Carbon Footprint of Flying & Aviation
A single return long-haul flight can add 2–4 tonnes CO₂e to your annual footprint — more than many people emit from driving for an entire year.
CO₂ by route — economy class
Source: DEFRA/BEIS 2023 emission factors. Per passenger, one-way and return.
| Route | Distance | One-way CO₂ | Return CO₂ |
|---|---|---|---|
| London → Edinburgh | 640 km | 0.09t | 0.18t |
| London → Ibiza | 1,800 km | 0.18t | 0.35t |
| London → Lisbon | 1,800 km | 0.17t | 0.34t |
| London → New York | 5,600 km | 0.85t | 1.7t |
| London → Dubai | 5,500 km | 0.72t | 1.44t |
| London → Sydney | 16,900 km | 2.22t | 4.44t |
Why aviation has an outsized warming impact
Aviation's climate impact goes beyond CO₂. Aircraft flying at altitude also produce:
- Contrails — condensation trails that form ice clouds and trap heat. In some conditions these have more warming impact than the CO₂ itself.
- Nitrogen oxides (NOx) — which react in the upper atmosphere to form ozone (a greenhouse gas) and destroy methane (which would otherwise cause warming).
- Soot particles — which absorb solar radiation and warm the atmosphere.
The IPCC estimates that aviation's effective climate impact is 1.7–4× its CO₂ emissions alone. This page uses CO₂-only figures, so the real-world warming contribution is higher still.
Lower-carbon alternatives
For UK travellers, many popular routes have far lower-carbon alternatives:
- London → Paris: Eurostar emits ~6 kg CO₂ vs 58 kg for the equivalent flight — 90% less.
- London → Edinburgh: Train emits ~15 kg CO₂ vs 90 kg by air — 83% less.
- London → Amsterdam: Eurostar emits ~6 kg CO₂ vs 60 kg by air.
For longer journeys where flying is unavoidable, economy class direct routes produce the lowest per-passenger emissions. Choosing a direct route avoids the most emissions-intensive phases of flight (take-off and landing).
What you can do
- Replace short-haul European flights with train travel where feasible
- Choose economy over business or first class
- Fly direct where possible
- Offset unavoidable flights with high-quality, verified carbon credits
See how flights affect your total footprint
Our free calculator includes long-haul, short-haul, and domestic flights.
Calculate my footprint →Frequently asked questions
What percentage of global emissions comes from aviation?
Aviation accounts for approximately 2.5% of global CO₂ emissions, but its total warming impact is about twice that — around 3.5% of effective radiative forcing — because high-altitude contrails and nitrogen oxide emissions trap heat beyond CO₂ alone.
How much CO₂ does a flight produce?
A return economy flight from London to New York produces approximately 1.7 tonnes of CO₂ per passenger. Including non-CO₂ warming effects, the effective impact is closer to 3–4 tonnes CO₂e. A return London–Ibiza flight produces around 0.35 tonnes CO₂ per passenger.
Is business class worse for the environment than economy?
Yes — significantly. Business class seats take up 2–4 times more floor space than economy, so each passenger's emissions share is 2–4× higher. A business class return flight to New York can produce 5–7 tonnes CO₂e per passenger.
Does carbon offsetting make flying carbon neutral?
Carbon offsets can compensate for some emissions, but quality varies greatly. Many offsets represent future or uncertain carbon savings. The most reliable approach is to reduce flights where possible and use high-quality, verified offsets (Gold Standard or VCS) for unavoidable travel.