Flying: plane stupid? (Image: Image Source/Corbis)
You’ve insulated your house and turned down the thermostat. You’re eating less meat. You cycle to work. But a few times a year you fly.
In the UK, the average carbon footprint is around 10 tonnes a year, excluding flying – but a single round trip to New Zealand produces 12 tonnes of CO2. Is flying ever going to be anything other than the greatest of green sins?
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The short answer is no. There isn’t much scope for making planes more efficient, and nor have efforts to to fossil fuel-derived kerosene got very far. The ethanol-powered Embraer EMB 202 Ipanema does run entirely on biofuel, but it’s a single-seater used for crop dusting. Powering airliners with ethanol is problematic, not least because it freezes at normal cruising altitudes.
Flying cattle-class can help, because the more people crammed on a plane, the lower the per-person emission. But beyond this things get complicated. Planes burn fuel fastest during take-off, so you might think short-haul flights are worse. But the longer the flight, the more fuel is carried, and the more fuel is burnt to carry this fuel.
Claims that summer flights are better – because fewer heat-trapping contrails form then – are mired in uncertainty. Another suggestion is that flying during the day is better because contrails also reflect sunlight, compensating slightly for the heat they trap, but the difference may be negligible. As for taking less luggage, a jet can weigh 400,000 kilograms on take-off, only a tiny fraction of which is luggage.
So what about offsetting your emissions? The idea is that you pay a little extra to support projects such as installing solar panels or planting trees. But the quality of offset projects varies, says , an independent environmental consultant based in Zurich, Switzerland. Most companies selling offsets claim their projects are “verified”, but this is no guarantee of quality, Kollmuss says, nor that the projects in question wouldn’t have happened even without your contribution.
When it comes to planting trees, say, what matters is that the trees survive for decades to come. If they die or are cut down, the CO2 they locked away just ends up back in the atmosphere. “There are good offset projects out there,” says Kollmuss. “But it is very difficult for consumers to identity them.” Another option, she suggests, is that every time you fly you donate money to an organisation campaigning for action to prevent climate change.
Supporters of offsetting argue that it is at least better than doing nothing. But not even this is clear – opponents claim people who buy offsets may feel less guilty and fly even more as result. The bottom line is that if you can avoid flying, do.
Read more: “Guilty pleasures: Which bad habits can you get away with?“
This article appeared in print under the headline “Getting away with flying”
