As the world continues to fail to reduce and control global surface temperatures, the use of solar radiation management (SRM) technology by one actor or by a small coalition of actors is becoming increasingly likely. Yet, most of the social scientific literature on solar geoengineering does not tend to systematically engage with this possibility; scholars focus either on global governance, or on banning SRM usage and research altogether. On the margins of this debate, a handful of researchers have sought to bring insights from the just war tradition to the issue of uni- and mini-lateral SRM usage. This article is concerned with the contribution just war/securitization theories can make to our understanding of the debate surrounding climate engineering. It scrutinises and deepens existing attempts by just war scholars to examine the moral permissibility of uni-lateral and mini-lateral SRM usage, including from the perspective of Just Securitization Theory.