Research ArticleSCIENCE POLICY

A multistage crucible of revision and approval shapes IPCC policymaker summaries

See allHide authors and affiliations

Science Advances  05 Aug 2016:
Vol. 2, no. 8, e1600421
DOI: 10.1126/sciadv.1600421
  • Fig. 1 Overall, IPCC SPMs generally expand following revisions associated with governmental review and approval.

    (A) For the SPMs (WGI, WGII, WGIII, and SYR) of two IPCC assessment reports (AR4 and AR5), word length increases in all cases. (B and C) The number of figures (B) and tables (C) increases for many but not all SPMs. In each panel, the government review draft is the SPM draft circulated to IPCC member governments for written government review comments. The subsequent author-revised draft (shown only for the WGII AR5 SPM) is developed in advance of the plenary session in which IPCC member governments approve the SPM. The final SPM is the approved SPM, which includes further revisions from the plenary session as well as final production (that is, layout and minor copyediting). Words associated with figures and tables are not included in totals in (A). The percentage increase in word length, from government review draft to final SPM, is shown for each SPM in (A). For the WGII AR5 SPM, the percentage increase from the government review draft to the author revision draft (13%) is also listed.

  • Fig. 2 Individual IPCC SPM paragraphs differentially grow and shrink across SPMs, following revisions associated with governmental review and approval.

    For the SPMs (WGI, WGII, WGIII, and SYR) of two IPCC assessment reports (AR4 and AR5), net word changes are shown for different paragraph revision categories, comparing individual paragraphs in the government review draft to their counterparts in the final SPM. The paragraph revision categories are defined as follows: paragraphs that expanded, paragraphs that were newly added, paragraphs for which material was rearranged given splitting and/or merging of paragraphs, paragraphs that contracted, and paragraphs that were deleted. For each SPM, F is the sum of words deleted divided by the sum of words added. Words associated with figures and tables are not included in depicted net word changes.

  • Fig. 3 Author revisions, rather than plenary revisions, dominate IPCC WGII AR5 SPM changes associated with governmental review and approval.

    We assign two purposes to each revision in the WGII AR5 SPM, spanning text, figures, and tables (see data file S1). Table S1 describes the 11 revision-purpose categories. (A) Distribution of revision purposes for the 886 total revisions in the SPM, comparing the government review draft to the final SPM. (B) Distribution of revision purposes for the 598 author revisions introduced in full or in part in the author-revised draft developed in advance of the government-approval plenary session. (C) Distribution of revision purposes for the additional 288 plenary revisions made during the plenary session. For each panel, the percentage of purposes in each revision category is indicated at the end of each bar. For 136 revisions, a single revision purpose fully characterizes the revision. The corresponding purpose designation of “no secondary purpose” [136 for (A), 107 for (B), and 29 for (C)] is not plotted within the figure. Of the total revisions (A), 67.5% were author revisions (B) and 32.5% were plenary revisions (C).

  • Fig. 4 Author and plenary revisions in the IPCC WGII AR5 SPM emphasize different purposes.

    Each revision in the SPM is assigned two purposes (see data file S1). For each revision-purpose category (defined in table S1), this figure shows the proportion of purposes made as author versus plenary revisions. Author revisions were introduced in full or in part in the author-revised SPM draft developed in advance of the governmental-approval plenary session. Plenary revisions were made during the plenary session. The number of purposes in each revision category and stage is indicated at the end of each bar.

  • Fig. 5 IPCC SPMs become more and less readable through governmental review and approval across linguistic reading-ease metrics.

    (A to F) For the SPMs (WGI, WGII, WGIII, and SYR) of two IPCC assessment reports (AR4 and AR5), six reading-ease metrics are plotted for the government review draft versus the final SPM. For each metric, higher values correspond to greater reading ease. SPM values falling above each plot’s diagonal line indicate increased readability for the metric in the final SPM as compared to the government review draft; values below the diagonal line indicate decreased readability for the metric. (A) Flesch Reading Ease is a simple metric of text ease, calculated as a function of sentence and word length. (B to F) Coh-Metrix metrics characterize multiple dimensions of text ease. (B) High values of narrativity indicate text that communicates a story or sequence with familiar words, whereas low values reflect informational texts with unfamiliar words. (C) Higher values of syntactic simplicity indicate more simple, familiar syntactic structures and shorter sentences, whereas lower values correspond to structurally complex sentences. (D) Referential cohesion captures the extent to which words and ideas are explicitly connected across the text; higher values reflect more overlap in words and ideas. (E) Deep cohesion encompasses the use of connecting words that clarify relationships among events and concepts across the text; higher values correspond to greater use of connecting words. (F) Higher values of word concreteness indicate words that are more concrete, meaningful, and imaginable, as compared to abstract. Reference texts are assessment and report summaries in which scientist authors worked with input from professional editors to clarify text. Reference-text values are plotted along the diagonal in each panel.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/2/8/e1600421/DC1

    fig. S1. IPCC SPMs gain and lose figure panels through governmental review and approval.

    fig. S2. Revision purposes differ across IPCC WGII AR5 SPM text, figures, and tables.

    fig. S3. Revision purposes differ across IPCC WGII AR5 SPM paragraphs that grow versus those that shrink.

    table S1. Revisions to IPCC SPMs have different purposes.

    data file S1. Revisions to the IPCC WGII AR5 SPM emphasize different purposes; most revisions are author rather than plenary revisions.

  • Supplementary Materials

    This PDF file includes:

    • fig. S1. IPCC SPMs gain and lose figure panels through governmental review and approval.
    • fig. S2. Revision purposes differ across IPCC WGII AR5 SPM text, figures, and tables.
    • fig. S3. Revision purposes differ across IPCC WGII AR5 SPM paragraphs that grow versus those that shrink.
    • table S1. Revisions to IPCC SPMs have different purposes.
    • Legend for data file S1

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • data file S1 (Microsoft Excel format). Revisions to the IPCC WGII AR5 SPM emphasize different purposes; most revisions are author rather than plenary revisions.

    Files in this Data Supplement:

Stay Connected to Science Advances

Navigate This Article