Monday, 10 October 2011

To fly or not to fly?

I have a very good friend who is a committed environmentalist. She goes on marches, doesn’t shop in supermarkets, has done a degree in environmental protection – and is intelligent and informed. I recently spoke to her and she mentioned that she would be out of contact for a while as she was going on holiday – to Dubai.

I know her well enough to ask the question which I don’t usually dare ask – which was – ‘how do you justify that, from an environmental point of view?’ To which she replied – ‘I don’t’. She added that she allows herself the quota of one flight a year, and that if everyone did that, then flying would not be the major issue in global warming which it is. Furthermore, she does not see that she needs to try to make up for other people’s contribution to global warming – it’s all about personal responsibility rather than one small group trying to save the world.

This is my attempt to work my way through the emotional issue that is air travel, and the contradiction that so many people have picked up before me, namely, that environmentalists seem for the most part to stop short at denying themselves the option of flying.

As a family, our personal dilemmas are these: first, we love love love to travel – a child of parents who both worked for airlines, I grew up using ‘planes as international buses; hop on, hop off. Secondly, we have made innumerable changes to our lives because of our views on climate change, but not to fly seems an enormous sacrifice. Thirdly, we have 2 kids who want to explore their world. What decisions should we make on their behalf? Fourthly, do we need to try to compensate for all the people who do fly by completely cutting it out of our lives? Fifthly, will we, if we end up rationing ourselves to, say one flight every 2 years, be considered as hypocrites, either by ourselves or others?

In the following paragraphs, I am looking at personal, rather than business travel. However, let me briefly say that whilst business travel has reduced somewhat in the UK, it still seems to be broadly justified by employees on the basis that it is part of the job and it is a reasonable request by the employer that cannot be refused; for businesses, that it is part of the wealth creation process and an economic reality. Indeed, this is a stumbling block for governments too – the argument is that aviation generates 8% of global GDP. These accepted excuses should be questioned, just as much as individual flying.

In the interests of openness, I should declare that whilst we haven’t travelled by ‘plane as a family for almost 3 years, Hugh makes occasional business trips. He has stopped flying outside Europe and takes trains to Paris and Brussels, but nevertheless, he feels obliged to fly in some cases. And in 2009 I jumped on a ‘plane faster than you can say environmental pollution when a friend of my father’s died unexpectedly abroad and I went, with my Dad, to the funeral.

I am going to look at the following issues:
1.The environmental impact of flying – we’re all told that flying is bad for the environment – but what’s the small print?
2.What are the options for reducing this impact?
3.What are the options for people who want to travel?

The environmental impact of flying
1.Air travel is not only just about the worst form of transport in terms of greenhouse emissions per passenger mile, it also enables people to travel so much further – so they emit a huge amount in a very short time. For instance – a round trip for 2 from London to San Fran emits the equivalent of about 5 tonnes of CO2. Or –10 months of domestic gas and electricity use for one home or driving 20,000 miles in an average car.

So even if, for argument’s sake, emissions per passenger mile in a 'plane were the same as in a car (which they’re not) – we tend to fly so much further than we would ever drive. The mean distance we drive in a year is 9,200 miles. We can easily fly that in a day.

2.Secondly - in 2009, civil aviation accounted for about 2% of global CO2 emissions, so do we really have to get into a stew about it? Well yes – because -

a)The vast majority of flights are taken by people in richer countries – so if you look at emissions per country, rather than the average, then you see that in some countries it contributes disproportionately to global emissions. For instance, in the UK in 2005, the figure was 6.3%. So already that 2% has grown into a somewhat more significant figure.

To put this into a somewhat more visual context, every single day more than 2.5m people fly through the airspace directly over metropolitan Paris - equivalent to about a quarter of its population. Can you imagine?

b)But even the figure of 6.3 could be severely underestimating the UK’s real impact. Since international flights take off from one country and land in another, 50% of emissions are allocated to the country where the ‘plane takes off and 50% where the ‘plane lands. So if I fly to Bangladesh, Morocco or Mozambique, only the equivalent of my outward journey, rather than my round trip, is included in the total of UK emissions. This skews the figures as UK residents take up 2/3rds of the seats on an average 'plane landing or taking off from a British airport; seats are not allocated equally; you never hear the Captain over the intercom apologising for a delay which is caused because we haven’t got 50% of seats taken up by Bangladeshis, Moroccans or Mozambicans...yet these countries are still hit with 50% of the emissions on their national totals.

c)Not included in these stats are emissions from the aviation industry from causes other than flying – for instance, manufacture and transportation of kerosene which is aviation fuel, manufacture and maintenance of 'planes, airport buildings and support vehicles .

The Rough Guide to Green Living estimates that aviation’s true impact in the UK amounts to between 13 and 15% of our total greenhouse gas emissions. And most flying is done by a small proportion of the total population.

d)More bad news – the height at which ‘planes fly increases the environmental impact of their emissions. They emit loads of bad things – but let’s just look at one aspect: emissions of soot and water vapour. The hot, wet water vapour, carrying soot in suspension, belches out of the aeroplanes and mixes, at high altitude, with the cold air in the atmosphere. This forms the vapour trails that you can see from the ground which are called ‘contrails’. Contrails then give rise to Cirrus clouds. These increase the impact of the greenhouse effect because they trap heat which would otherwise escape from the earth. During the day they also have the positive, counteractive effect of reflecting incoming sunlight, but at night their impact is all one way. Even during the day, the net effect is negative.

Whilst the science in this area is not totally solid, scientists in this field apply a multiplier of around two – ie the total environmental impact of a ‘plane ‘is approximately twice as high as its CO2 emissions’ . George Monbiot quotes the Intergovernmental Panel on Climate Change applying a multiplier of 2.7 .

e)Even more bad news: Aviation emissions have been growing faster than any other source of greenhouse gases. Between 1990 and 2004, the number of people using airports in the UK rose by 120%, and the energy the planes consumed increased by 79%. In the European Union, greenhouse gas emissions from aviation increased by 87% between 1990 and 2006. India has been spending more than $12bn on airport building. In 2006, its airlines had 330 new aircraft on order, to increase its fleet from 200 to 530. India's minister for aviation predicts that by 2020 up to 2,000 planes could be operating. China said in 2006 that it planned to buy 100 new planes every year over the next five years .

So this is an industry that is taking little notice of global warming, answering the demand of a growing proportion of the population which does not connect their flying with climate change. Or maybe people feel that they switch their lights off and recycle their cardboard and therefore they can fly to the Maldives on holiday with a clear conscience that they have done their ‘little bit’.

But before I give over to rant mode – let’s consider – are there options for reducing the impact of flying on the environment?

Technological possibilities
There have been advances in technology – the aeronautical industry claims that it has already made its fleet more efficient, by lowering weight, improving aerodynamics, fine-tuning engines and a range of other measures. But this doesn’t stop the trend of more and more people getting on planes and flying, so improvements in efficiency seem to me to be at best marginal.
Is it likely that a new engine will be developed and used which is massively more efficient, or uses a sustainable fuel? Well, as far as aircraft engines are concerned there don’t seems to be any new designs out there that make fundamental changes to the basic gas turbine that was designed in 1947. Secondly, and maybe more crucially, since planes bought today have a service life of up to 60 years, the current technology is embedded in the industry for a long time.

What about a different fuel?
Various have been considered but all are impractical. You can accept this statement and skip the next paragraph or if you’re really interested, read it.

The choice of low carbon fuels for aeroplanes is similar to the choice of low carbon fuels for cars. It is technically possible to fly planes whose normal fuel is mixed with about 5% biodiesel. Small difference, and anyway, biodiesel has already been shown not to be the answer to all our problems.
Ethanol is another fuel that has been suggested. However, it is a poor performer.Hydrogen is totally impractical. (According to George Monbiot, aircraft ‘could use hydrogen today, if instead of carrying passengers and freight they carried nothing but fuel – it contains four times less energy by volume than kerosene. But if this problem could be overcome, the researchers suggest, the total climate impacts of planes fuelled by the gas “would be much lower than from kerosene”. Unfortunately, when hydrogen burns, it creates water. A hydrogen plane will produce 2.6 times as much water vapour as a plane running on kerosene. This, they admit, would be a major problem if hydrogen planes flew as high as ordinary craft. But if the aircraft flew below 10,000 metres (33,000ft), where contrails are less likely to form, the impact would be negligible. However, because hydrogen requires a far bigger fuel tank than kerosene, the structure of the plane would need to be much larger. This means it would be subject to more drag.The only real alternative is “synthetic” kerosene made not from oil but natural gas, biogas or coal. It has the major advantage of working within current aircraft and therefore does not need new costly infrastructure. In fact, there are already ‘planes flying in South Africa fuelled on this technology – but made from coal and therefore not offering any significant emissions advantage over kerosene.


Is taxation a viable method to reduce demand and therefore emissions from aviation?
There are two possible targets to tax, passengers or the airline companies. Passengers already pay Air Passenger Duty, so if this is the chosen method to reduce demand, then this could be tweaked, controversial as it would be.
The easiest way to tax airlines, so that you could catch both national and international carriers, is to tax aviation fuel. Currently, there is no tax on aviation fuel. So tax on petrol, tax on wine, beer, cigarettes, income and death – but no tax on aviation fuel.That in itself is an interesting idea - why this exception? Why does this industry effectively have this subsidy?

Anyway, enough of the tangent. Could the UK take unilateral action on this front and introduce an aviation fuel tax? Well, it wouldn’t work too well, and would potentially damage the economy as airlines would try to fuel abroad and avoid the UK hubs.

The common feeling is that, for such a tax to succeed, it would have to be introduced worldwide, rather than piecemeal – in other words, by international treaty. An international treaty means international agreement which history has shown is hard to achieve. And we’ve all seen from Kyoto how toothless a treaty is without all key global players signing up.

However, there seems to be a chink of light at the end of the taxation tunnel...the global airline industry may be forced to join the EU's Emissions Trading Scheme (ETS) on 1 January 2012. This legislation imposes a carbon trading system that already includes most other polluting industries.

Connie Hedegaard, the Commissioner for Climate Action at the European Union (EU) says, "It seems high time that this polluter-pays principle is finally also applied to aviation's greenhouse gas emissions”.

However, and predictably, the highly competitive airline industry is in an uproar over the proposed tax policy with some media predicting a "global trade war" in the future.

Guess which states oppose this the most? The non-EU governments most opposed to the plan are the United States, China, India and Russia.

Carriers in the United States have taken the EU to the European Court of Justice for including airlines in the emissions trading scheme. The results of the case will be known on October 6 and will set a precedent for all other airlines.


As ever, there are personal, national and global solutions to this issue.

Global solutions are unlikely to happen. An international treaty is nowhere on the horizon, and few governments are prepared to priotritise global warming to the extent of taking unilateral action.

Nationally, there are more alternatives, although again, no government is going to want to put its economy in a less competitive position if that is the outcome of adopting such polices.

So, a government can legislate for a system that assigns every person a number of allowed air miles per year, and allow them to buy or sell these, (emission trading), or it can bring in a system of taxation.

So that leaves the somewhat uncomfortable personal.

As individuals, we can take the decision to stop flying. So many places in the UK and Europe are very beautiful and accessible by car or train. We can have fabulous holidays without going anywhere near a ‘plane.

Alternatively, we can personally ration the amount of flying we do – ie one flight a year, one flight every 3 years, whatever. We can also take action to set off our emissions.


This is a tough issue, and one where personal circumstances have a place, eg if family and close friends live abroad then obviously it is impractical to say that flying is a thing of the past. For me, I will probably go for the rationing option and fly once every 2 to three years. I am deeply uncomfortable with that, however, because even though it is not up to me and me alone to save the world, (and I can’t do it anyway without most other people engaging in this fight) there is no getting around the environmental damage that flying wreaks on the planet, and do I want to be a part of that?

The Rough Guide to Green Living
Leo Hickman – Is it ok to fly? Guardian, 20 May 2006
The Rough Guide to green Living
The Rough Guide to green Living
George Monbiot – On the Flight Path to global meltdown – Guardian, 21 September 2006
Leo Hickman – Is it ok to fly? Guardian, 20 May 2006
CNN GO 6 September 2011


  1. Found this link through @climatekevin (or @kevinclimate perhaps) on Twitter. Thanks for this, what a great piece.

    I haven't flown since 2008, when I realized the big picture on climate and emissions (not to mention Peak Oil). It was a tough decision, but I am adamant that I will not fly again unless it is using radically different technology than that found today.

    I'm also on Twitter, @jenniecph and also @aclimateworrier, and I've written 3 blogposts of my own on the flying dilemma, find them here if you're interested:

    It's just so vital that this gets talked and written about, it's hardly an issue, very worrying, as we're just 7 yrs away from reaching 2 degrees.

    All the best!

  2. Hi, Jennie - only just found this comment - thank you so much!I think that I already follwo you as @aclimateworrier. I will read your blogspot too.

    Best wishes,


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