1 BACKGROUND BRIEFING Geoengineering: issues of path-dependence and socio-technical lock-in Rose Cairns (SPRU – Science and Technology Policy Research) 1 Introduction In recent years there has been growing academic and policy interest in geoengineering – the large scale, intentional manipulation of climate system in order to attempt to counteract the effects of climate change (Belter & Seidel 2013). Alongside a number of other important policy issues, concerns have been raised over the potential for geoengineering technologies to contribute to so-called ‘carbon lock-in’ (Unruh 2000), or to become ‘locked-in’ themselves (CBD, 2012; Shepherd et al., 2009; Rayner et al., 2013). In particular, the scale of infrastructures that geoengineering interventions would require, and the issue of the so-called ‘termination effect’ (Jones et al. 2013) (whereby the termination of a programme of stratospheric aerosol injection would result in rapid heating of the planet) have been discussed in these terms. Dynamics of ‘lock-in’ have been raised even in relation to the more purely discursive aspects of these challenges, where (despite the emergent and somewhat ill-defined nature of the field), it has been suggested that the extant framings of geoengineering in academic and policy literatures may already demonstrate features recognisable as forms of cognitive lock-in, likely to have profound implications for future developments in this area (Bellamy et al. 2012). This review paper, prepared in advance of an academic and policy workshop on the topic, is intended to give participants a brief overview of the theoretical literature on lock-in and path-dependence, to summarise the ways in which these concepts have been invoked in the existing literature on geoengineering, to highlight some on-going theoretical debates around these concepts, and to examine the generic, and more geoengineering-specific challenges of assessment of these processes. 1 This briefing was prepared for participants in a workshop on the issues of path‐dependence and lock‐in as they relate to the field of geoengineering, held at UCL Faculty of Laws on Friday 25th October 2013. The workshop was organised as part of the Climate Geoengineering Governance project http://geoengineering‐governance‐research.org A version of this manuscript was submitted to the journal WIREs Climate Change in January 2014 and is currently under review. Other presentations from the workshop can be found in a special section of the outputs part of the CGG website.