Aviation’s carbon emissions are bigger and rising faster than the ‘2.5% of global emissions’ line suggests. In a flying nation like the UK, flying is on track to be the single largest-emitting sector by 2040, while only about 11% of the world’s people fly in any given year.
Flying on jet fuel creates carbon dioxide emissions, a greenhouse gas that warms the planet.
Every kilo of jet fuel burnt adds over three kilos of carbon dioxide to the atmosphere, and it takes an enormous amount of fuel to get a large aircraft off the ground and up to cruising altitude.
That cruising altitude, by the way, is a good way of visualising the top of our atmosphere. Looking up, it is easy to believe the ‘wild blue yonder’ is endless. In reality, it is a very limited space, and one that we are filling up with heat-trapping greenhouse gases.
It is becoming increasingly obvious that we need to stop putting large amounts of carbon into the atmosphere, and not only that, we also need to start taking some out again.
New rules are continually being put in place to require other industries to reduce their carbon emissions, but somehow aviation’s emissions (the blue ‘plume’ in the image below) are being allowed to grow unchecked.
Aviation emissions are skyrocketing
Aviation’s CO2 has roughly doubled since 1990 and reached about 940 million tonnes in 2024, up around 7% in a single year.
According to The Climate Action Tracker, if all sectors were to follow aviation’s carbon emissions lead, we would be living in a world that is, on average, over 4ºC hotter.
An often-used statistic about the climate impact of flying is that it only accounts for 2.5% of global CO2 emissions. This is normally followed by a statement about how we should focus our attention on other climate problems and leave the poor frequent flyers alone.
But the key word here is global, which spreads the responsibility across all humanity, when in fact only 11% of the global populationflies each year!
By 2040, flying could be the UK’s single biggest-emitting sector, neck and neck with agriculture.
If we dig a little deeper and look at flying emissions in countries that have active aviation markets, like the UK, then the numbers look very different. In 2025, flying will account for 8% of the UK’s total greenhouse gas emissions, and by 2040, a staggering 27%. By then, it will have become the highest-emitting sector, battling neck and neck with agriculture for that top position. But everyone has to eat, whereas aviation could be considered a luxury good. The vast majority of flights from the UK are currently for ‘leisure’ purposes.
When we stop looking at the figures from a countrywide perspective and instead focus on our individual behaviour, we see a similar pattern.
Flying is one of the most carbon-intensive activities many of us will ever do, and depending on how frequently we do it, it makes many of our other lifestyle choices seem almost insignificant.
And so far, we are only talking about the carbon; once we consider the contrails and other non-CO2 effects (link), the full warming impact is significantly higher.
What can you do?
Your choices carry real weight here because flying is such a big slice of a personal carbon footprint. The single most powerful thing you can do is fly less, especially the long-haul trips that dominate the total. When you do fly, go economy and direct, and pick the lowest-emission option. And talk about it: every conversation helps to raise awareness about the need to fly less.
Get Involved to push for the bigger changes that count.
Your questions:
How much of global emissions does flying cause?
Aviation is about 2.5% of global CO2, and closer to 4% of warming once non-CO2 effects are counted. But that small share understates it: it’s one of the fastest-growing sources, and a tiny minority of people cause most of it.
Is flying really that bad if it’s “only 2%”?
The average hides huge inequality. Roughly 1% of the world’s population causes about half of all aviation emissions, while around 80% of people have never flown, and a single long-haul flight can blow through more than a person’s entire sustainable annual carbon budget.
How much CO2 does one flight produce?
A long-haul return in economy is roughly 1 to 2 tonnes of CO2e per passenger, more than half of a sustainable yearly footprint (about 2 tonnes) in a single trip, and several times that in premium cabins.
Why do aviation’s emissions matter more than the percentage suggests?
Because the figure only counts CO2 (non-CO2 roughly doubles the warming), the industry is growing fast while others shrink, and the impact is concentrated among a small, wealthy group of frequent flyers.
