Abstract
This paper is a report on the viability, both technical and ethical, of negative emissions technologies (NETs) in climate change mitigation. Given present levels of atmospheric carbon dioxide, NETs are almost certainly required in order to avoid the most serious consequences of anthropogenic carbonization. Critics argue that we should not rely on the promise of future NETs because that could be taken as an excuse to avoid decarbonization in the near term. The concern is genuine, but if the prima facie arguments for drawing down carbon as soon as possible are correct, ways must be found to counter the incentives to defer the immediate deployment of NETs and other forms of mitigation. A policy instrument is sketched which could help accomplish that task.