This brief final chapter offers some closing observations concerning solar geoengineering. Environmentalism is a diverse domain of thought, and its central norms – such as whether humans’ ideal role is treading as lightly as possible or being stewards of managed nature – are sometimes in tension. Solar geoengineering lies, in many ways, astride this division and its controversy should not be surprising. Yet my central concern is that the solar geoengineering discourse is unduly driven by intuition and ideology instead of empiricism and rationality. The seeming neglect and possible dismissal of solar geoengineering is a gamble that emissions abatement, adaptation, and negative emissions technologies will be sufficient to prevent dangerous climate change. Given the stakes, solar geoengineering should be taken seriously, including through governance that facilitates its responsible research, development, and – if warranted – use.