The Institute of Information Systems has launched a research project that combines findings from green information systems (GreenIS) and digital decision making (nudging). The project examines decision making in digital environments, or more specifically, sustainable decision making in online flight booking processes. Specifically, drawing on findings from behavioral science, the project analyses how small modifications to Web site design (i.e., nudges such as setting defaults) influence users’ behavior. The objectives of the project are (1) to identify nudges that might be used in designing online booking platforms to promote sustainable behavior, such as increasing offset payments when booking flights, (2) to explain how these nudges work, and (3) to test the effectiveness of these nudges through online and field experiments.