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on quantities in AR5 (fwd)

Bärbel, the text below is long, meant just as a list of metrologic problems of IPCC documents. A published older letter which does not stress the GtC nonsense at the introduction is

  http://amper.ped.muni.cz/jenik/letters/public/msg00358.html ,

so it can be referenced. My old remark on faults in AR4 is at the end of
 - but the Gt"ofsomething" made not such a attack that time.

(The Oct beg for a pdf versions of figures became obsolete, they are really as good pdf in current typeset version, as the TS answered me.)


---------- Forwarded message ----------
Date: Tue, 29 Oct 2013 14:57:33 +0100 (CET)
From: Jan Hollan <hollan@mail....cz>
To: wg1@ipcc....ch
Subject: vector format of figures in AR5

Dear Technical Support Unit of WG I,

may I ask you for vector versions of the figures in the first part of AR5, esp. from its SPM?



The above beg is what we need urgently. Another issues are my 2 wishes on terminology, don't bother to study them in a hurry.

A) C and CO2 amounts - expressing them transparently is a serious matter.

If you would not mind, I'd change the formulations like "CO2 emissions (PgC)" into transparent "emissions of carbon / Gt" in my translations.

I am sure the 1/1000 of carbon which is not oxidized but emitted as black carbon
           ( http://www.epa.gov/blackcarbon/basic.html ),
 can be neglected when speaking about gigatons.

My decade long experience says that measuring CO2 in strange units

                "1 GtC"  which equal  3.67 Gt

leads to complete confusion of even the most educated public. Even for me it takes time to be certain whether the authors mean

                 1 Gt,   3.67 Gt  or  1/3.67 Gt

in various texts and their parts. Many quotations from such texts get it entirely wrong.

B) on metrology in general -- I strongly recommend to adhere to the NIST rules, and some other improvements to AR#, as I wrote earlier to another addresses:

---------- Forwarded message ----------
Date: Fri, 23 Aug 2013 18:42:54 +0200 (CEST)
From: Jan Hollan <hollan@mail....cz>
To: IPCC-Sec@wmo..., rchrist@wmo...
Cc: midgley@ipcc....ch, ...
Subject: following NIST rules would make AR5 better

Dear Secretary,

I have noticed that WG I drafts for AR5 suffer the same problem as all previous IPCC documents: they ignore some good rules for expressing quantities.

In short, there must be a space before %, °C, and between Pg or Gt and C.

It is no trifle, as I reason in length, with apologies to bother you. If you know a better person to whom should I address my concern, please fw my letter accordingly.

In length, now:

Those rules are explained by NIST, there are serious arguments why they should be obeyed. In all documents, but mainly by such, which may influence millions of readers for many years.

I have decades of experience that writing quantitative expressions carelessly results in misunderstanding; it prevents people getting a proper knowledge of the issue.

Fortunately, there are not many kinds of such sloppy quantitative expressions in IPCC reports. They are easy to correct by a script (in html versions) or by an editor, just replacing several types of strings. No need to discuss it with authors or reviewers. Writing standards are nothing to struggle with.

A shortest possible introduction into proper writing of units etc. is


 - a checklist for editors.

So, several things to be corrected in AR5:

1) there is to be a space between a number and %
 -- see item 10 of the checklist or, in more length,

   (It continues by a paragraph recommending to avoid ppm, ppb and ppt,
 but I think their use is OK for concentrations; they are separated by
 space from the number in AR5 drafts, correctly, it is perhaps obvious
 that the  % sign has to be treated the same way.)

2) the same for degrees Celsius, for more reasoning see

3) PgC is a nightmare. No symbols of units are to be mixed with another stuff, see items 4 and 6 of the checklist, or
  http://physics.nist.gov/Pubs/SP811/sec07.html#7.4 and 7.5

So, please never write PgC or PgCO2. A space must be between the unit and a chemical symbol: Pg C, Pg CO2. The gram is always the same thing, there are no special grams for different stuffs.

(A similar mistake is "having" watts of electricity and heat, like We and Wt - if needed, the "W (e)" or "W (t)" can be written to distinguish between work and thermal flux.)

(As for Pg, I'd much prefer Gt, as fuels are sold rather by tons than by grams; giga is a much more common prefix than peta -- but of course, using petagrams is no mistake, just an obstacle for at least 90 % of readers. Kiloton, megaton, gigaton -- all are OK for NIST, unlike militon, and are accepted for use with the SI. Rejecting Gt in favour of Pg is, in my honest opinion, of no good. I will change Pg to Gt in translations, knowing no argument against.)

The whole NIST Special Publication 811 is available, as a single pdf or a html tree, at
and is worth while to study, for any authors and editors. Perhaps there is another document which may supersede the NIST one, but I don't know any. So I adhere to SP 811...

Actually, I mentioned it to some TSU of an IPCC special report already. A hint is the end of the English
 at my page with Czech versions of IPCC documents:

I understand that they may be reasons why NIST recommendations are not followed by IPCC - but in such a case, a document explaining them should exist, and a paragraph on conventions differing from NIST should precede any document which does not adhere to NIST fully.

yours sincerely,

Jenik Hollan, maintainer of a Czech electronic library on Climate Change,

Another thing which may be of interest for AR5, is making the glossaries
 hypertext. Like http://amper.ped.muni.cz/gw/ipcc_cz/glossary_i.htm or
 or a bilingual English-Czech ones, html or pdf, like
 -- it was a bit of programming to create it from the original, but I
think it was worth while. I hope I have the needed scripts somewhere, so
 that I would be able do the same for AR5.

 And, the glossaries should perhaps explain, what is understood by
 Earth System - like

                             Jan Hollan, Ph.D.

CzechGlobe - Global Change Research Centre of the Acad. Sci. Czech Rep.

AdMaS - Advanced Materials, Structures and Technologies Centre of the Brno University of Technology

Lipová 19, 602 00 Brno                         fix. +420 5 43 23 90 96
                            mob. +420 606 073 562

             volunteer of the Ecological Institute Veronica
Panská 9, 602 00 Brno, Czechia                  http://www.veronica.cz

e-mail: hollan@ped....cz              http://amper.ped.muni.cz/jenik