This internal report aims to develop an analytical review of reasons found in the literature on geoengineering.As the Royal Society [defines it, geoengineering (also called Earth’s system engineering, climate engineering, etc.) is “the deliberate large-scale manipulation of the planetary environment to counteract anthropogenic climate change”. This is mainly divided into two general categories: Solar Radiation Modification (SRM) and Carbon Dioxide Removal (CDR). “SRM” is an umbrella term that refers to interventions such as Stratospheric Aerosol Injection (SAI), Marine Cloud Brightening (MCB), Cirrus Cloud Thinning (CCT), and Space Mirrors (SM). These techniques seek to increase the reflection of incoming sunlight back to space in order to counter greenhouse gas concentrations, even though they differ in levels of scientific development, costs, risks, and the assessment of potential benefits. SAI is one of the most studied SRM technologies. It involves introducing aerosols (or gases that lead to aerosol formation) into the stratosphere, –which begins at different altitudes depending on the region of the planet (high latitudes or tropics)– to reflect a portion of incoming sunlight back into space.2 In this internal report, we provide an overview of arguments against geoengineering (section 3) to better assess the situation and risks, and an overview of arguments in favor of it (section 4) to better understand the debate as a whole. In the Conclusions (section 5), we present our closing remarks and a graphical mapping of the arguments. Ultimately, we also present two argument reconstructions in Appendix A (6).

This is a work-in-progress internal draft report from the research project FPCW-PR01-P016 Ethics and Governance of Earth Cooling Research: From concepts to implementation, funded by ARIA. Please contact ignaciomastro@gmail.com for the latest version.