The world is wrought with risks that may harm people and cost lives. The news is riddled with reports of natural disasters (wildfires, floods, earthquakes, hurricanes), industrial disasters (chemical spills, water and air pollution), and health pandemics (e.g., SARS, H1NI, COVID19). Effective risk communication is critical to mitigating harms. The body of research in this handbook reveals the challenges of communicating such messages, affirms the need for dialogue, embraces the role of instruction in proactively communicating risk, acknowledges the function of competing risk messages,...