Reflecting on 50 years of geoengineering research

Earth's Future invited "leading experts in the field of geoengineering research to contribute brief reflections (2-5 pages) on the development of the discussion over the past decade and to consider where it may be going in the next 10 years." Responding to this request, we offer the following text in the spirit of reflections that emphasize our personal roles and viewpoints. The primary focus of many of our comments is solar geoengineering and not carbon dioxide removal (CDR). Thus, this text is not intended to comprise a comprehensive review or set of carefully documented analyses. Our primary conclusion is that sustained progress in "geoengineering" research will depend on social and material support for experimental work that can provide the observational basis for improved modeling and analysis, and, potentially, development and deployment of systems that may help protect the environment and improve human well-being. Relevant issues, and potential future trajectories, for CDR technologies may differ dramatically from those for solar geoengineering technologies.