland's ice mass balance."

The graph could perhaps be distilled into three bars arranged against neutral balance? 

 

2010-09-15 05:15:41
Robert Way

robert_way19@hotmail...
134.153.14.191
neal,

rather than engage in a looping debate on the ethical boundaries of writing these articles, i'm just going to just say agree to disagree and go with doug's suggestion. I think you have built up a few sentences which were likely not written in the most effective way into a complete evisceration of the opposing side. Of course I didn't expect the original way it was written to be the final copy and that is why I had it altered once again prior to your most recent tirade. I don't feel as though the commentary with respect to the glaciers are growing was warranted and I feel as though what should of just been a respectful disagreement was taken a little over the line in saying the article gave the impression of being clearly partisan, highly antagonistic and probably biased.

We may not fully agree on approaches but remaining fully civil is something that I think is necessary for moving forward. Authors can disagree and still come to amicable conclusions.
2010-09-16 03:08:42
doug_bostrom

dbostrom@clearwire...
184.77.83.151
Time for a round of "Kumbaya," I think. :-)
2010-09-16 04:32:09Comment
Robert Way

robert_way19@hotmail...
142.162.13.137
Agreed, I implemented your revisions doug
2010-09-21 21:35:24
doug_bostrom

dbostrom@clearwire...
184.77.83.151
Ok, the perfect is the enemy of the good. This is languishing, apparently because the graph is insufficiently simple? It's not so complicated as to hopelessly confuse the issue, surely. 
2010-09-22 15:49:36Seconded
James Wight

jameswight@southernphone.com...
58.105.164.221
I’m happy with this rebuttal with or without the graph. I’d change “gains/stabilization” to “gains”, though.
2010-09-22 23:11:07comment
Robert Way

robert_way19@hotmail...
134.153.10.5
Sorry about the languishing. had a personal issue come up and we got hit by a hurricane this week.
2010-09-23 04:52:59Comment
Robert Way

robert_way19@hotmail...
142.162.11.53
I fixed the stabilization part. I actually think personally that its okay to go. The graph really isn't as difficult as people think and there is a link to discussion of the methods...
2010-09-23 06:24:57
Riccardo

riccardoreitano@tiscali...
93.147.82.130
Looks good to me.
2010-09-23 10:13:14Late comment
Andy S

skucea@telus...
66.183.162.8

First, my apologies for taking a break from SkSc for a while--my day job and other climate-related activities got in the way.

I like this article but I think that some further explanation of the the measurement of the parameters in the graph is required. The target audience won't know what GRACE, Altimetry or Net accumulation/loss mean and I think that the article would be strengthened for a beginner if there was some simple explanation of what the terms mean. (I have no problem with the figure by the way).  For example (and this is just off the top of my head):

Net accumulation/loss means that scientists measure the amount of snow being added to the top of the ice sheet and compare this with how quickly ice is being lost at the fringes of the sheet by measuring the speed that the outlet glaciers are moving into the sea, rather like a bank statement keeping track of deposits and withdrawals. GRACE gravity is a satellite-based technology that effectively weighs the ice sheet. Altimetry uses radar and lasers to measure the height--and thus the volume--of the ice. These three techniques are different ways of keeping track of changes in the size of the ice sheet.

I think that this shows that scientists are using different and (mostly) independent techniques to actually measure the loss of ice and do not rely on anecdotes like photographs of sinking buildings. That's the main point of the rebuttal.

 I think that leaving Wu out is a good idea, although that paper does need to be addressed at the intermediate level. 

Perhaps a line should be added that explains that the ice loss rate is still quite small (ie it would take XXX years to get rid of the whole ice sheet at these rates) but that what is important is that this rate of ice loss is increasing; and nobody knows for sure how much the rate will continue to increase in the future. (Some skeptics are sure to chime in that the "losing ice extensively" means some tiny annual percentage of the entire sheet). I note that there is already a comment about acceleration, but I think that the concept needs more emphasis, along with some brief explanation as to why it is important.

There is a typo:

 ...the truth here is by following... (second sentence)

 

 

2010-09-24 01:20:50comment
Robert Way

robert_way19@hotmail...
134.153.10.206
I think in the intermediate rebuttal many of your suggestions are incorporated. I don't think introducing questions of how long it would take to melt are necessary in this case because it changes so frequently and since there's no "best" estimate for the losses. I think the Wu et al. paper will be addressed soon but the Bamber paper in the cryosphere discussions concludes that although Wu et al's method is novel and will be good in the future, that they have too few GPS stations for their analysis to be considered a best estimate. They use the estimate from Van Den Broeke et al. 2009 (166 gt)

In Terms of the explanation of the methods. I put a link there which explains the different measurement techniques for ice sheets. I can add in a few lines under the figure and say more information can be found here and link to the discussion if you prefer.


2010-09-25 23:51:59
Anne-Marie Blackburn
Anne-Marie Blackburn
bioluminescence@hotmail.co...
80.42.215.97
Ready to go for me.
2010-09-28 13:30:14Publishing now
John Cook

john@skepticalscience...
124.185.151.34
I agree with Robert re the importance of this graph. I think a key point is that we have multiple independent measurements of ice loss and that graph communicates it well. The only way I could think to simplify it would be to remove the uncertainty bars (which I'm sure would have scientists grinding their teeth with consternation). I don't think it's a deal breaker either way.
2010-09-28 14:30:27
doug_bostrom

dbostrom@clearwire...
184.77.83.151

Maybe we should commit ourselves to retaining error bars where they appear in "quoted" graphs, develop a little standard box explaining what they are? 

Actively removing error bars makes me feel squeamish. As you say, JC, not a deal breaker, but still, urgh. 

Speaking on a broader level, the other day a commenter on Chris Colose's explanation of sensitivity at RealClimate was fairly insistent that all basic explanations should be targeted to a third grader. I guess I've already said it before, but I do believe adhering to such a specification is arguably a capitulation to beliefs inculcated not by exposure to "ordinary" people but instead by endlessly arguing with dead-enders such as "cruzn246" who meticulously cultivate synthetic obduracy. Point is, let's not be fooled by the people who show up on comment threads, let's not think they're a productive target audience. 

Here's what the diehard cynic in me wonders: Is the average person drawn to SkS so stupid and/or ignorant they cannot grasp things such as error bars? If so, what's the point of all this? People so wretchedly impoverished are going to be putty in the hands of whomever is the last person they hear speaking. 

Been a long day. I need to park it.  

2010-09-28 15:34:08First comment to this blog post
John Cook

john@skepticalscience...
124.186.160.198

http://www.skepticalscience.com/Is-Greenland-losing-ice.html#26099

I called it (see above) :-)

2010-09-28 15:40:53Level of scientific explanation
John Cook

john@skepticalscience...
124.186.160.198

I have two anecdotes on this topic. Firstly, my sister-in-law, genuinely wanting to know what's going on with climate, befuddled by my level of explanations even though commenters here say it's easy enough for a highschooler to understand (she has a tertiary degree, in journalism though).

Secondly, doing a radio interview with a radio station in the Netherlands and talking about the iPhone app, she opened up it up while on the air, picked an argument at random, read my explanation and couldn't understand it at all.

The plain English arguments are very clearly NOT written to convert skeptics, to persuade diehard deniers. That's not their purpose at all. They are written for the average person who is genuinely curious about climate, who wants to know the answer to a question - not someone who already has the answer in their heads.

An interesting experiment might be to show Robert's blog post to a few non-scientist friends, see if they intuitively get the graph.

Re the error bars, my approach is a graph should tell a story. Are the error bars essential to tell that story? They do provide more scientific rigour, give proper context of how uncertain the data is, but they don't add to the essential narrative (multiple measurements find accelerating ice loss). So I consider them expendable for a basic version.

2010-09-28 17:14:26Levels of language
nealjking

nealjking@gmail...
84.151.30.233

John,

Your sister-in-law is a legitimate member of the target audience. If she isn't getting our Basic-level explanation, we're missing the target.

I think the demand for a "third-grade" level of writing, however, is too severe. I have generally heard that the right level for things you want people to get is eighth-grade level.

I believe that many of the Basic-level articles are written with our critics in mind - very defensively. That may keep them less impeachable by well-armed skeptics, but also makes them difficult for your sister-in-law to understand. 

The Basic-level articles should be as simple as possible, both in content and language, without being wrong; but the caveats and "corner conditions" should be in the Advanced/Intermediate articles.

At some point, when the article-generation process has slowed down, it would be good if you could find a writer that can go systematically through the Basics and work with the authors to produce an eighth-grade level version. Right now, I fear that your sister-in-law's reaction may be far too common.

2010-09-28 17:47:37Sister-in-law reaction
John Cook

john@skepticalscience...
124.186.160.198
No, her comment about my website was a year or so ago, back when there were only intermediate-level explanations. The current basic explanations are a great improvement. In some cases, they could be simplified further but they're already a great contribution.
2010-09-28 20:09:11
nealjking

nealjking@gmail...
84.151.30.233

That would be a relief.

By the way, have you received any more recent feedback from her?

2010-09-28 20:45:42No more feedback from sister in law
John Cook

john@skepticalscience...
124.186.160.198
She doesn't frequent the site that often. Keep in mind she's married to a skeptic, her father in law (my wife's dad) is a staunch skeptic as is my wife's other brother. If you hadn't worked it out, I married into a very conservative family. Fortunately my wife is not a skeptic and in fact has had some epic arguments with her dad in which she argued like a climate champion.

so what I'm saying is you only get one chance to make a first impression and I dunno if I'll get her to visit the site again. The in-laws don't seem that keen to talk climate with me for some reason.

2010-09-28 21:00:48
Riccardo

riccardoreitano@tiscali...
192.84.150.209
"The in-laws don't seem that keen to talk climate with me for some obvious reason."  :D
2010-09-28 23:16:13
doug_bostrom

dbostrom@clearwire...
184.77.83.151

Hah, a few hours of tossing and turning, trying to find a comfortable position and I'm a new man!

I'm ok w/an eighth-grade level because I agree that to a certain extent writing for the public is sort of like cooking for the public; if your patrons are turned off on the first visit, they won't soon be back. It's arguably possible to write an article accessible to the imaginary eighth-grader that is not a turn off for an adult, not so at the third-grade level. 

Here's something to consider about objectives that I think expresses my root concern better than talk of stupid versus ignorant. As Neal says, there's no point in directly "writing against" skeptics themselves. Instead, what about thinking in terms of the most important white space in our tractable readers' minds? Thinking of a reader without a hardened set of beliefs, what are the most important concepts for occupying the tabula rasa? How can we best provide broad-spectrum inoculation against folly? What are the lessons we can convey that are not only specific to a particular sub-topic but are also portable across the realm of critical thinking about science?

I think the reason I was gagging on removing error bars is because at some level I was imagining the following conversation and opportunity for a cognitive defeat:

"I read on Skeptical Science that climate indicator Y was steadily increasing."

"Yeah? Did they tell you about the uncertainty of those measurements? Did you know there are errors in the data?"

At which point the conversation forks.

Many outcomes are possible, but given our experience we know the skeptic likely either encounters resistance on the meta-issue of error, ends up failing as usual to change a mind already made up because the conversation stalls on error, or is free to proceed with effectively casting doubt on the core concept of climate change. Either we've filled in the blanks on error, or the skeptic is gifted with an open, undefended field, is free to mislead on error while creating the impression that SkS is less than forthright. 

There's no perfect solution for this. It's a tricky thing, deciding what extra freight might be piled onto a given rebuttal; a brief rebuttal especially can't withstand too much overhead. Yet each contact we make is an opportunity for accomplishing a broader, more general purpose and is a pity to waste. For authors this is a bit challenging because if-- for instance-- SkS were to adopt or permit 3 or perhaps 5 most important general ideas for critical thinking about science and actively promote those across articles, that means a certain amount of redundancy in our collective writing. 

Thinking of this as a strategic war of communications, what tactical weapons ought to be on every soldier's belt? If you've got bullets but don't have a rifle, where are you? As a specific example, the concept of uncertainty is arguably in the top class of weapons for punching holes of doubt in the minds of the public, for eroding confidence in a way that arrests chances for activating people to carry their convictions to the ballot box. Why? Because thinking about uncertainty is a key part of doing science. If you don't account for uncertainty, you're not properly equipped to perform or defend scientific research. 

There are other examples of mandatory minimum equipment for thinking about science, for creating durable and flexible mechanisms for sorting truth from fiction. We can't convey all of them simultaneously in one article without it becoming too cumbersome. We can however aim for a statistical approach to article composition ensuring that all of these important things are included in some proportion of articles, thus are encountered and absorbed by an acceptable number of readers.

In a nutshell, the education about climate science we've got to do here will ultimately fail if our readers don't viscerally understand the meaning behind "scientific." Failing that, it's "he said, she said" with no means to discriminate between truth and fiction, what SkS is actually saying when we mention "here's what the science says." Failing that understanding, the loudest and most frequent repetition will win the war, and we know who has the biggest, most vigorous megaphone.  

2010-09-29 01:20:06
nealjking

nealjking@gmail...
84.151.30.233

wrt error bars: I'm in favor of them. But, just as with any other graphic, it's useful to talk your reader through them: What is s/he supposed to be seeing in this graph? Spell it out.

wrt 8th-grade level: I think a major issue is style. I would cut back on the use of the passive, difficult though that may be for technical information. What Rutherford was saying about explaining to the barmaid. Use language that "hits the ground running": words that are shorter rather than longer, simpler sentence construction that doesn't get in the way. That doesn't mean patronizing, but it does mean slightly informal.

For a level set: The language we are using in almost every note above is way higher than 8th-grade.  Think about advertising. Think about announcements at the metro station. Right now, we are talking to each other; but when we write Basic-level articles, we need to write for our target audience.

Here's a hint:

http://en.wikipedia.org/wiki/Flesch%E2%80%93Kincaid_readability_test

Lower average sentence length and lower average syllables/word are better.

2010-09-29 01:52:49
doug_bostrom

dbostrom@clearwire...
184.77.83.151
Should clarify, this is not a beat-up on Robert! Some of the content here might be moved to a general thread, up a level. 
2010-09-29 01:55:23
nealjking

nealjking@gmail...
84.151.30.233

doug,

Agree.

2010-09-29 04:38:27
Paul D

chillcast@googlemail...
82.18.130.183
good to go IMO