ABSTRACTThis article offers a constructive critique of the Oxford Principles for the governance of geoengineering and proposes an alternative set of principles, the Tollgate Principles, based on that critique. Our main concern is that, despite their many merits, the Oxford Principles remain largely instrumental and dominated by procedural considerations; therefore, they fail to lay the groundwork sufficiently for the more substantive ethical debate that is needed. The article aims to address this gap by making explicit many of the important ethical (...) questions lurking in the background, especially around values such as justice, respect and legitimacy. (shrink)