Sky is the limit: The growing impact of air travel

by Terence Jeyaretnam

I recently heard about the resignation of a senor executive due to, what he felt, his company was doing as normal course of business.  His company is in tourism and as a consequence promoted air travel.  He felt his business was in the game of increasing air travel thereby increasing its greenhouse impact.  He was not comfortable with that value proposition, and indeed he is allowed to be choosy in a buoyant employment market.

Air travel is symbolised as a luxury and associated with holidays to faraway exotic destinations.  Air travel is also one of the fastest growing industries.  Around 85,000 flights take off every day, and this is set to double by 2050.  Aircraft are responsible for around three percent of global carbon dioxide emissions. But emissions of nitrous oxides (NOx) and the formation of condensation trails (contrails) from water vapour at near stratospheric levels where commercial jets fly mean the actual impact on global warming is much higher – possibly as much as ten percent.  Air travel is also on the rise, with GHG emissions from international air travel jumping by almost 70% between 1990 and 2002.  In China, air travel is growing by around 12% per year, and worldwide passenger air travel is increasing by 5% annually, a faster rate of growth than any other travel mode. Air freight has also been growing rapidly, though it remains a small share of total air traffic.

The net result, according to the Intergovernmental Panel on Climate Change, is that pollution from high-flying jets is up to four times as damaging to the environment as the same amount released by chimneys and exhaust pipes at ground level.  A single flight across the Atlantic can guzzle about 60,000 litres - more fuel than an average motorist uses in 50 years of driving.  Airliners are not covered by the Kyoto protocol, the international agreement to control emissions that contribute to climate change. However, in December European Union announced that from 2011 airlines flying in the EU will have to pay for the carbon they emit.  One of the modelling scenarios suggests that greenhouse gas emissions in the UK will be dominated by those related to air travel soon.  So, what are the solutions?

More efficient air crafts, a range of fuel sources, efficient traffic management, on-ground movement of planes and off-sets are just some of the many ways the industry is tackling this growing risk.  So what can the traveller do?  Some airlines are offering customers the chance to neutralise their emissions by purchasing carbon offsets: Virgin Blue recently introduced Virgin Green to allow online purchase of carbon credits with tickets.  I am predicting that Qantas will soon also offer a similar program.  But, before you can have your complimentary chardonnay and have a clear conscience ask yourself whether the next trip could have been avoided by a tele, video or skpe conference call or whether you could do more during the trip to avoid another one, or whether you could had another person from the local point attend on your behalf.

Source articles included Aviation and Climate Change by Globe-Net (June 2007) and Green Sky Thinking: Eight Ways to a Flying Future by The New Scientist (February 2007).

Terence Jeyaretnam is a Director of Net Balance (,
one of the world’s leading sustainability advisory firms.
Terence is based in Melbourne.