Medium-haul flights are soaring – and it’s a problem for the planet

Last year, air travel returned to pre-pandemic levels. Passengers flying in and out of UK airports hit 300 million, almost exactly the same amount as 2019. Yet, provisional estimates suggest that the CO2 footprint of international aviation slightly increased . This is concerning. The government’s Jet Zero strategy hopes the aviation sector will deliver fuel efficiency improvements of 2% per year up to 2050. So why haven’t emissions gone down?

A major factor is our changing travel habits that see us flying further and further afield every year. According to NEF’s modelling, the average mileage of an international flight departing the UK has increased about 60 miles, or around 4%, since 2019. That may not sound much, but it’s enough to blow a big hole in our carbon budgets by 2050.

Below we can see the changes in where UK passengers flew between 2019 and 2024. The trend is clear. The biggest winner was Turkey, which saw a rise in transfer passengers and extraordinary growth in tourism at Dalaman and Antalya airports. Looking down the list you see how passengers have swapped nearby western European destinations for ​“medium-haul” destinations in north Africa (Morocco, Egypt, Canary Islands) and eastern Europe (Albania, Greece, Turkey). These are all flights in the 3 – 5 hours range. Saudi Arabia (6 hours) has also been working hard to develop itself as a tourist attraction.

Of course, some caution should be applied when interpreting this data. For example, you can see the impact of world events such as the decline in flights to Russia and Israel.

Table 1: Top ten international destination countries ranked by the increase/​decrease in annual passenger numbers over the period 2019 – 2024

Source: NEF analysis of Civil Aviation Authority (CAA) Airport data

As well as increasing overall emissions, the growth of ​“medium-haul” leisure is concerning because of its interaction with carbon tax policy. Many of the destinations seeing declines are within the EU/​UK Emissions Trading Scheme, meaning that a price is levied on carbon emissions. Many of the new flights are outside that scheme, so no price is paid. The difference this creates in the ticket price could actually encourage people to fly further, and therefore do more damage to the climate. Indeed, our analysis suggests overall between 2019 and 2024, passengers on routes to ETS-covered destinations declined by 3%, while passengers on routes to non-ETS destinations increased 8%.

Right now, the impact of the ETS on tickets is likely only £5 – 6 on a return flight, but changes are coming over the horizon which could significantly increase this. Free carbon allowances to airlines are expected to end next year, and we could see the effective carbon price rise to £12 – 14. Meanwhile, ETS prices are expected to rise, mainly because the fundamental principle of the scheme is that the pool of emissions allowances shrinks over time. The government’s recent commitment to re-align the UK with the EU scheme – where prices are currently about 50% higher – could also have an impact. Further rises will just make further away destinations more attractive.

In the first four month of 2025, compared with the same period in 2024, we can already see the aviation sector’s climate problem getting rapidly worse. So far there’s been a 4% rise in passenger numbers in just 12 months, a rate of increase sufficient to wipe out all the carbon savings made from efficiency gains and more. As shown below, the increase is driven by further rises in flights to leisure destinations in Saudi Arabia, Morocco, Tunisia, and Egypt. We can also see a rise in travel to India — likely due to the UK swapping EU migrant workers for South Asian after Brexit. So far this year we’ve seen growth in passenger numbers to ETS destinations (+2.8%) outpaced by growth to non-ETS destinations (+5.3%). This means an increasing number of passenger and airlines are paying effectively nothing for their climate damage.

Table 2: Top ten destination airports ranked by the proportionate increase/​decrease in passenger numbers over the period Jan-Apr 2024 to Jan-Apr 2025 (smaller destinations with less than 100,000 passengers are excluded, this leaves a total of 150 destinations).

Source: NEF analysis of Civil Aviation Authority (CAA) Airport data

As I said to parliament’s environmental audit committee this week, the perverse price incentive encouraging more environmentally damaging travel must be closed as soon as possible. Read our new report for some ideas on how we might do that.

Image: iStock