How can we make more transparent and lessen the struggle over concepts in IPCC assessment reports?

In a recent article, Hughes and Vadrot (2019) introduced the notion of a weighted concept to explore how political struggle in intergovernmental assessment bodies transposes on scientific objects through the government approval of the Summaries for Policymakers (SPMs). In this paper, we want to explore whether it is possible to scale the level of controversy a particular concept initiates or has the potential to initiate by looking at past struggles in the IPCC. There is now growing evidence that the most controversial objects in the IPCC approval process are those that relate to or have the potential to relate to negotiations within the UNFCCC, or that are simply (geo)politically ‘unacceptable’. As a result, tables, boxes and new scientific terms are often removed, made ambiguous or tightly defined in the text, which makes it increasingly difficult to introduce new scientific elements or challenge existing approaches that could contribute to the negotiations of climate change. Examples include emission reduction targets or budgets (Lahn and Sundqvist 2017; Lahn 2020), categorization of countries (Victor et al. 2014), ex post assessment of climate policies (Carraro et al. 2017) and legal terms bound to other international regimes (e.g. global commons). All of these triggered significant controversies in the IPCC, to the point of leading to self-censorship by authors in following assessment cycles. In this paper, we look at the social construction of controversial concepts, tables and boxes, at the (geo)political and legal interpretations that are derived from them, as well as at the governments/coalition of governments that condemn them to draw patterns of divisiveness. By unpacking this relationship and developing a scale approach to scientific content in the SPM we hope to be able to identify potential controversies and explore ways to dampen this through identification and commentary processes in the government review stage.