Flying your Learjet up to Nova Scotia to see a total eclipse of the sun might have been held up as the ultimate in celebrity vanity by Carly Simon, but today’s celebrities, while no less vain, have their carbon footprint to think of.

When Prince Harry and Megan have been forced to defend their private jetsetting, and a schoolgirl is thumbing a low-carbon lift across the Atlantic by boat to highlight the climate emergency, the emissions associated with this most luxurious – and least necessary – form of travel look increasingly unjustifiable. Now, Labour is exploring plans to curb or ban their use.

Private jets produce many times more carbon per passenger than economy flights, not least because about 40% of trips are empty return legs.

The private jet industry itself is belatedly aware of how bad this looks. “We know that passengers are increasingly demanding to be transported sustainably,” says a spokesperson for the European Business Aviation Association (EBAA). “For decades, our sector has taken its environmental responsibilities very seriously. [We are] keen to be part of a sensible solution that balances the demand for travel, regional cohesion and economic growth with environmental and social responsibility.”

The carbon footprint of the sector has been cut by 40% in 40 years, with targets to halve emissions by mid-century, compared with 2005 levels. Future technology improvements include electric planes and novel fuels, such as those made from plants or waste products.

But the main argument defending private jets is that they make up such a small part of the climate problem – the EBAA claims private jets are responsible for 2% of civil aviation emissions, which itself is responsible for 2% of global greenhouse gas emissions, so 0.04% of emissions globally. With the industry trying to cut that further, surely celebrities and top businesspeople could be cut a little slack?

Private jet use is growing, however, as the billionaire class burgeons and the rest of us are squeezed. A report by Common Wealth found 142,000 flights from the UK on private jets last year, with the vast majority – 128,000 – short hops within Europe. While representing only 6% of UK air traffic, they produce the same carbon as about 450,000 cars a year.

For green campaigners, excuses about the tiny amount of emissions private jetsetters represent are growing thin. “These massively costly journeys are on the rise so it’s not good enough to dismiss them as statistically inconsequential – they just can’t be justified,” says Mel Evans of Greenpeace. While ordinary people are making efforts to cut their emissions, the super-rich are “undermining all that good work by blitzing through huge amounts of fuel on enormously inefficient journeys. A ban on fossil-fuelled private jets takes the challenge of fighting climate change caused by aviation to the people taking the most flights.”