Changing climate change: The carbon budget and the modifying-work of the IPCC

Abstract

Over the last 10 years, the concept of a global ‘carbon budget’ of allowable CO2 emissions has become ubiquitous in climate science and policy. Since it was brought to prominence by the Fifth Assessment Report of the IPCC, the carbon budget has changed how climate change is enacted as an issue of public concern, from determining the optimal rate of future emissions to establishing a fixed limit for how much emissions should be allowed before they must be stopped altogether. Exploring the emergence of the carbon budget concept, this article shows how the assessment process of the IPCC has offered scientific experts the means to modify how the climate issue is problematized, and discusses the implications of this ‘modifying-work’ for the politics of climate change. It finds that the ‘modified climate issue’ must be seen as an outcome of the ordinary work within established scientific and political institutions, and the agency these institutions afford scientists to enact the issue differently. On this basis, it argues that the case of the carbon budget holds important insights not only for the relationship between climate science and policy, but also for the pragmatist literature on ‘issue formation’ in STS.

Threshold, budget and deadline: beyond the discourse of climate scarcity and control

“…The concept of the remaining carbon budget emerged around 2009 from modelling studies on the climate and carbon cycle system (see Lahn 2020 ). But it was the release of the IPCC’s Fifth Assessment Report (AR5) in 2013–2014 that firmly enacted the carbon budget as a new, central concept for guiding the climate policy debate (Lahn 2021 ). As Lahn ( 2021 ) noted, the IPCC provided an institutional infrastructure that enabled the group of scientists who first developed this concept to present it to policymakers with authority and legitimacy.…”

“…But it was the release of the IPCC’s Fifth Assessment Report (AR5) in 2013–2014 that firmly enacted the carbon budget as a new, central concept for guiding the climate policy debate (Lahn 2021 ). As Lahn ( 2021 ) noted, the IPCC provided an institutional infrastructure that enabled the group of scientists who first developed this concept to present it to policymakers with authority and legitimacy. The iconic figure in the Synthesis Report (SYR) of AR5 clearly shows how the idea of the carbon budget became the focal point connecting the risk assessment of climate change impacts to the emissions projection of climate change mitigation (see Fig.…”

“…Following the publication of AR5, the concept of the remaining carbon budget has been used widely in public discourse, adopted especially as the scientific basis for new climate activism, such as fossil fuel divestment and climate school strike (Lahn 2021 ; Strauch et al 2020 ). For climate activists like Bill McKibben, 2 the remarkably small size of the remaining carbon budget for the 1.5°C or 2°C target means more than a mere estimate by the modelling.…”

The Discourse and Reality of Carbon Dioxide Removal: Toward the Responsible Use of Metaphors in Post-normal Times

“…Meanwhile, other metaphors operate in less overt ways by virtue of the more "neutral" comparison between the source and target domains. For instance, climate researchers have quite successfully introduced the notion of a "carbon budget" into global discussions about climate policy since around 2005 (see Lahn, 2020). In Anglophone popular culture, the word "budget" is less loaded than the word "negative."…”

The ambivalent role of environmental NGOs in climate communication

“…Climate change is only accessible via a comprehensive scientific, technical and institutional infrastructure which historian of science Paul Edwards has tellingly written about as "the vast machine" [Edwards, 2010]. The concept of dangerous anthropogenic climate change as a decade-long increase in average global temperature [Intergovernmental Panel on Climate Change, 2013], or, more recently, as overshooting a permissible global carbon budget [Lahn, 2020], is not something that individuals directly experience [Mormont and Dasnoy, 1995;Stehr and Storch, 1995]. Extreme weather or changes in vegetation or seasons can be experienced, yet climate is in place-based and culturally embedded ways socially constructed and linked to the scientific concept of climate change [Hulme, 2017;Hulme et al, 2009].…”