A science-based understanding of climate change and potential mitigation and adaptation options can provide decision makers with important guidance in making decisions about how best to respond to the many challenges inherent in climate change. In this review we provide an evidence-based heuristic for guiding efforts to share science-based information about climate change with decision makers and the public at large. Well-informed decision makers are likely to make better decisions, but for a range of reasons, their inclinations to act on their decisions are not always realized into effective actions. We therefore also provide a second evidence-based heuristic for helping people and organizations change their climate change–relevant behaviors, should they decide to. These two guiding heuristics can help scientists and others harness the power of communication and behavior science in service of enhancing society’s response to climate change.