Greta Thunberg’s trans-Atlantic voyage in a ‘zero-carbon yacht’ has been rocked by revelations that crew will fly to New York in a gas-guzzling plane to bring the boat back to Europe.

It is claimed that this would generate more emissions than the yacht saves and threatens to leave the 16-year-old’s plans to chart an environmentally friendly route to the United States in tatters.

On Wednesday, the Swedish eco-campaigner left Plymouth on the Malizia II for a two-week journey to the United Nations headquarters where she will address a climate change meeting.