Greta Thunberg, the Swedish climate activist, opted to sail to the US from Europe this month, rather than catching a plane.  Her choice reflected a growing recognition that air travel carries a heavy cost to the environment. Sylvia Pfeifer, acting industry editor, discusses how airlines are responding to the challenge with Janina Conboye and Leslie Hook. Contributors: Sylvia Pfeifer, acting industry editor, Janina Conboye, industry reporter, and Leslie Hook, environment correspondent, Producer: Fiona Symon For information regarding your data privacy, visit acast.com/privacy