A post-Covid-19 world will see international flight prices skyrocket due to environmental concerns and caps on people entering major cities, according to industry experts.

The spike in price will likely come from the growing environmental impact of jet airliners and the tourism industry as well as major cities expecting to limit visitor numbers.

Former American Airlines boss Robert Crandall made the grim predictions at the CAPA Centre for Aviation forum.

“(The pandemic) has certainly up to this point been a watershed for the cruise business, and now you’ve got places like Venice and Rome saying ‘wait a minute, maybe we don’t want every traveller in the world to come here’,” Mr Crandall said, The Australian reported.

“We are going to see limitations of that kind and we are going to see more and more people worrying about the environment.”

Last year residents of Venice posted photos of crystal clear waters in its world-famous canals due to a lack of debris from tourists and near-zero boat traffic due to Italy’s coronavirus lockdown.

Dolphins were also spotted hunting for cuttlefish at the entrance of Venice’s Grand Canal in a very rare occurrence. Experts say they were likely drawn to the calmer waters due to the abundance of fish and lack of cruise ships and tourist boats in Venice during the pandemic.

Mr Crandall said that until recently, travel and tourism had been regard as “unmitigated good” but that was changing as more people learned about the industry’s environmental impact.

“There’s this conflict between what we have to do to safeguard the environment and what we would like to do in a whole variety of areas including travel,” he said.

“Maybe the average citizen can only take one trip by aeroplane because that’s all the CO2 we can allow transport to burn. We’ve got to control the climate, and we’ve got to control the rate at which we are using and destroying the world’s resources.”

Post-Covid-19 private jets and charter flights were tipped to become more attractive to travellers wanting to avoid crowded airports and the predicted inflexibility of commercial flight schedules.