We could start by requiring airlines to post an accurate individualized climate impact estimate when shopping for flights and on each passenger tickets. 

Hawaiian airlines, sponsor of the Malama Honua voyage of sustainability, could start doing this voluntarily as other airlines do. 

The WWV itself could start posting estimates of the climate impact of flying crew teams back and forth from Hawaii to ports around the world.

In other words, start by being transparent.

Local journalists could start leading the way by asking tough questions and raising awareness of the issue.