Government Comments on the Final Draft of the SPM IPCC Working ...

<strong>Government</strong> <strong>Comments</strong> on the Final Draft of the SPM
IPCC Working Group I Fourth Assessment Report
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century temperatures may rise by between 1.0 and 6.3°C depending on emission scenarios and model uncertainty. The actual
warming will be significantly affected by the emissions of greenhouse gases that occur. Such warming will increase the
frequency of heat waves and heavy precipitation events, affect storminess and reduce snow and ice cover. (continuation
comments combined by TSU)
[Govt. of United Kingdom (Reviewer’s comment ID #: 2022-9)]
SPM-55 A 1:3 1:5 This opening sentence is awkward and long. The phrase “processes and attribution” is an unusual pairing of terms given the
more common "Detection and Attribution". Suggest instead “The WG1 contribution to the IPCC Fourth Assessment report
describes current scientific understanding of the dominant causes of climate change, of observed climate change and
attribution thereof, and of climate processes. A range of estimates for projected future climate are also presented. The report
builds upon…..”
[Govt. of Canada (Reviewer’s comment ID #: 2004-9)]
SPM-56 A 1:4 1:5 Suggest changing "dominant causes" to "driving factors" in order to avoid the confusion with "attribution".
[Govt. of China (Reviewer’s comment ID #: 2006-2)]
SPM-57 A 1:4 1:4 "..the dominant causes of climate change, observed climate change,..": I find this sentence confusing. Should this read instead
"..the dominant causes of observed climate change.."?
[Govt. of Italy (Reviewer’s comment ID #: 2012-8)]
SPM-58 A 1:4 1:4 Footnote 5 on likelihoods: Add: "These percentages are based on the authors’ collective, subjective expert judgement of
observations and model results"
[Govt. of Netherlands (Reviewer’s comment ID #: 2014-2)]
SPM-59 A 1:4 1:5 Delete “and attribution” because the sentence already mentions “dominant causes of climate change” which is essentially the
same thing, and “attribution” is jargon.
[Govt. of United States of America (Reviewer’s comment ID #: 2023-2)]
SPM-60 A 1:5 1:5 Either capitalize "assessments" or change to "Assessment Reports" to indicate that previous IPCC Assessment Reports are
what are being referred to here.
[Govt. of Japan (Reviewer’s comment ID #: 2013-2)]
SPM-61 A 1:5 1:6 Write :"It builds upon previous work of the IPCC and assess new results from the past six years of research and modelling."
[Govt. of Switzerland (Reviewer’s comment ID #: 2020-4)]
SPM-62 A 1:5 1:6 Delete last sentence of the first paragraph (“It builds … research.”) and insert the first two paragraphs of the Technical
Summary (TS-3, lines 3-17) as a more substantive introduction. Major points need to be on the first page, so highlight that
“likely” (TAR) has evolved to “very likely” (AR4) regarding attribution to human activities. Include the headline (SPM-8,
lines 23-24): “It is very likely that anthropogenic greenhouse gas increases caused most of the observed increase in globally
averaged temperatures since the mid-20th century” to the end of the first inserted TS paragraph. This increased confidence is
the bottom line.
Suggested inserted text follows:
“In the last 6 years since the IPCC’s Third Assessment Report (TAR), significant progress has been made in understanding
past and recent climate change and in projecting future changes. These advances have arisen from large amounts of new data,
more sophisticated analyses of data, improvements in the understanding and simulation of physical processes in climate
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