Elton John has attacked the criticism of the use of private jets by the Duke and Duchess of Sussex – reportedly four journeys in 11 days – by saying he not only paid for the plane, but also paid to offset its giant carbon emissions. “We ensured their flight was carbon neutral,” he tweeted.

The world of carbon offsetting flights – where you can pay to have the equivalent of your emissions “cancelled out” by projects that lower or remove emissions, such as reforestation or renewable energy – is not clearcut. While some argue it is better than doing nothing, others say it allows frequent flyers to assuage their guilt and the aviation industry to grow.

“The idea that you can fly ‘carbon neutral’ is very misleading,” says Roger Tyers, a research fellow at the University of Southampton, who studies attitudes to offsetting and recently made a work trip to China by train. “A plane that flies today emits carbon today. It’s very hard to know how fast an offset can remove that amount of carbon from the atmosphere.”

It is possible to be appalled by the tone of the attacks on the couple, on Meghan especially, while wondering if the pair couldn’t have made better choices, given their influence and professed concern about the climate crisis. And where is the comparable fuss about the use in the past year of chartered planes by Prince Charles, who recently said global leaders must act within the next 18 months to avert climate catastrophe? In the past year, the royal family’s emissions from “business travel” have doubled.

All of us need to rethink our consumption of flights, not simply try to buy our way out with offsetting. Offsetting, says Tyers, is better than it was about a decade ago “when you had lots of stories about the money getting lost in the world of carbon finance. It’s much tighter now and money generally does go to [things like] reforestation projects.” However, he says, “it is questionable whether it will deliver what we need within the timescale necessary. And the cultural signal that it gives off – that you can have your cake and eat it – is problematic.”