Translate the following English sentence to French:
"It should be introduced in such a way that the charge would be less for the unavoidable long haul journeys than it would for short flights for which there is a more environment-friendly alternative."
Il faudra la mettre en place de telle sorte qu' elle grève moins lourdement les vols long courrier, dont on ne peut pas se passer, que les vols sur de courtes distances pour lesquels existent des alternatives plus respectueuses de l' environnement.