ABSTRACT
Assessments of geoengineering have so far largely taken place under two dominant problem definitions. First, those efforts to reduce greenhouse gas emissions will not be enough to tackle climate change. Second, that as a result of this, we may be faced with a dangerous change in climate, often stylised as crossing one or more "tipping points"–a "climate emergency". The expert multi-criteria assessment conducted for the Royal Society's seminal report provides a valuable illustration of how framing geoengineering assessment through the selection and elevation of particular criteria can compel particular outcomes. These permutations demonstrate how different instrumental framings can serve to "close down" on certain geoengineering proposals. Broadening out and opening up geoengineering assessment reveals the complexities and uncertainties that are often reduced and hidden in narrowly framed assessments. Indeed, a remarkable level of consistency has been found across expert, stakeholder, and public perspectives, with geoengineering proposals being outperformed by mitigation alternatives.
