Carbon offsetting: How to reduce the impact of flying

Air travel has found itself at the centre of the debate on climate change.

There’s no denying that it’s carbon intensive: each passenger on a return flight from London to Singapore accounts for around three tonnes of CO2. That’s the equivalent of heating a family home for a year.

Flying less isn’t something everyone is able or willing to do. This has given rise to carbon offsetting schemes, which claim to balance out the environmental impact of your journey. 

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What is carbon offsetting?

The idea is that we voluntarily calculate the CO2 we’re responsible for, then fund a project that reduces emissions by the same amount. Popular schemes include tree planting, wind and solar farms and the distribution of fuel-efficient stoves in developing countries.

There are plenty of carbon calculators that ask you to input your flight route or an amount of CO2 (if you already have an estimate) to come up with an appropriate donation.

Around 2% of Which? members told us they always pay to offset their flights. That figure is actually higher than the national average of just 1%, according to the International Air Transport Association (IATA).

The problems with offsetting

There are many reasons why people aren’t buying into carbon offsetting schemes. Responsible Travel argues that to tackle climate change we must actively reduce our carbon footprint, rather than trying to ‘cancel out’ the damage afterwards.

On top of this, many environmental groups have argued that these schemes don’t actually work. For example, a newly-planted tree can take decades to capture and store a significant amount of CO2. And even then there is a very real risk that these efforts will be wiped out by drought, wildfires and deforestation.

The Advertising Standards Authority (ASA) also vowed to crackdown on misleading carbon offsetting claims amid growing concerns of greenwashing. It most recently banned ads from both Qatar Airways and Eurowings for suggesting that holidaymakers could travel climate-consciously by offsetting the carbon footprint of their flight.

The alternatives to carbon offsetting 

Many airlines have moved away from voluntary carbon offsetting schemes because of the controversy surrounding them and the lack of uptake from passengers.

But some airlines offer alternatives. For example, British Airways invites flyers to make a donation to the BA Better World Community Fund at the checkout; with the money going to charities and social enterprises that promote climate action, biodiversity and nature.

Customers can also purchase certified carbon removal credits through its climate platform CO₂llaborate. These differ from offsets in that they physically remove CO₂ from the atmosphere and store it durably for over 100 years. One scheme in Scotland captures CO2 emissions from whisky distilleries and repurposes it into building materials.  

Furthermore, members of the British Airways Club can earn tier points and Avios by making a contribution to the development and production of Sustainable Aviation Fuel (SAF).

What is Sustainable Aviation Fuel (SAF)?

SAFs emit as much carbon as fossil-based fuels in-flight. However, they’re considered more sustainable because they’re made from waste oils and fats, such as cooking oil and animal fats - essentially ‘recycling’ carbon already in circulation. 

The major challenge is that the availability of SAF remains very low: SAF production will only account for 0.8% of airline fuel use in 2026, according to IATA. 

This will have to be scaled up rapidly for the aviation industry to achieve its net-zero carbon emissions target by 2050.

If you still want to offset your flight

Those who want to offset their carbon emissions can go to reputable non-profit Atmosfair. Not all airlines are included in its flight calculator, but it also gives you the average carbon estimate for your route. 

If you have been given a CO2 estimate elsewhere, you can type the value into Atmosfair's 'offset a desired amount of CO2' calculator and make a one off payment. The money helps to fund various global projects, such as hydro power, solar energy and efficient cook stoves. Another reliable source is ICAO's calculator.  

How to choose the right carbon offsetting project

To make sure you choose an effective scheme, look for internationally recognised certification. VCS (Verified Carbon Standard) and Gold Standard are two you can trust.

A verified project will:

• Have no negative impact on local communities – eg displacement to make way for a new wind farm or tree-planting project
• Be monitored to make sure carbon reductions are achieved
• Do more than simply switch one fossil fuel for another.

The problems with offsetting

There are many reasons why people aren’t buying into carbon offsetting schemes. Responsible Travel argues that to tackle climate change we must actively reduce our carbon footprint, rather than trying to ‘cancel out’ the damage afterwards.

Sarah Leugers of the Gold Standard told Which? Travel: ‘Offsetting isn't the solution or the only thing we should be considering, but most of us can’t reduce our footprint to zero. Taking accountability for the remaining pollution is absolutely the right thing to do.’

Six ways to reduce your carbon footprint

1. Use a flight aggregator

Skyscanner’s search tool will highlight the greenest flight for your journey with a leaf motif, alongside the percentage of CO2 saved. Google Flights will also give you an estimate of your CO2 emissions in the search results. The Civil Aviation Authority (CAA) has advised that all airlines and booking sites should display clear carbon emissions data for flights from April 2027.

2. Fly economy

Business and first class are responsible for up to four times more CO₂ per passenger. See which carriers came top in our survey of best airlines.

3. Choose greener aircraft

Look out for newer, more fuel-efficient models, such as the Boeing 787-9 Dreamliner, Airbus A350-900, A320neo and A321neo.

4. Fly direct

Choose direct where possible. Taking off uses more fuel than cruising.

5. Pack light

A heavier plane also guzzles more fuel.

6. Take a train or ferry

The Eurostar emits around 90% less carbon than the equivalent flight. The reduction is similar for foot passengers who take the ferry.

Best rail holiday companies and ferries for 2026.