A new assessment by the UK’s Climate Change Committee could have implications for future travel between Britain and Spain, with the committee estimating that a return flight from London to Alicante could cost around £150 more by 2050 under a full “polluter pays” approach to aviation emissions.

The figure is a long-term modelling estimate rather than a new tax or fare increase. It assumes airlines pass the costs of decarbonising aviation on to passengers.

The £150 Figure Comes From a 2050 Climate Scenario

The Climate Change Committee published its advice to the UK government on 16 September 2026 as part of the ongoing debate over the proposed expansion of Heathrow Airport.

In its Net Zero aviation pathway, the committee estimates that the cost of a return ticket from London to Alicante could increase by around £150 by 2050.

The same modelling estimates an increase of around £400 for a return trip from London to New York.

The figures represent the additional cost associated with measures needed to bring aviation emissions to net zero under the committee’s model. They are not forecasts of the actual retail price of flights in 2050.

Alicante Is the Specific Spanish Example

The £150 figure is specifically based on a return journey between London and Alicante.

It should not be interpreted as a blanket £150 increase on every flight from the UK to Spain. The final price impact of future climate policies would vary according to the route, aircraft, fuel use, distance, airline costs and the policies eventually adopted.

The Climate Change Committee also stresses that future ticket prices and household incomes are uncertain.

Airlines Would Be Expected to Pay the Decarbonisation Costs

The committee is calling for aviation to follow the “polluter pays” principle.

Under its proposed pathway, airlines and the wider aviation industry would bear the costs associated with measures such as sustainable aviation fuel and engineered carbon removals.

The committee says those costs would be reflected in ticket prices, helping both to finance emissions reductions and to manage growth in demand for flying.

It estimates the effect would amount to around 6 to 9 pence per mile.

Heathrow Expansion Is at the Centre of the Debate

The advice was requested by the UK government in connection with the proposed expansion of Heathrow Airport through a new Northwest Runway.

The Climate Change Committee says Heathrow expansion cannot currently be considered compatible with the UK's climate commitments unless the aviation industry is required to address its emissions by 2050.

According to the committee, aviation emissions under current government policy would still be higher in 2050 than in 2025, even without the Heathrow expansion.

The committee estimates that the full proposed Heathrow expansion would add 4.5 million tonnes of carbon dioxide equivalent emissions when completed in 2054.

No Heathrow Third Runway Has Been Approved

Despite the debate surrounding the project, Heathrow’s third runway has not been given final planning approval.

The UK government published a draft Heathrow Expansion National Policy Statement in June 2026 and opened it to consultation. The document provides the framework against which a future expansion application would be assessed.

The government has said the expansion should only proceed if it meets its requirements on economic growth, climate change, air quality and noise.

Parliamentary scrutiny of the draft policy is scheduled to continue until 26 November 2026.

The Government Has Yet to Decide on the Recommendations

The Climate Change Committee is an independent statutory adviser. Its recommendations are not automatically law.

The UK government will need to decide how, or whether, to implement the committee’s proposed approach to aviation emissions and ticket costs.

The committee is also calling for a long-term aviation policy framework to be set out in the revised Jet Zero Strategy planned for 2027.

Sustainable Aviation Fuel Will Be Part of the Transition

The committee says aviation will need a combination of measures to reach net zero.

These include improvements in aircraft and operational efficiency, sustainable aviation fuel, management of demand growth and engineered carbon removals for emissions that remain.

The committee's modelling assumes that industry would pay for the sustainable aviation fuel and engineered removals required under its pathway.

The UK already has policies designed to increase the use of sustainable aviation fuel, with the government's wider aviation strategy targeting further growth in the coming years.

Airlines Have Raised Concerns About Higher Fares

Airline representatives have criticised the potential effect of the proposed approach on passengers.

Airlines UK said the committee's approach could add considerably more to the cost of family holidays once multiple passengers are included. The organisation argues that investment in affordable sustainable aviation fuel, airspace reform and carbon-removal technologies should be prioritised instead.

Those comments represent the industry's position and are separate from the Climate Change Committee's modelling.

What This Could Mean for UK-Spain Travel

For people travelling between Britain and Spain, the Alicante example provides an indication of the possible long-term effect of aviation decarbonisation policies.

It does not mean that flights to Spain are about to become £150 more expensive.

The estimate applies to a specific 2050 scenario and assumes the full additional costs are passed on to passengers. Future fares will also depend on technology, fuel prices, airline economics, taxes, demand and any policies ultimately adopted by governments.

For now, the figure is best understood as a warning of the potential long-term cost of making aviation compatible with the UK's 2050 net zero target, rather than an immediate change to the price of flights between the UK and Spain.