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Businesstravel Air Internationaleconomy emission factor trends — Global

International business travel by air in economy class (businesstravel_air_internationaleconomy) sits within a sector where emissions intensity per passenger-kilometre is shaped by aircraft efficiency, load factors, and route mix. The ICCT’s Aviation Vision 2050 (Sept 2025) projects that, under the Current Commitments scenario, the warming impact attributable to aviation per unit of travel is expected to fall from 0.118 mC in 2025 to 0.107 mC in 2050, signaling a decarbonization trajectory that increasingly decouples growth in international travel from emissions—provided technology progress and policy commitments continue (ICCT, 2025). This aligns with broader assessments that aviation remains a relatively small share of global CO2 but that substantial emissions reductions are achievable through sustained efficiency gains, sustainable aviation fuels (SAF), and policy measures (IEA, 2023; ICCT, 2025). Driving factors behind the projected trend include: (1) accelerated SAF deployment supported by regulatory mandates and incentives—such as the EU ReFuelEU Aviation framework and U.S. SAF incentives—which reduce the carbon intensity of jet fuel used in international operations (European Commission, 2023; IATA, 2024); (2) continued fleet renewal with next-generation, more fuel-efficient aircraft that lower fuel burn per passenger-kilometre (ICAO, 2023); and (3) improvements in air traffic management and route optimization (e.g., SESAR/NextGen initiatives) that shorten flight distances and reduce unnecessary holds, further trimming fuel use (Eurocontrol, 2023). Collectively, these dynamics support a downward trajectory in the economy-class international emission factor even as activity recovers, with policy-backed decarbonization pathways forecasting a gradual reduction in the sector’s warming impact through 2050 (ICCT, 2025; ICAO CORSIA).

Category
Business travel
Geography
Global
Unit
kgCO2e / km
Baseline
Baseline 2024 → 2050
Last updated
Updated

Regions covered: All regions

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Projection chart

Cumulative percentage change in the emission factor from the 2024 baseline. Shaded band shows min–max range; bold line is the Viable Pathway mid projection.

Data table (Viable mid projection)

Year Min Viable mid Max
2024 0.0% 0.0% 0.0%
2025 -0.1% -0.7% -1.4%
2026 -0.4% -1.8% -2.8%
2027 -0.7% -2.4% -4.1%
2028 -1.1% -3.0% -5.3%
2029 -1.5% -3.6% -6.5%
2030 -1.9% -4.2% -7.5%
2031 -2.2% -4.8% -8.6%
2032 -2.6% -5.3% -9.5%
2033 -3.0% -5.9% -10.4%
2034 -3.4% -6.4% -11.2%
2035 -3.7% -7.0% -12.0%
2036 -4.1% -7.5% -12.7%
2037 -4.5% -8.0% -13.4%
2038 -4.8% -8.5% -14.0%
2039 -5.2% -8.9% -14.5%
2040 -5.6% -9.4% -15.0%
2041 -6.0% -9.9% -15.4%
2042 -6.3% -10.3% -15.8%
2043 -6.7% -10.8% -16.2%
2044 -7.1% -11.2% -16.5%
2045 -7.5% -11.6% -16.7%
2046 -7.8% -12.0% -16.9%
2047 -8.2% -12.4% -17.0%
2048 -8.6% -12.8% -17.1%
2049 -8.9% -13.2% -17.2%
2050 -9.3% -13.6% -17.2%

How the Viable mid projection is calculated

Weighted projection based on pedigree quality assessments, normalised to 2024 emission factor

Sources and scenarios

Scenario Source Type Ambition Pedigree
DESNZ_Historic

Historic reductions from previous years projected linearly forwards.

UK Department for Energy Security and Net Zero

From 2016 to 2024, the emission flight factor has changed thus: 0.137124809 0.138014727 0.139964703 0.1384453 0.1392452 0.140625 0.140625 0.13464333 0.13465

historic base 2.2850736471922244
McKinsey_NaturalLimits

One scenario for the future is fuel efficiency gains reducing from 1.5% per year in 2024 down to 0% in 2050.

McKinsey & Company

According to a McKinsey analysis, carriers reduced their fuel consumption per passenger-kilometer by approximately 39 percent between 2005 and 2019 (pre-COVID-19), a compound annual growth rate of about 3.4 percent per year. The challenge moving forward is that the easy gains have already been captured, and airlines are starting to bump up against the natural limit of some of the improvement levers they used to achieve those gains. One scenario for the future is fuel efficiency gains tapering from 1.5% per year down. This is equivalent to the emission factor dropping from 2024 to 2050 like this: 0.13465 0.132707933 0.130870438 0.129133888 0.127494881 0.125950232 0.12449696 0.123132282 0.1218536 0.120658498 0.119544727 0.118510205 0.117553007 0.11667136 0.115863635 0.115128346 0.114464144 0.113869811 0.113344258 0.112886522 0.112495761 0.112171254 0.111912397 0.111718703 0.111589797 0.111525418 0.111525418

forecast modest 2.9635544148952118
ICCT_CurrentCommitments

The ICCT in Sept 2025 set out varying scenarios for the aviation industry. Under the Current Commitments scenario, from 2025 to 2050 the additional millidegrees Celsius (mC) of warming is projected to drop from 0.118 down to 0.107.

International Council on Clean Transportation

The ICCT in Sept 2025 (Aviation Vision 2050) set out varying scenarios for the aviation industry. Under the Current Commitments scenario, from 2025 to 2050 the additional millidegrees Celsius (mC) of warming is projected to drop from 0.118 down to 0.107.

forecast modest 2.090430209476521
ICCT_GHGForward

The ICCT in Sept 2025 set out varying scenarios for the aviation industry. Under the GHG Forward scenario, from 2025 to 2050 the additional millidegrees Celsius (mC) of warming is projected to drop from 0.118 down to 0.089.

International Council on Clean Transportation

The ICCT in Sept 2025 (Aviation Vision 2050) set out varying scenarios for the aviation industry. Under the GHG Forward scenario, from 2025 to 2050 the additional millidegrees Celsius (mC) of warming is projected to drop from 0.118 down to 0.089.

forecast ambitious 2.090430209476521
ICAO_NetZeroAspiration

The ICAO Net Zero Aspiration is a unrealistic scenario that states what emission factor trends are needed for global net zero by 2050.

International Civil Aviation Authority

The ICAO aspirational net zero 2050 goal is a commitment by its member states to achieve net-zero carbon emissions from international aviation by 2050. Adopted in October 2022, this goal supports the Paris Agreement's temperature objectives by emphasizing a collective responsibility for climate action within the aviation sector, though it remains non-binding and lacks specific obligations for individual states. This is equivalent of emission factors reducing from index 1 in 2022 to 0.1 in 2050.

forecast unrealistic 3.496960589918261
ViablePathway_WorstCase

This scenario assumes a 'fossil-fueled development' narrative with rapid growth in fossil fuel use, and no further reductions in flight emission factors.

Viable Pathway

This scenario assumes a 'fossil-fueled development' narrative with rapid growth in fossil fuel use, and no further reductions in flight emission factors.

forecast pessimistic 3.496960589918261

Changelog

  • — Updated vpmid mid from blended projection (len=27); appended source1 from UK Department for Energy Security and Net Zero (historic) year=2024, pedigree_score=2.2850736471922244.
  • — Updated vpmid mid from blended projection (len=27); appended source2 from McKinsey & Company (forecast) year=2022, pedigree_score=2.9635544148952118.
  • — Updated vpmid mid from blended projection (len=27); appended source3 from International Council on Clean Transportation (forecast) year=2025, pedigree_score=2.090430209476521.
  • — Updated vpmid mid from blended projection (len=27); appended source4 from International Council on Clean Transportation (forecast) year=2025, pedigree_score=2.090430209476521.
  • — No update of vpmid mid from unrealistic and unsubstantiated net zero ambition from source5 International Civil Aviation Authority (forecast) year=2022, pedigree_score=3.496960589918261.

Frequently asked questions

What is driving businesstravel air internationaleconomy decarbonisation in Global?

International business travel by air in economy class (businesstravel_air_internationaleconomy) sits within a sector where emissions intensity per passenger-kilometre is shaped by aircraft efficiency, load factors, and route mix. The ICCT’s Aviation Vision 2050 (Sept 2025) projects that, under the Current Commitments scenario, the warming impact attributable to aviation per unit of travel is expected to fall from 0.118 mC in 2025 to 0.107 mC in 2050, signaling a decarbonization trajectory that increasingly decouples growth in international travel from emissions—provided technology progress and policy commitments continue (ICCT, 2025). This aligns with broader assessments that aviation remains a relatively small share of global CO2 but that substantial emissions reductions are achievable through sustained efficiency gains, sustainable aviation fuels (SAF), and policy measures (IEA, 2023; ICCT, 2025). Driving factors behind the projected trend include: (1) accelerated SAF deployment supported by regulatory mandates and incentives—such as the EU ReFuelEU Aviation framework and U.S. SAF incentives—which reduce the carbon intensity of jet fuel used in international operations (European Commission, 2023; IATA, 2024); (2) continued fleet renewal with next-generation, more fuel-efficient aircraft that lower fuel burn per passenger-kilometre (ICAO, 2023); and (3) improvements in air traffic management and route optimization (e.g., SESAR/NextGen initiatives) that shorten flight distances and reduce unnecessary holds, further trimming fuel use (Eurocontrol, 2023). Collectively, these dynamics support a downward trajectory in the economy-class international emission factor even as activity recovers, with policy-backed decarbonization pathways forecasting a gradual reduction in the sector’s warming impact through 2050 (ICCT, 2025; ICAO CORSIA).

How does Viable Pathway calculate the mid projection?

Weighted projection based on pedigree quality assessments, normalised to 2024 emission factor

Discussion

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