Prince Harry has defended his family's use of private jets and says he flies them 'to ensure his family are safe'.
The royal flew by commercial jet to Amsterdam today to make a speech marking the launch of a new environmental travel project.
The royal said in the speech that "no-one is perfect" and said people must balance out negative effects of global travel.
He and wife Meghan faced mounting criticism after reportedly taking four private jet journeys in 11 days during the summer.
He said :"I spend 99% of my life travelling the world by commercial.
"Occasionally there needs to be an opportunity based on a unique circumstance to ensure that my family are safe."
He says with 'Travalyst' he hopes to encourage people to make 'more environmentally friendly choices' when they travel.
Harry has spent three years working on the initiative, called Travalyst, which he hopes will improve conservation, environmental protection and help increase the economic benefits from tourism for local communities.
The duke and the co-founders of the project - Booking.com , Ctrip, Skyscanner, TripAdvisor and Visa - hope to spark a movement of like-minded companies and organisations to transform the future of travel into a more sustainable one.
Harry said in a speech to launch the initiative at Amsterdam's A'dam Tower: "What is clear across this vast landscape is that our world faces environmental challenges of unprecedented scope and scale.
"From deforestation and the loss of biodiversity, to ocean plastics and poaching, the problems can sometimes seem too big to fix.
"These human-caused challenges often need a giant system shift to make a significant enough impact. And that is what this partnership is here to try and do.
"Sometimes the scale of the conservation crisis feels overwhelming and that individual actions can't make a difference.
"I've certainly felt that - but I've learned that we cannot dismiss the idea of trying to do something, just because we can't do everything. We can all do better.
"And, while no-one is perfect, we are all responsible for our own individual impact; the question is what we do to balance it out."
Earlier today it was reported that a Hollywood PR firm, whose clients have included Michael Jackson and Harvey Weinstein, was enlisted to launch the Travalyst project.
Sunshine Sachs will not represent the pair in a personal capacity but the move has been dubbed "unorthodox" by royal insiders.
