The willingness to make voluntary payments to offset carbon dioxide (CO2) emissions has increased significantly in recent years. One way to further increase this willingness to offset is to activate a social norm by drawing attention to the fact that offsetting emissions is socially desirable. With this in mind, this paper examines the willingness to offset CO2 emissions caused by air travel by purchasing carbon offsets using a discrete decision experiment embedded in a 2019 survey. A descriptive social norm was randomly assigned, as was one of three offset levels of 5, 10, or 15 C. The results show that 57.0% of subjects choose to offset emissions from a future upcoming flight. Here, only slight, statistically non-significant differences are found between the control group and the group that was confronted with a social norm.