The cost of direct air capture and storage can be reduced via strategic deployment but is unlikely to fall below stated cost targets

Carbon dioxide removal (CDR) is necessary to minimize the impact of climate change by tackling hard-toabate sectors and historical emissions. Direct air capture and storage (DACS) is an important CDR technology, but it remains unclear when and how DACS can be economically viable. Here, we use a bottom-up engineering-economic model together with top-down technological learning projections to calculate plant-level trajectories for four DACS technologies. Our analysis demonstrates that the costs of these technologies plateau by 2050 at around 100-600 t-CO2-1 mainly via capital cost reduction through aggressive deployment, but still exceed the optimistic targets defined by countries such as the US (i.e.,100 t-CO2-1). A further of existing policy mechanisms indicates that strong, project-catered policy support will be required create market opportunities, accelerate DACS scale-up and lower the costs further. Our work suggests strategic DACS deployment and operation must be coupled with strong policies to minimise the cost DACS and maximise the opportunity to make a planet-scale climate impact.