The affluent part of humanity is mobile as it never was before, but there are signs that global travel’s big feast is coming to an end. [4 January 2011 | Peter Boyer]
An alien life form wanting to know about Earthly humanity could do a lot worse than watching the ebbs and flows of life in an airport terminal. These strange places are a pretty good analogy for modern life.
THE HIDDEN EXTRAS: Some lesser-known triggers than carbon dioxide are the main culprits for aviation’s very big short-term climate impact, according to a paper published in July 2010 by the American Chemical Society.
Airports are our age’s main transit centres: echoing, empty shells one moment, then suddenly buzzing with crowds of people. Unlike the crowds of the town square, the people don’t belong here. They’re from somewhere else, heading off to somewhere else again.
Humans have always been wanderers, but never in our history have we been as mobile as we are today. It took our remote ancestors thousands of years to travel the distances we can cover in a matter of hours.
Today there are about 18,000 commercial aircraft in service operated by 1300 airlines using about 1200 airports. Each year, more than 26 million passenger and freight flights take to the skies, involving five million million (five trillion if you like) passenger-kilometres and hundreds of millions of bums on seats.
Declaration: over the past five years I’ve flown about 75,000 km, which averages at 15,000 km a year. Based on an airline calculation that 0.1 kg of carbon dioxide is emitted per passenger kilometre for large airliners (a figure that needs to be qualified, as I’ll explain later), I’ve been personally responsible for 1.5 tonnes of air travel emissions for each of those five years.
Most people in the world never fly, so I’m not inclined to brag about my travel record. But it’s fairly modest in our affluent society, where increasing numbers of people are racking up hundreds of thousands of kilometres in a year and millions over a lifetime. If there’s one single marker of our fossil-fuel binge, this is it.
The travel industry would dispute this. The International Civil Aviation Organisation says that air transport accounts for no more than 2 per cent of global carbon emissions and is improving its record with “stringent engine emissions standards”, “effective operational measures” and “comprehensive environment policies”.
Such claims are repeated often by airlines, travel agents and tourism authorities everywhere, not to mention their clients whose lives revolve around travelling enormous distances quickly and often.
How could anyone oppose the idea of cheap, easy travel to the other side of the globe? We’re hard-wired to want to see what’s over the horizon, to sample other ways of life, other cultures and foods and beauty spots on and off the beaten track. If it’s a matter of cutting down on travel, we simply don’t want to know.
Or we take the option of paying extra for carbon pollution. Among the industry’s environment policies are various carbon offsetting schemes, available to Australian passengers mainly through airline websites, where they’re offered as an option after you’ve booked your flight.
The cost of offsetting varies enormously depending on the scheme on offer. If you choose a “gold standard” (a scheme arising out of collaboration between industry and conservation interests) you’ll pay an extra $12.30 for your return flight from Hobart to Melbourne, but some schemes charge a tiny fraction of that.
Offsetting schemes are supposed to reflect actual climate impact; such a large discrepancy shows that they can’t both be right. It’s very likely that neither of them is, according to a research study published a few months ago in the American Chemical Society’s journal Environmental Science and Technology.
An exhaustive study of the impact of the various forms of transport by Jens Borken-Kleefeld, an Austrian-based chemist, and Norwegian collaborators Terje Berntsen and Jan Fuglestvedt has found that while aviation’s long-term effect on greenhouse warming appears moderate, its short-term impact is much greater.
Taking the year 2000 as its baseline, the research team looked at the full range of emissions from different modes of transport (land, sea and air) and came up with some surprising conclusions.
Sea and rail transport, for instance, have a low near-term impact on warming because the particles in their “dirty” emissions have the effect of shielding Earth’s surface from sunlight. As these transport modes are “cleaned up”, their performance won’t look quite so good.
Airline engines are relatively clean, which is good — but not for their greenhouse bottom line. In fact, the ACS paper found that for five years after any given flight, the impact of an airliner per passenger-kilometre is four to five times that of the next worst offender, the car.
The study’s findings seriously undermine industry claims about climate impact — and throw into question the basis of every aviation offsetting scheme on the planet. Carbon dioxide emissions, on which most offsetting schemes are based, were found to be responsible for a mere 10.5 per cent of the aviation industry’s greenhouse impact. The real culprits — in the short-term having nearly nine times as much impact on warming temperature as carbon dioxide — are ozone pollution, condensation trails (“contrails”) and the cirrus clouds formed from contrails.
The industry may be right in claiming that aviation is responsible for only 2 per cent of global carbon emissions, but it’s conveniently overlooking the much greater near-term impact on the global temperature of non-carbon pollution — aviation’s unique contribution to global warming.
If you factor in the not-so-small matter of peak oil, which will play havoc with aviation fuel costs, it’s a pretty fair bet that jetliner travel as we know it has gone about as far as it can (or should) go. So when will the penny drop?