On the SRM side of the toolbox, we are at an even earlier stage, so the go-forward imperative here is not development but simply research. We need a much more sound understanding as to whether and how these interventions might work and how we might domesticate them via thoughtful and inclusive governance. The SRM sibling to the National Academies report described above was issued in spring 2021. It recommends an expenditure of $100–200 million over five years, a small fraction of the proposed budget for CDR. Nonetheless, this would be a vast expansion of resources for the field. My personal path forward entails working with colleagues to design aircraft that could be useful in such research.