Air travel and 21st century fears

Air travel shows robust and sustained growth of 4 to 5% per year, and Airbus anticipates that air traffic will continue to grow at just under 5% annually.

The International Air Transport Association (IATA), the organization of the world’s airlines, expects to see a 31% increase in passenger numbers between 2012 and 2017, with total annual passenger numbers rising to just under 4 billion by the end of that period.

Such growth, it has been estimated, would require more than 29,000 new passenger and cargo aircraft with a value of more than US$ 4 trillion. Another estimate states that the number of aircraft in service in 2011 will double by 2031.

Two concerns – two fears – have the ability to derail this growth in the 21^st century, for different reasons and across different timescales. These concerns are the spread of Ebola virus (and future contagious diseases) and climate change.

Ebola virus

Ebola virus disease is an acute, often fatal illness in humans which first occurred in remote villages in Central Africa in 1976. It is transmitted to humans from wild animals, and in the human population through transmission from human to human. The average Ebola case fatality rate is about 50%; such rate has varied between 25 and 90% in previous outbreaks.

The present outbreak in West Africa ‘is the largest and most complex Ebola outbreak’ since Ebola was first discovered. As the World Health Organisation (WHO) notes,

[t]here have been more cases and deaths in this outbreak than all others combined. It has also spread between countries starting in Guinea then spreading across land borders to Sierra Leone and Liberia, by air (1 traveller only) to Nigeria, and by land (1 traveller) to Senegal.

Transmission during air travel

The incubation period of Ebola is from 2 to 21 days. People become infective with the onset of symptoms. The primary mode of transmission is from person to person through ‘direct contact with infected, symptomatic persons or their body fluids/secretions.’

WHO notes that infected persons have travelled internationally and that more Ebola cases ‘might be exported to non-affected countries.’ It also notes the possibility ‘that a person who has been exposed to the Ebola virus and developed symptoms may board a commercial flight,’ and that such persons ‘should seek immediate medical attention upon arrival, and then be isolated to prevent further transmission.’

Liability issues: More the contagion of fear of contagion …

WHO further states that risks to fellow travellers in a situation where a person who has been exposed to Ebola and then travels on a commercial flight are very low. It should also be noted that those who are contagious don’t have a chance to infect many other people before they are isolated during treatment. However, WHO does recommend ‘contact tracing’ in such circumstances.

Air travel by those exposed to Ebola virus raises the question of airline liability for passenger death or injury.

Liability for bodily injury or death of a passenger on board an international flight is determined by reference to international aviation treaties. The 1929 Warsaw Convention was the first of these treaties. The most recent is the 1999 Montreal Convention, and it is the treaty that will most likely apply to a passenger’s journey.

Article 17 of the Montreal Convention provides that a carrier:

… is liable for damage sustained in case of death or bodily injury of a passenger upon condition only that the accident which caused the death or injury took place on board the aircraft or in the course of any of the operations of embarking or disembarking.

Death or injury must be caused by an ‘accident.’ The most widely and generally accepted definition of an accident is set out in the decision in Air France v Saks, in which the US Supreme Court stated that liability under Article 17:

… arises only if a passenger’s injury [or death] is caused by an unexpected or unusual event or happening that is external to the passenger.

It would seem, then, that a health condition or a pre-existing injury that worsened as a result of air travel would not be an ‘accident’ for the purposes of the Montreal Convention. Moreover, as the UN aviation body, ICAO, and others have stated,

The risk of transmission of Ebola virus disease during air travel is low. Unlike infections such as influenza or tuberculosis, Ebola is not spread by breathing air (and the airborne particles it contains) from an infected person. Transmission requires direct contact with blood, secretions, organs or other body fluids of infected living or dead persons or animals, all unlikely exposures for the average traveller.

Nonetheless, it appears that Ebola fears have already affected the financial performance of the world’s carriers. Last week US airline shares fell by up to 6% ‘as part of an overall market slump’ due in part to fear of Ebola.

‘Mucking up the planet’

Another fear or concern which has the ability to derail aviation growth is climate change. It is considered that air travel is ‘the most carbon- intense form of travel.’

No matter what the aviation industry does to reduce emissions, it will be outweighed by growth in air travel, according to a new analysis. Growth will trump emissions cuts even if significant (and contentious) measures come into force to try and curb emissions – and those measures are decades away at best.

Last year, researchers calculated that total aviation emissions in 2006 were 630 million tonnes of carbon dioxide, and that by 2050, those emissions are projected to be between 1,000-3,100 million tonnes depending on how much air traffic grows, and how successfully we can tackle emissions with measures like improved fuel efficiency, biofuels, and emissions trading.

‘The last flight I ever take’

The new report referred to above by researchers at the University of Southampton shows there is not much the aviation industry can do to reduce emissions – and indeed it has not done much to date. ICAO lacks the legal authority to force airlines to cut emissions and, as the study’s authors point out, it relies on ‘voluntary cooperation and piecemeal agreements.’

If the status quo is maintained, civil aviation is forecast to become an increasingly significant contributor to global emissions.

As the meteorologist and journalist Eric Holthaus has said,