🙂 I just remembered that there is a database with finished master thesis called EPSILON:
https://stud.epsilon.slu.se/cgi/search/advanced
You just need to click the Environmental Communication box and search. It may help you to see what graduated students did research about. I was taking a look at the theses right now because I am super lost with how to start approaching mine.
One thesis particularly caught my attention: ” Snippe, Jara, 2017. To fly or not to fly: analysing interpretive repertoires to negotiate air travel among individuals working for an environmental NGO in Sweden.” I remember that when I volunteered in an environmental NGO in Spain, some people flought to the COP in Cancun, organized events which involved flying… and there was a debate around To fly or not to fly there too. Even here in Uppsala, among students, we discuss it. Some took action and stopped flying, some try to take the train more often and some feel guilty when booking flight tickets. It seems cool to me that it is possible to do research about these blurry issues… So, I recommend checking out the database.