How many air-miles are left in the world’s fuel tank?

Jet fuel

In BP’s Statistical Review 2005, jet fuel consumption figures are obscured by being “rolled-up” in regional statistics for “middle distillates”, which include kerosene, jet fuel, diesel and fuel oils. To obtain a rough guide for global jet fuel consumption, the US airlines consumed 18.5 billion gallons in 2004 compared with the US middle distillates consumption of 6087 thousand barrels per day in the same year. From this it can be derived that roughly 20% of the distillates production is civil aviation jet fuel.

Global oil products amounted to 77,028 thousand barrels per day in 2004 extracted from 80,260 barrels crude oil at an average refinery efficiency of 96%. Middle distillates totalled 27,741 thousand barrels per day and taking 20% of this and converting the result gives an aviation jet fuel consumption of 2.0 Gb (billion barrels) or 240 million tonnes.

Airbus predicted passenger traffic would consume 180 million tonnes in 2004, which with air freight traffic taking up the other 60 million tonnes or 25% of the total, a figure of 240 million tonnes or 2Gb, for passenger and cargo air transport, excluding military usage seems a reasonable estimation. 

Airport runways

In 2002 the UK Department of Transport announced a consultation on airport runway capacity, assuming that the usage of air transport will double by 2015 and triple by 2030. This is achieved by an exponential annual growth in passenger air traffic of 4.5% over the period. An expansion of air traffic in the UK would match a similar increase in international traffic. Domestic traffic in the UK and other countries would grow to feed rising international activity. The department concluded that airports should be expanded and runways built to match the anticipated demand.   

Passenger traffic

Airbus, the European aircraft manufacturer predicts an annual global growth rate in passenger traffic of 4.5% beginning in 2000 at 3.2 x 1012 passenger-km/annum (or 2 x 1012 air-miles/annum). If sustained this would rise to 12 x 1012 passenger-km/annum (or 7.5 x 1012 air-miles/annum) in 2030. The cumulative passenger-km over the 30 years totals 200 x 1012 passenger-km (or 125 x 1012 air-miles). 

Freight traffic

Airbus forecasts an increase in freight traffic of 5.9% per annum, rising from 120 x 109 tonne-km (75 x 109 tonne-miles) in 2005 to 440 x 109 tonne-km (270 x 109 tonne-miles) in 2023 to around 500 x 109 tonne-km (310 x 109 tonne-miles) by 2030, totalling 7,000 x 109 tonne-km (or 4,300 x 109 tonne-miles over the 26 years.

About a third of this freight is carried in the “belly” of passenger aircraft.

Civil aviation jet fuel requirement

With the introduction of the Airbus A380 super-jetliner and other fuel efficient aircraft from Boeing, it is expected that the jet fuel requirement for a fleet gradually renewed will reduce by 2% per annum, so that a 4.5% increase per annum in passenger traffic and a 5.9% increase in freight traffic would result in a 2.5% and 3.9% increase in jet fuel consumption per annum respectively.

This equates to a consumption in the 11 years up to and including 2015 of 2930 million tonnes or 24 Gb of jet fuel and in the 26 years up to and including 2030 of 9370 million tonnes or 76 Gb of jet fuel.  

Military uses

As well as military aircraft, jet fuel is now used for armoured vehicles, on the basis that battlefield logistics are aided by a uniformity of fuel for army helicopters and tanks. The use of jet fuel for military purposes depends on the level of war activity which has been exceptionally high over the last decade, but whether this is significant in depleting the oil resources it is intended to secure is a mute point.

Refinery yield

There is a reduction in the yield of jet fuel from 25% to 8-10% as North Sea crude oil production runs down and more Middle East crude has to be used. This means that the proportion of jet fuel to other refinery products is progressively reduced unless the refinery product profile is modified by installing additional equipment. More fuel is consumed internally, reducing the overall output while maintaining the yield of jet fuel, so a reduced refinery efficiency of say 91% will apply from now as a greater proportion of Middle East crude oil is refined. 

In 2004 global jet fuel consumption was around 2 Gb or 240 million tonnes which comprised 7.2% of total oil products. By 2015 crude oil production has fallen from a peak in 2010 of 30 Gb to 27 Gb, while the crude oil equivalent to the projected jet fuel requirement will be 2.65/0.91= 2.9 Gb (or 11% of oil production), but by 2030 oil production has fallen to 18 Gb, while the crude oil equivalent will have risen to 4.9/0.91= 5.4 Gb (or 30% of oil production). Demand for other oil products will make the attainment of 11%, let alone 30%, of crude oil production as jet fuel impossible.

Although the synthesis of jet fuel from natural gas or coal will offer some relief, there is no potential substitute for the bulk of the jet fuel currently obtained from crude oil. In any case the remaining natural gas and coal will be required for the myriad of competing energy-consuming purposes currently reliant on oil.

An exponential growth rate in passenger traffic of 4.5% and in freight traffic of 5.9% (in accordance with Airbus forecasts) would require an amount of jet fuel impossible to procure. 

Air miles

Accepting that peak oil occurs by 2007 and assuming that refinery profiles allow 7.2% of the declining crude oil production to be processed to jet fuel at 91% thermal efficiency, then from the 600 Gb of production of regular oil plus all other liquids available between now and 2030, around 40 Gb or 6400 billion litres of jet fuel would be produced. Assuming 25% of this is devoted to air freight, 30 Gb or 4800 billion litres would be available for global passenger traffic. An average specific consumption over the period of 3.8 litres per 100 passenger-km would provide 125 x 1012 air-km (or 78 x 1012 air-miles), compared with the 200 x 1012 passenger-km (or 125 x 1012 passenger-miles) or 60% of the traffic anticipated in the UK Department of Transport’s projections.

Freight miles

Consumption of the 10 Gb or 1,235 million tonnes of jet fuel available for freight traffic from 2005 to 2030 would allow for 3,160 x 109 tonne-km  of freight (2,000 x 109 tonne-miles) traffic compared with the 7,000 x 109 tonne-km (4,300 x 109 tonne-miles), i.e., 45% of that projected by Airbus.


In effect this means that over the 25 years leading up to 2030, only around 60% of the passenger and 45% of the freight markets’ expectations can be fulfilled, though the fuel deficit will be most evident towards the end of the period. Well before this aircraft orders will be cancelled and the enhanced fuel efficiencies anticipated will not be realised as the proportion of old aircraft will rise, exacerbating the fuel shortages.

The UK Department of Transport and Airbus forecasts do not consider the fuel resource implications inherent in their projected expansion in air traffic. This unconsidered factor determines that the growth in traffic envisaged cannot be realised as jet fuel production will be unable to match demand. The higher the rate of depletion of limited oil reserves, the sooner the collapse of the air travel business.

The building of additional runways in order to satisfy a perceived rise in passenger air travel, raises expectations that cannot be fulfilled. The runways at Stansted and Heathrow, if they are ever built, will serve as parking lots for redundant aircraft.

The demise of the aircraft industry will be signalled by the progressive grounding of the aircraft fleets, as a reduction in the supply of jet fuel will be the first indicator of the end of the oil era.

Global warming

Between 2005 and 2030 some 40 Gb (i.e. 5.04 billion tonnes) of jet fuel will be consumed. Taking account of the refinery loss of 91% gives an equivalent 5.54 billion tonnes of product with a carbon content of 85.8%. When burned it will yield 5.54 x 0.858 x 44/12 = 17.4 billion tonnes (or say 17 petagrams, i.e., 17 g x 1015) of carbon dioxide.

John Busby, 29 June 2005

Title page of The Busby Report