The idea of a national climate service in or led by NOAA has received considerable attention in recent years. As of this writing, there is no agreed description of the purview, mandate, or organizational location of such a service. Yet it is clear that any form of national climate service should implement the principles of effective decision support. Thus, it should develop decision support products by means of communication between information providers and users that is likely to shape research agendas in ways that yield useful and usable research products. If a national climate service is created, it should be part of the decision support initiative we recommend and be closely linked to its research element. We believe that a national climate service located in a single agency and modeled on the weather service would by itself be less than fully effective for meeting the national needs for climate-related decision support.¹