ADEME emission factors (Base Empreinte) include direct CO2 and non-CO2 effects (contrails, nitrogen oxides). The calculation multiplies distance by the emission factor per passenger-km, meaning 225 gCO2e for short-haul and 178 gCO2e for long-haul. A calculator such as DGAC's or ADEME's provides the result in a few clicks.
Read the source article: Flight carbon footprint: the figures by destination