In this talk I will differentiate two distinct yet interelated challenges: communicating the insights of science to enhance public and policymaker understanding of the facts, and improve their decisionmaking; and helping people and organizations change their behavior -- incuding adopting policies -- should they decide that doing so is in their best interest. I will also offer two simple guiding "heustics" (organizing devices), one that addressese the communication challenge, and one that address the behavior change challenge. Each of these heuristics is based in decades of social and behavioral science theory and empirical evidence, yet each is easily enough understood and implemented to be of value to individual scientists, science societies (like AMS) and other science organizations (like NOAA and CDC). The organizing heurstic for improving communication effectiveness is: simple clear messages, repeated often, by a variety of trusted sources. The organizing heuristic for improving the effectiveness of behavior change initative is to make the behavior being promoted: easy, fun and popular. I will give examples of both approaches drawn from my own work on climate change.