2011-03-04 04:51:29Icing the Medieval Warm Period . Treehugger mod finally approved my response
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

John has suggested that, if this passes group peer-review here, we try and develop this piece into a form acceptable for The Guardian and/or Treehugger.com.  So thank you all in advance for your feedback on this first draft.

Blog post is here:  http://www.skepticalscience.com/Icing_The_MWP.html

 

Edit:  Revised copy below

 


 

Treehugger moderation experience feedback:

I posed a response to Orkneygal, as her linked source didn't say what she said it did, but my response did not gain approval from the moderator.  Funny that my first comment received no such moderation.

I know, I know bitchin' about moderation again.  Payback karma?

2011-03-04 05:10:09comments
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

Firstly, bear in mind that mainstream media sources like The Guardian don't often publish figures in their articles (they cut out the figure I included in my Case Study post).  The Moberg graph is nice, but unnecessary, so it may be better just to remove it.  I'd also suggest getting rid of the section headings.  Again it's not something that mainstream media articles generally use.

"It's into this debate that comes information to shed new light on the subject." => This sentence is a bit clunky.  I'd rephrase to something like "A new study has been published which sheds new light on this debate."  I'd also remove the "2011" in the next sentence ("recently published" tells the reader it's from 2011) and move the hyperlink to the title of the paper.

"many hundred years later" => a very cold period many hundreds of years later

"What the authors research finds" => What the authors' research finds

"Indeed, recent information from Pelto 2010" => Another recent study by Mauri Pelto

"shows that glaciers without a consistent accumulation zone will not survive" => can you explain what an "accumulation zone" is in layman terms?

"What this means for the MWP" => you need to define "MWP" when you first use the term

"Since that did not happen, than the temperatures then could only have been warm for a part of the MWP" => Since that did not happen, global temperatures could only have been...

The 'linked response' bullets are kind of confusing.

"The result:  Regionally, variably warm areas interrupted by periods of cooling, interspersed with variable patterns of precipitation." => this sentence is a bit confusing too.  Maybe something like "As a result of these linked responses, Koch & Clague suggest that glaciers were able to advance during the MWP because warm regional areas were interrupted by periods of cooling, interspersed with variable patterns of precipitation."

2011-03-04 05:36:20Thanks, Dana; implemented changes
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102
See updated version below
2011-03-04 05:47:44
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.207.168

What Dana said. No graphs, no headings, simplify the language. Always strikes me as a double standard because the business section of any newspaper is loaded with jargon!. Maybe the target audience is just money-grubbing tossers?.

Possibly the introduction is a tad too combative. The fact that the world is warming is indeed a fact, you should address that in a nonchalant kind of way. That's guaranteed to wind up the "skeptics" without turning off the general reader.

2011-03-04 05:54:46comments
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

Looks good.  A few other comments:

"A new study has been published which sheds new light on this debate" => says "new" twice in one sentence.  Maybe change to "A study has recently been published which sheds new light..."

I think change "Koch & Clague 2011" to just "Koch & Clague".  Mainstream media articles usually just say "a new study" and maybe reference the lead author.  Same thing for Pelto, I think get rid of "(Pelto 2010)" and move the link to the text saying "another recent study".

The end is much clearer now. 

2011-03-04 06:04:38
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.207.168

One other thing, is "precipitation" too high-falutin' a word to use?. 

2011-03-04 06:06:40
Ari Jokimäki

arijmaki@yahoo...
91.154.108.124

Here's another just recently published paper showing a 4000-year hockey stick in Spain:

"Remarkably, the presented records allow direct comparison of recent warming with former warm intervals such as the Roman or the Medieval periods. That comparison reveals the 20th Century as the time with highest surface temperatures of the last 4000 years for the studied area."

 

2011-03-04 06:14:46Thanks guys; updated per your valued guidance, below
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

Icing the Medieval Warm Period

Posted on 4 March 2011 by Daniel Bailey

"It's cold out!" 

Not strange to hear that during the winter, here in the Northern Hemisphere.  But strange to hear that raised as an objection in the warming world in which we live today.  How much warmer it's going to get and what are the related impacts is what science is currently debating.

One of the commonly raised objections from those who would have us debate even the existence of gravity is that "It was warmer in the Medieval Warm Period."  This is an innocent, but untrue, claim clearly unsupported by the available literature.  Indeed, Martín-Chivelet et al reveals the 20th Century as the time with highest surface temperatures of the last 4000 years.

The Medieval Warm Period (MWP) was a period of supposedly warm climate during the early part of the past thousand years. How long it lasted, what areas were affected and even if it existed have been questioned.  Some areas seem to have been affected more by changes in precipitation than in temperature.

A study has been recently published which sheds new light on this debate.  Koch & Clague, in their paper Extensive glaciers in northwest North America during Medieval time, provide new evidence showing that several glaciers in western North America and elsewhere in the world advanced during Medieval time and that some of these glaciers achieved extents similar to those at the peak of the Little Ice Age, a very cold period many hundreds of years later.

What the authors' research finds is that these glacial responses could not have happened in a world with a climate similar to ours today. Indeed, recent studies (here and here) by Mauri Pelto show that glaciers without a consistent accumulation zone (where the glacier "packs on weight") will not survive.  This helps explain why today's glaciers (responding to today's warming world) are retreating to their smallest areas in many thousands of years, exposing their longer histories in the form of buried datable material for scientists like Koch & Clague to decode.

What this means for the MWP is that if summers were as warm then as today, glaciers globally should have retreated significantly.  Changes affecting glaciers around the world require global effects.  Since that did not happen, global temperatures then could only have been warm for a part of the MWP.

So what else could explain these glacier advances in a supposedly warm world?  The most likely answer is that changes in factors besides temperatures played a significant role.  Koch & Clague find a linked response between:

  • increased winter precipitation
  • changes in solar activity
  • changes in the El Niño/La Niña (a Pacific Ocean weather pattern affecting the entire globe) in response to variations in solar activity

As a result of these linked responses, Koch & Clague suggest that glaciers were able to advance during the MWP because warm regional areas were interrupted by periods of cooling, interspersed with variable patterns of precipitation.  Given the length and breadth of the information we now know, Koch & Clague make a substantial case that the MWP should be more aptly named the Medieval Climate Anomaly.

 

Acknowledgements:

To glaciologist Mauri Pelto, for being kind enough to lend his perspectives and expertise.  To the many other contributing authors at Skeptical Science for their valued efforts as well.  Many thanks, all.

2011-03-04 06:15:59precipitation
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

The thought crossed my mind to change "precipitation" to "rain/snowfall", but people hear "precipitation" all the time in their local news weather forecasts, so it should be fine.

2011-03-04 07:02:19Thanks, guys!
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

OK, anybody else?

2011-03-04 11:51:47Just emailed it to Treehugger
John Cook

john@skepticalscience...
124.186.229.6

Coincidentally, just got an email from Treehugger this morning asking if we were going to send any articles - I sent this one just now, will send Dana's later today. Thanks Daniel, hope this gets read by many!

2011-03-05 07:39:31Heard back from Treehugger
John Cook

john@skepticalscience...
124.186.229.6
Said they'd post Daniel's post over the weekend. Will keep everyone posted.

BTW, nice too that the SkS thread has Ljungqvist commenting.

2011-03-05 12:09:31Sweet!
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

Thanks for the update; I'll keep a look out!

2011-03-06 04:12:31Treehugger posted it
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

http://www.treehugger.com/files/2011/03/icing-the-medieval-warm-period.php

2011-03-06 06:04:00
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.236.10

Well done Yooper. 

2011-03-06 08:11:52
nealjking

nealjking@gmail...
91.33.103.53

Looks good!

2011-03-06 09:49:53
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

Thanks!

2011-03-07 05:45:02Re: Treehugger moderation
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

Bump - see comment at top

2011-03-08 02:30:26Ne'er mind
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

OK, I retract my moderation complaint - in part.  The mod's finally approved my comment I bitched about earlier.

Temporarily quarantined comment posted below:


Then there's the borehole records, which show late 20th-Century temperatures to be about 0.5 C above those of the MWP.

Reading your referenced linked study (open source copy here), nowhere do I find anything which indicates that the Amery Ice Shelf during "The MWP at ca. 750 14C yr BP was likely warmer than at any time during the CWP.". Isn't it curious that Hemer and Harris say nothing of the sort in their study? Just that a major retreat of the Amery Ice Shelf "may have occurred during the mid-Holocene climatic optimum".

Very odd.

The Yooper