Aviation accounts for around 5% of global carbon emissions.
Your money is split equally between two environmental projects that help to withdraw carbon from the atmosphere.
This might be from an individual flight, but it could also be from driving your kids to school, say, or having your heating on all day.
Here’s how it now works if you’re using Manchester Airports Group.
Your flight causes carbon emissions, but your money is invested in projects that counter these emissions, cleaning your slate.
So when assessing the quality of a carbon offsetting scheme, it’s important to understand how quickly the emissions can be offset.
“The term itself suggests we’re able to cancel out the impacts of a flight – and, by that logic, fly as much as we like.
“The carbon market is divided between compliance and voluntary programs,” explains Sarah Leugers, director of communications at The Gold Standard, the climate interventions standards body.
Carbon offsetting schemes are accredited by third-party standards bodies, but while the Task Force for Scaling the Voluntary Carbon Market is currently trying to establish an independent governance body and “core carbon principles”, at the moment each of these organisations employs different standards.
“Individuals should only consider buying credits from internationally recognised standards,” says Ms Leugers.
If you’re imagining it’s just a lot of tree-planting, you’re mistaken.
“Some people are passionate about ecosystems and biodiversity and may wish to choose a land use project,” says Ms Leugers.
Some climate scientists and campaigners worry that carbon offsetting is being used simply as a fig leaf to cover over our continuing reliance on fossil fuels, when it’s our behaviour that needs to change.