s. Whether it should be part of a global climate mitigation strategy, however, remains controversial. One of the key issues is that, contrary to emission abatement, carbon sequestration might not be permanent. But some argue that even temporary sequestration is beneficial as it delays climate change impacts and"buys"time for technical change in the energy sector. To rigorously assess these arguments, the authors build an international optimization model in which both sequestration and abatement can be used to mitigate climate change. They confirm that permanent sequestration, if feasible, can be overall part of a climate mitigation strategy. When permanence can be guaranteed, sequestration is equivalent to fossil-fuel emissions abatement. T...