The Intergovernmental Panel on Climate Change suggests that, in addition to rapidly reducing CO 2 emissions, we will need to remove between 1.3-29 GtCO 2 from the atmosphere annually by 2050 to limit global warming to 1.5°C above pre-industrial temperatures. Carbon dioxide removal (CDR) encompasses a set of solutions that accomplishes this task by drawing down atmospheric CO 2 and durably storing it. Many CDR solutions, however, are not yet ready for large-scale deployment as there is significant uncertainty regarding their mechanics, cost, and broader impact. Further, deployment of these solutions may require long lead times that will need to be compressed in order to mitigate climate change on relevant time scales. Thus, this decade is a decisive period to test and develop CDR options that will eventually deliver the negative greenhouse gas (GHG) emissions required for climate stability.