This chapter examines the ways in which uncertainties surrounding sea-level rise can, but may not, delay coastal adaptation action and how scientists can work more effectively with coastal practitioners and communities to make uncertainties intelligible and decision-relevant while still facilitating action. When scientific uncertainty is believed to be the reason for delayed decision-making, it must be reduced to get to action. An alternative paradigm offered here aims to more adequately capture the role of (uncertain) science in decision-making. It shows how scientific uncertainty is transmuted in the political process into political certainty so that it can bolster the case for action or inaction, as the case may be. In this sense, uncertainty becomes politically constructed. Scientists are not powerless bystanders to this process but can actively help co-construct the meaning, importance, and interpretation of both scientific and values uncertainties. This shifts the attention from “doing more science” to support decision-makers to “working more effectively at the science-policy interface.”