Earth system interventions (ESIs)—intentional large-scale interventions in Earth systems—are not entirely new. However, in response to threats to sustainability, particularly from climate change and biodiversity loss, some scientists and others are researching, developing, and using new, largely technological ESIs. These include carbon dioxide removal, solar geoengineering, in situ genetically modified organisms, gene drive organisms, de-extinction, and high-tech ecosystem restoration. Some emerging ESIs appear to be effective and feasible, both technically and economically, and may be necessary to achieve important sustainability and human welfare objectives. They also pose serious environmental risks. This paper identifies more than a dozen social, political, and ethical challenges that are common across many of the emerging technological ESIs. Governance could mitigate and manage these issues, and it would be made more effective and robust by understanding and treating new ESIs as such and as a potentially transformative set of innovations in human-Earth system relations.