Solar geoengineering (SG) is a set of highly controversial emerging technologies proposed to address climate change by reflecting sunlight away from the planet to reduce temperatures. SG may reduce climate risks, however it also presents novel risks, uncertainties, and challenges, necessitating broad and inclusive public engagement. This Element presents a briefing book and methods toolkit to build capacity for public engagement on SG. Part I of the Element explains the need to build capacity to enable public engagement on solar geoengineering, and presents three methods for doing so: capacity building workshops, participatory Technology Assessment, and Deliberative Polling. Part II presents a briefing book that provides accessible, balanced, and evidence-based information on critical topics including climate science, climate policy, SG science, SG governance and policy, and SG ethics and justice. This title is also available as open access on Cambridge Core.