This chapter explores the influence of guilt on air passengers' decisions to purchase voluntary carbon offset (VCO) programs. It examines how airlines' environmental messages, when framed effectively, can evoke guilt and encourage consumer engagement in offset programs. The study builds on theories of message framing, guilt, environmental attitude, and trust, proposing a model where guilt mediates the relationship between message framing and purchase behavior. Additionally, environmental attitude and trust are explored as moderators of guilt's influence. This chapter presents a theoretical model that explores the interaction between various factors influencing the effectiveness of message framing on the purchase of VCO programs. It provides insights into the impact of message framing on promoting sustainable behavior. Additionally, the chapter offers research avenues aimed at understanding how these framing strategies can effectively encourage passengers to engage in and purchase VCO programs, ultimately contributing to environmental sustainability literature in the aviation industry