It is quite amazing that Intergovernmental Panel on Climate Change experienced an urge for a guideline on the expression of uncertainty but failed to discover and acknowledge a broadly recognized and freely available international guideline on the subject. Here are links to the guideline developed by Intergovernmental Panel on Climate Change and the international guideline.
The guideline can be found here:
(Bureau International des Poids et Measures – Guides in metrology)
Please – have a look at the documents and make your own judgements. I would like to highlight the context in which each of these documents were made:
Here are some information on the context from the front cover of the IPCC guideline:
“IPCC Cross-Working Group Meeting on Consistent Treatment of Uncertainties Jasper Ridge, CA, USA 6-7 July 2010
The Guidance Note for Lead Authors of the IPCC Fifth Assessment Report on Consistent Treatment of Uncertainties is the agreed product of the IPCC Cross-Working Group Meeting on Consistent Treatment of Uncertainties.
This meeting was agreed in advance as part of the IPCC workplan. At its 32nd session, the IPCC Panel urged the implementation of this Guidance Note.
Supporting material prepared for consideration by the Intergovernmental Panel on Climate Change. This material has not been subjected to formal IPCC review processes.”
Now – you can compare with the preliminary (at page V) to Guide to the expression of Uncertainty in Measurement:
“This Guide establishes general rules for evaluating and expressing uncertainty in measurement that are intended to be applicable to a broad spectrum of measurements. The basis of the Guide is Recommendation 1 (CI-1981) of the Comité International des Poids et Mesures (CIPM) and Recommendation INC-1 (1980) of the Working Group on the Statement of Uncertainties. The Working Group was convened by the Bureau International des Poids et Mesures (BIPM) in response to a request of the CIPM. The ClPM Recommendation is the only recommendation concerning the expression of uncertainty in measurement adopted by an intergovernmental organization.
This Guide was prepared by a joint working group consisting of experts nominated by the BIPM, the International Electrotechnical Commission (IEC), the International Organization for Standardization (ISO), and the International Organization of Legal Metrology (OIML).
The following seven organizations* supported the development of this Guide, which is published in their name:
BIPM: Bureau International des Poids et Measures
IEC: International Electrotechnical Commission
IFCC: International Federation of Clinical Chemistry **
ISO: International Organization for Standardization
IUPAC: International Union of Pure and Applied Chemistry
IUPAP: International Union of Pure and Applied Physics
OlML: International Organization of Legal Metrology ”