Fig. 11.

The graphical output of the online X-IFU travel footprint calculator run for the case of the X-ray Astronomy 2019. The X-IFU calculator ranks the cities according to their associated travel footprint. The minimum distance for flying is assumed to be 500 km. Travels from cities at the top of the plot above Geneva (included) are assumed to be done by train. The CO₂eq emission (summed over all the participants traveling from the given city) labels the green symbols on the plot (the number of travelers is not shown and the difference of emissions between two nearby cities is related to a different number travelers). The emission is computed from the mean of the ADEME, atmosfair, myclimate, and DEFRA estimates, assuming all passengers flew in economy class. The total emission from the meeting was ∼ 465 tons of CO₂eq, and for the audience of the meeting Bologna was close to the site of minimum emission. At the bottom of the figure, Cambridge refers to the city in the United States