The amount is calculated on the basis of the carbon dioxide released as passengers are told how to fasten their seat belts, by "inserting the metal end into the buckle and pull the strap to tighten. To open, simply release the buckle by lifting on top" and so on.
As the flight attendant speaks, he or she breathes out carbon dioxide. According to Professor Wilhelm Anker, who conducted the research at the university's Centre for Research into Aerial Products, the calculation is a simple one - there are some 100,000 aircraft takeoffs each day and multiplying that number by the emissions on each flight, the amount quickly adds up.
It has now become a sizeable contribution to climate change.
There has been considerable debate about the need to explain to passengers how to do up their seatbelts, on the basis that if they don't know how to do it, they would be better occupied walking or using some other mode of transport. Or staying at home watching television.
Some put the shortcoming down to the erosion of useful education that students now receive in college. College principal Mr T. Eacher said "it is a sad indictment of the depths to which our educational system has sunk that students are able to graduate without having a clue how to fasten a seatbelt." And, he added, there are of course consequences: "now that the evidence is there of a direct link between the need to explain to people 10,000 times a day and climate change, it is time for a strenuous rethink of our educational system."
Asked whether this would affect the way airlines dealt with the issue, industry CEOs were reluctant to comment, citing the need to minimise their own carbon emissions; but one did explain that consideration was being given to establishing training courses for would-be passengers, to show how belts were fastened and unfastened.
Seatbelt manufacturers contacted for comment did not return our calls.