How Much Does Flying Fuel Climate Change?

In 1960, air travel was a privilege, with just 28 airlines in operation. Over the next decade, most carriers retired their piston-powered fleets in favor of jets, speeding up flights and improving passenger comfort. The subsequent waves of deregulation and globalization turned flying into a mass-market activity. Today, more than 5,000 airlines operate over 100,000 commercial flights each day. 

Climate crunch time 

With global temperatures climbing faster than predicted and a new UN report declaring that the world faces a ‘climate crunch,’ should our infatuation with flying come to an end? A growing cadre of no-fly campaigners certainly think so. They urge travelers to reduce their carbon footprint by opting for alternative modes of transport. In Europe, travel operators specializing in flight-free vacations, like Byway, are creating a new market segment in response.  

Yet such behavioral change remains marginal. Despite mounting concern over the climate crisis, most travelers show little sign of altering their habits. In 2024, global flights were projected to reach 38.7 million, just shy of 2019’s pre-pandemic zenith of 38.9 million. The question is: to what extent does this matter?  

 A disproportionate contribution 

Aviation accounts for just 4% of global greenhouse gas emissions. —a modest figure at first glance. But context matters. A disproportionate share of these emissions comes from a small, privileged cohort of frequent flyers. In the United States, 12% of people account for 66% of all flights. In France, just 2% take half. China sees 5% of households responsible for 40% of flights, while in India, only 1% of households take 45%.  

With 80% to 90% of the global population never setting foot on a plane, aviation emissions are strikingly disproportionate. The bulk of these emissions come from affluent travelers, predominantly in the West, while the heaviest toll is borne by poorer communities in the Global South—those least responsible for the climate crisis yet most vulnerable to its effects.  

Climate injustice 

This disparity between who flies and who bears the environmental burden has made aviation a symbol of “climate injustice.” Geographically, the divide is evident in the higher emissions produced by wealthy nations compared with lower-income ones, but systemic social inequalities also exist within countries. For example, in the US, those living near polluting airports are likelier to be low-income communities exposed to harmful emissions. Meanwhile, wealthier, predominantly white demographics—who fly more frequently—are far less likely to endure such conditions. 

This imbalance seems likely to worsen. As the middle classes in countries like China and India grow, so will the demand for air travel, with international flights projected to rise by 60% by 2040. The International Civil Aviation Organization estimates that, by 2050, global aviation emissions could triple —intensifying the burden on the world’s poorest and most vulnerable. Adding to the problem is the increasing appetite of the ultra-rich for private jets. Between 2019 and 2023, private flights exceeded four million annually, driving a 46% surge in their emissions. 

 Climate commitments  

Aware of its sustainability challenge, the aviation industry has vowed to decarbonize. In 2021, the International Air Transport Association (IATA), representing roughly 300 airlines, adopted a resolution committing to net-zero carbon emissions by 2050—aligning with the Paris Agreement’s goal of limiting global warming to 1.5°C. Major carriers have since made similar pledges, including American Airlines, British Airways, Delta, Japan Airlines, Lufthansa, Qantas, and United. 

In practice, IATA claims that 65% of emission reductions will hinge on adopting sustainable aviation fuels (SAFs), 13% on new technologies such as electric and hydrogen-powered aircraft, and 3% on improvements in infrastructure and operations. The remaining 19% is expected to come from carbon offsets and carbon capture—both of which face skepticism over their environmental efficacy. Achieving these targets is undeniably daunting. Some airlines, such as Air New Zealand, have already abandoned their commitments, underscoring the scale of the challenge ahead. 

Obstacles in the way  

The reality is that many obstacles threaten airlines’ climate commitments, including:  

A slow start  

Laggards, in terms of climate action, airlines remain in the early stages of their green transition, behind the technological advances made elsewhere, such as in the car industry. 

A detrimental policy landscape 

Too many government policies still favor aviation over other forms of travel. Around the world, it remains heavily subsidized, creating artificially cheap fares and stopping consumers from making sustainable choices. Even in Europe – which claims it will become the first ‘climate-neutral continent’ – policies have created an unfair advantage for airlines. Recently, the European Commission caved to pressure from airlines to exclude long-haul flights from the scope of its aviation emissions monitoring scheme. 

Lack of scalable SAFs 

SAF technology needs a big breakthrough before it can go mainstream. The environmental alternatives to kerosene-based jet fuels are made from feedstocks, like waste oil and fats, green and municipal waste and non-food crops. The challenge is to make them available in the vast quantities required. Moreover, regulation is needed to stop carriers from unwittingly buying SAFs linked to tropical deforestation,  

Rise in greenwashing  

Too many airlines are trying to market themselves as sustainable prematurely. Earlier this year, a Dutch court ruled against KLM’s advertising claims that it offered ‘sustainable flying.’ This precedent-setting case provoked the eco-legal charity Client Earth to send legal letters to 71 airlines operating out of Schiphol Airport – including Ryanair, Delta, Lufthansa, and easyJet – warning them to respect the same greenwashing limits. A Wizz Air ad was recently banned in the UK for misleading green claims.  

Geopolitical havoc 

An increasing number of wars worldwide means airlines are forced to re-route flights, which hampers their attempts at cutting fuel usage and emissions. For example, Russia’s invasion of Ukraine has led to increased CO2 emissions on UK-Japan routes because Western carriers can't fly over Russian airspace and are forced to take longer routes.  

Increasing freight emissions 

Rising consumer demand for faster deliveries, coupled with a surge in online shopping and air cargo since the pandemic, has driven a 25% increase in greenhouse gas emissions from air freight operators compared with 2019. This unsustainable trend resulted in roughly 300,000 additional flights in 2023 compared with pre-pandemic levels, with the United States responsible for over 40% of global air freight emissions. 

The least sustainable way to travel 

Flying may appear to be a minor contributor to climate change—until one considers that it remains the privilege of a minority. Frequent flyers belong to an elite unlikely to bear the brunt of the climate crisis they help create.  

Aviation is the least sustainable mode of transport, producing the highest emissions per passenger kilometer. A single long-haul flight can generate as much carbon as some individuals in low-emission countries produce in an entire year.  

With aviation’s emissions forecast to rise by 14% this year compared with 2023 and the window for effective climate action narrowing, travelers should ask themselves if that flight is worth it.