The growth in demand (i.e passenger numbers) has also resulted in a growth in carbon emissions, which increased by 130% between 1990 and 2007.

Emissions growth broadly reflects three main factors:

1. Growth in overall demand – this has grown by 130% over the same period.
2. Changes in composition of total flights as broken down by short haul and long haul.
3. Technology improvement

Emissions have grown more quickly than demand as a result of the relatively high growth of long-haul flights. These are relatively efficient in terms of emissions per passenger km, but account for a disproportionate share of emissions given much higher mileage on long-haul compared to short-haul. Long-haul flights therefore account for the majority of UK aviation emissions, despite the fact that short-haul flights account for higher passenger numbers.

Defra/ DECC Air passenger conversion factors

Source: Defra/DECC (2009)




UK Aviation CO₂   emissions: split by long and short-haul

Source: CCC analysis based on CAA data

 

Projections of emissions growth up to 2050

Emissions growth has been partially offset by technology improvement.  In analysing how emissions will grow up to 2050, the Committee has used demand projections and translated these into estimates of Air Traffic Movements (ATMs) – that is, the number of flights. These levels of ATMs have then been adjusted to provide emissions projections in line with what we anticipate can be achieved through improving aircraft design, engine efficiency, flight management and biofuels.

• With no runway capacity constraints and no carbon price, and if the carbon intensity of air travel remained unchanged (i.e. no technological progress) emissions would rise to just under 100 MtCO₂ in 2050.
• With planned capacity constraints and a central case carbon price, and with no technological progress, emissions are projected to rise to around 74 MtCO₂ in 2050