The commuting home-work trips is an important contributor of the Greenhouses Gases (GHG) emissions of cities. In the campus “cité scientifique” of University of Lille, the commuting trips represent more than 50% of the total GHG emission. But during the pandemic, working at home change lead to significantly reduce these daily trips. At first sight, teleworking seems a valuable mean to cut these emissions by working at home and avoiding home-work trips. However, it requires new tools, such as videoconference, which also lead to indirect GHG emissions. In this paper, the GHG of a small research group on electro-mobility has been analyzed before and during the lockdown. From this case study, the GHG benefit depends on the daily commuting distance and the transport mean. For example, a person with 10-km daily trip using subway will increase its GHG emission by teleworking.