How to assess the carbon footprint of a large-scale physics project

Large-scale experiments are building blocks of the physics community: they involve a large fraction scientific staff working in multiple countries, and absorb significant volume science budget. They also collection carbon-emitting sources practices. As such, it is essential to assess their environmental impact. We describe here methodology estimate main greenhouse gas (GHG) emissions large-scale astrophysics collaboration project, using transparent open data. The goal neither consider all possible emission nor calculate accurate values. It rather identify biggest obtain orders magnitude for them analyse relative weights. discuss methods quantify GHG-generating activities related factors three typical that can be controlled by collaboration: travel, digital hardware.