Dismiss my aerial engine, which on cloudless days
Has spirited me gently over land and sea.
Every so often, I receive an e-mail from a company called responsibletravel.com, advertising‘Holidays that give the world a break’.2 It arranges ‘real and authentic holidays that also benefit the environment and local people’.3 You can travel to the Quelqanqa Valley in Peru, where you can help build ‘three small footbridges across the two rivers that run close to the village’.4 You can take ‘a one-week safari with a difference!’ in Kenya, where the fees you pay to enter the Samburu National Park and the Maasai Mara reserve fund ‘amenities such as schools and medical facilities for the local people’.5 You can visit Hokkaido in Japan, where your holiday will help to restore ‘original wetland’.6 Its website quotes the Cree Indian saying reproduced endlessly on t-shirts and posters: ‘Only when the last tree has died and the last river been poisoned and the last fish been caught will we realize that we cannot eat money.’7
Even if we forget that Andean villagers are likely to be rather better at building bridges than IT consultants from north London, that the gate fees from Kenyan game reserves tend to be spent on anything except amenities for local people,8 that it would be hard to characterize the Japanese as being in need of foreign aid and that – to judge by its tariffs – responsibletravel.com is just as good at eating money as any other travel firm, something is missing from its account. The tourists have to get there. And unless the holiday incorporates a bike ride to the Maasai Mara or a rowing trip to Hokkaido, they are going to get there by air.
You could build 3,000 footbridges, spend your life’s savings on gate fees in Kenya, slosh around in wetlands until you had trench foot, and not redress a fraction of the impact caused by your flight. In the name of assisting the people of developing countries, this company is helping to starve the Ethiopians and drown the people of Bangladesh.
I have picked on responsibletravel.com not because it is exceptional in its disregard for the impact of air travel, but because it is typical. We have all mastered the art of beginning and ending a narrative at the points which suit us, and we are never more adept at this than when we travel. A holiday – and therefore its environmental impact – we choose to believe, begins upon arrival and ends upon departure. The getting there and back has nothing to do with it.
Even those who recognize that we don’t arrive by means of teleportation seek to underplay the impacts of aviation. In an article in the Independent extolling the virtues of ‘ethical tourism’, Anita Roddick, founder of the Body Shop and funder of a thousand good causes, acknowledges that
Some people are suspicious of the whole idea of ethical tourism, arguing that, to reach most places, you have to travel by air – which is itself unethical. It is true that the government expects air travel passengers to double by 2030, by which time air travel will be the biggest contributor to global warming. However, it is also true that the airline industry can now create fuel-efficient planes. The Sustainable Aviation Group, which includes BA and Virgin, aims to introduce new aircraft producing 50 per cent less carbon dioxide than 2000 models.9
This, as we shall see, is unlikely to happen: the airline companies’ projections resemble those of the motor industry, in that they appear to be designed principally for the purpose of public relations. Even if this improvement did take place, it would not counteract the rising emissions caused by the growth in flights, as Roddick herself shows. She is also sufficiently well informed to know that the other measures she proposes – emissions trading and tree planting – are not, under current circumstances, going to work, as I will explain in a moment and in Chapter 11. But her determination to suggest that long-distance tourism is sustainable as long as we distribute money and goodwill when we arrive supports my contention that well-meaning people are as capable of destroying the biosphere as the executives of Exxon.
Our moral dissonance about flying reminds me of something a Buddhist once told me when I questioned his purchase of unethical products. ‘It doesn’t matter what you do, as longas you do it with love.’ I am sure he knew as well as I did that our state of mind makes no difference either to the exploitation of workers or to the composition of the atmosphere. Thinking like ethical people, dressing like ethical people, decorating our homes like ethical people makes not a damn of difference unless we also behave like ethical people. When it comes to flying, there seems to be no connection between intention and action.
This is partly, I think, because the people who are most concerned about the inhabitants of other countries are often those who have travelled widely. Much of the global justice movement consists of people – like me – whose politics were forged by their experiences abroad. While it is easy for us to pour scorn on the drivers of sports utility vehicles, whose politics generally differ from ours, it is rather harder to contemplate a world in which our own freedoms are curtailed, especially the freedoms which shaped us.
I have heard people argue that less travelling from the rich nations to the poor nations could result in a narrowing of the public mind. This might be true. But it is also clear – as the public response to the Asian tsunami and the recent enthusiasm for tackling poverty in Africa suggests – that our compassion for other people can be stimulated just as well by effective use of the media.
More painfully, in some cases our freedoms have become obligations. When you form relationships with people from other nations, you accumulate love miles: the distance between your home and that of the people you love or the people they love. If your sister-in-law is getting married in Buenos Aires, it is both immoral to travel there – because of climate change – and immoral not to, because of the offence it causes. In that decision we find two valid moral codes in irreconcilable antagonism. Who could be surprised to discover that ‘ethical’ people are in denial about the impacts of flying?
There are two reasons why flying dwarfs any other impact a single person can exert. The first is the distance it permits us to cover. According to the Royal Commission on Environmental Pollution, the carbon emissions per passenger mile ‘for a fully loaded cruising airliner are comparable to a passenger car carrying three or four people’.10
In other words, they are about half those, per person, of a car containing the average loading of 1.56 people. But while the mean distance travelled by car in the United Kingdom is 9,200 miles per year,11 in a plane we can beat that in one day. On a return flight from London to New York, every passenger produces roughly 1.2 tonnes of carbon dioxide:* the very quantity we will each be entitled to emit in a year once a 90 per cent cut in emissions has been made.†
The second reason is that the climate impact of aeroplanes is not confined to the carbon they produce. They release several different kinds of gases and particles. Some of them cool the planet, others warm it. The overall impact, according to the Intergovernmental Panel on Climate Change, is a warming effect 2.7 times that of the carbon dioxide alone.13 This is mostly the result of the mixing of hot wet air from the jet engine exhaust with the cold air in the upper troposphere, where most large planes fly. As the moisture condenses it can form condensation trails which in turn appear to give rise to cirrus clouds – those high wispy formations of ice crystals sometimes known as ‘horsetails’. While they reflect some of the sun’s heat back into the space, they also trap heat in the atmosphere, especially at night. The heat trapping seems to be the stronger effect.14 This means that subsonic aircraft, if all their seats are full, cause roughly the same total warming per passenger mile as cars. While the different warming effects are not directly comparable, because carbon dioxide stays in the atmosphere for much longer than condensation trails or cirrus clouds, if we were to multiply the carbon emissions produced on that round-trip to New York by 2.7, we would, of course, exceed our annual allowance on that journey by the same factor.
Supersonic aircraft, such as Concorde (which is now retired) and some military planes, are far more damaging. They fly not in the upper troposphere (where planes cruise at between 10 and 13 kilometres), but in the stratosphere, at between 17 and 20 kilometres above the surface of the earth. The water vapour they produce there ensures that their total impact is around 5.4 times that of the carbon dioxide alone. Discussing the small supersonic ‘business jets’ whose development is allegedly being pursued by NASA, General Electric and Lockheed Martin,15 the Royal Commission abandons its customary restraint.
The contribution to global climate change of this kind of aircraft would be so disproportionate that their development and promotion must be regarded as grossly irresponsible.16
Aviation has been growing faster than any other source of greenhouse gases. Between 1990 and 2004, the number of people using airports in the United Kingdom rose by 120 per cent, and the energy the planes consumed increased by 79 per cent.17 Their carbon dioxide emissions almost doubled in that period – from 20.1 to 39.5 million tonnes,18 or 5.5 per cent of all the emissions this country produces.19
Unless something is done to stop this growth, aviation will overwhelm all the cuts we manage to make elsewhere. The government predicts that, ‘if sufficient capacity were provided’, the number of passengers passing through airports in the United Kingdom will rise from roughly 200 million today to ‘between 400 million and 600 million’ in 2030.20 It intends to ensure that this prophecy comes to pass. The new runways it is planning‘would permit around 470 million passengers by 2030’.21
You might wonder how the British government reconciles this projection with its commitment to cut carbon emissions by 60 per cent by 2050. The answer is that it doesn’t have to. As the Department for Transport cheerfully admits,
International flights from the UK do not currently count in the national inventories of greenhouse gas emissions as there is no international agreement yet on ways of allocating such emissions.22
This is a remarkable evasion. It is true that there is ‘no international agreement yet’. But a child could see that you simply divide the emissions by half. The country from which passengers depart or in which they arrive accepts 50 per cent of the responsibility. Are we really to believe that the civil servants in the Department for Transport can’t work this out? As 97 per cent of the greenhouse gases they expect planes to be producing by 2030 will come from international flights,23 this profession of incompetence is, to say the least, convenient. You need do nothing about the carbon emissions from aeroplanes as officially they don’t exist.
By way of remedy, the transport department suggests that the aviation industry should ‘pay the external costs its activities impose on society at large’.24
This is an interesting proposal, but unfortunately the department does not explain how it could be arranged. Should a steward be sacrificed every time someone in Ethiopia dies of hunger? As Bangladesh goes under water, will the government demand the drowning of a commensurate number of airline executives? The idea is strangely attractive. But the only suggestion it makes is that aviation fuel might be taxed:
a notional 100 per cent fuel tax would lead to… a 10 per cent increase in air fares, assuming the increased costs were passed through in full to passengers. This would then have the effect of reducing demand by 10 per cent.25
A few pages later, it admits that this mechanism is in fact useless, because the airlines will keep cutting the remainder of their costs.26 The government is also aware that aviation fuel taxes on international flights are more or less impossible to impose. They are prohibited under international law by Article 24 of the 1944 Chicago Convention, which has been set in stone by around 4,000 bilateral treaties.27 We environmentalists have been stupid enough to do what the industry wants, and loudly demand the taxes it has no cause to fear.28
So the government relies instead on incorporating aviation into the European Emissions Trading Scheme. This, it hopes, will happen in 2008. In principle – though with the major caveats I mentioned in Chapter 3 – the idea is sound: an overall carbon limit is set for the participating industries, and the market is left to allocate emissions between them. The problem is that if government policy is still driving the growth of the airlines, and low prices continue to stimulate demand, either the emissions from every other industry within the scheme must contract at a much greater rate than before to accommodate aviation’s expansion, or it will break the system. The second option appears to be the more likely. Incorporating the industry into the trading scheme without other policies to reduce its growth merely defers the decision the government needs to take, while threatening the remainder of its climate-change programme.
The one certain means of preventing the growth in flights is the one thing the British government refuses to do: limit the capacity of our airports. It employs the ‘predict and provide’ approach which has proved so disastrous when applied to road transport:* as you increase the provision of space in order to meet the projected demand, the demand rises to fill it, ensuring that you need to create more space in order to accommodate your new projections. The demand would not have risen in the first place if you hadn’t created the space. The House of Commons Environmental Audit Committee calculates that the extra capacity the government proposes means ‘the equivalent of another Heathrow every 5 years’.30 Twelve regional airports in the UK have recently announced expansion plans.31 Ministers are now beginning to promote new runways at Heathrow, Stansted, Birming ham, Edinburgh and Glasgow.
In 2005, Friends of the Earth asked the Tyndall Centre to determine what impact this growth would have on greenhouse gas emissions.32 The results were staggering. If we attempt to stabilize carbon dioxide concentrations in the atmosphere at 550 parts per million (which roughly corresponds to the government’s target), and aviation continues to grow as the government envisages, by 2050 it would account for 50 per cent of our carbon emissions. If we tried to stabilize them at 450 parts (which is closer to my target) flying would produce 101 per cent of the carbon the entire economy was able to release. If the carbon emissions were multiplied by 2.7, to take into account the full impact of aviation on the climate, the figures would be 134 per cent and 272 per cent respectively.*34 The researchers assumed that the fuel efficiency of aircraft will improve by 1.2 per cent a year throughout this period. This could be optimistic.35
While the British government appears determined to turn this country into the nation Orwell envisaged in 1984 – Airstrip One – aviation is booming everywhere. Worldwide, it has been growing by about 5 per cent a year since 1997.36 The Intergovernmental Panel on Climate Change suggested it would account for between 3 and 10 per cent of global carbon emissions by 205037 (and that this impact could be amplified 2.7 times). But the Royal Commission reports that growth has so far been higher than it envisaged: the panel’s prediction ‘is more likely to be an under-estimate rather than over-estimate’.38
Faced with both their lobbying power and the aspirations of their customers, hardly any government appears to be brave enough to stand up to the airlines. The British Department for Transport, like the airline industry, claims that expanding airport capacity is ‘socially inclusive’, in that it enables poorer people to fly.39 But as the Environmental Audit Committee points out, it seems to have conducted no research on this subject.40 An organization which has – the Civil Aviation Authority – found that people in social classes D and E (at the bottom of the official economic scale) scarcely fly at all. Though flights are often very cheap, they can’t afford to take foreign holidays: even in the age of the 50p ticket, people in these classes buy just 6 per cent of the tickets.41 A MORI poll commissioned by the Freedom to Fly Coalition (which is a lobby group founded by the aviation industry) found that 75 per cent of those who use budget airlines are in social classes A, B and C.42 Another survey shows that people with second homes abroad take an average of six return flights a year.43 But even if everyone in the rich nations were able to fly every year, the impact of aviation would still be regressive, as the people who are most vulnerable to climate change are the poorest inhabitants of the poorest nations, the great majority of whom will never board an aeroplane.
There are two means by which the growth in flights could be reconciled to the need to cut carbon emissions. The first is a massive increase in the fuel efficiency of aircraft; the other is a new fuel.
The British government’s White Paper on aviation claims that
Research targets agreed by the Advisory Council for Aeronautical Research in Europe suggest that a 50 per cent reduction in carbon dioxide production by 2020 can be achieved.44
This statement, as the House of Commons Environmental Audit Committee has pointed out, is deliberately misleading.45 What the Advisory Council actually said is that its target, which is purely aspirational, cannot be met by improving the existing kinds of aircraft engine. It requires ‘breakthrough technologies’ which don’t yet exist.46 When you consider the design life of modern aircraft, you discover that the council’s ‘research target’ bears even less relation to actual performance. Planes are remarkably long-lived. The 747 – the Jumbo jet – was launched in 1970 and is still flying today. The Tyndall Centre predicts that the new Airbus A380 will still be in the air, though ‘in gradually modified form’, in 2070,47 and it will continue to use ‘high-pressure, high-bypass jet turbine engines that contain only incremental improvements over their predecessors’.48
A 50 per cent cut by 2020 means not only discovering a new technology and designing, testing, licensing and manufacturing the planes that use it, but also scrapping and replacing the entire existing fleet, and the tens of billions of pounds the aviation companies have invested in it.
As far as aircraft engines are concerned, ‘breakthrough technologies’ appear to be a long way off. The Royal Commission reports that
The basic gas turbine design emerged in 1947. It has been the dominant form of aircraft engine for some 50 years and there is no serious suggestion that this will change in the foreseeable future.49
It is hard to see how major new efficiencies could be squeezed out of it. The proposals the aviation industry has put forward, the Royal Commission says, might improve fuel efficiency somewhat, but only at the cost of an increase in noise and local pollution caused by nitrogen oxides.50 I don’t believe that those who live under the flight paths (an increasing proportion of the population as aviation expands) will put up with this.
Worse still, as a report for the European Commission by the aviation scientist Ulrich Schumann notes,
Recent experiments have provided evidence that contrails form at lower altitude and hence more frequently when using more efficient engines.51
‘Contrails’ are the condensation trails largely responsible for boosting the impact of aviation on the climate, as discussed above. In other words, jet engines might be able to burn less fuel, but the warming they cause could remain constant or even increase.
The only technology which does offer a major improvement in fuel efficiency, creates fewer condensation trails (because it is used at lower altitudes) and is known to work is one plucked not from the future but the past: the propeller plane. According to the industry coalition Avions de Transport Régional, the most efficient commercial propellor planes use just 59 per cent as much fuel per passenger mile as a jet aircraft.*52 But as the ‘Régional’ part of their name suggests, they advocate its use only for short-haul flights. Short-haul flights are inherently inefficient, because of the higher proportion of the journey spent taking off and gaining height. They are also, on the whole, unnecessary, as there are other means of covering that distance: it would be better for the environment to travel by coach or by train. The table below gives the figures I provided in Chapter 8, with the carbon emissions from short-haul flights added.
No one in the industry appears to be giving serious consideration to the idea of returning to long-haul propellor planes, because they are much slower than jets. The most promising approach to redesigning the rest of the aircraft is a concept called the ‘blended wing-body’. Planes of this kind would have huge hollow wings in which some of the passengers would sit. By cutting drag, they could reduce the amount of fuel a plane uses by up to 30 per cent.53 But, as the Royal
mode of transport from London to Manchester |
carbon dioxide emissions per passenger (kg) |
planei (70 per cent full) |
63.9 |
car (1.56 passengers) |
36.6 |
train (70 per cent full) |
5.2 |
coach (40 passengers) |
4.3 |
i. The Department for Transport estimates that short-haul flights use 150g of carbon dioxide per passenger kilometre54 Manchester is 298km from London. This gives 44.7kg/passenger for a fully laden plane.
Commission points out, it’s still just a concept, and ‘the stability and controllability of such an aircraft are unproven.’55
There is some scope for reducing the amount of fuel that planes burn by improving air traffic control (so that they spend less time in the stack) and allowing them to take more direct routes. But this amounts to just 10 per cent or so.56 If aircraft flew at lower altitudes, they would produce fewer condensation trails and cirrus clouds, but because the air is denser there – so the planes would be subject to more drag– they would burn more fuel.57 The net effect might be beneficial, but this remains uncertain.58
The choice of alternative fuels for aeroplanes is similar to the choice of alternative fuels for cars. According to a paper by researchers at Imperial College, London, it is technically possible to fly planes whose normal fuel (kerosene) is mixed with small amounts of biodiesel.59 At low temperatures, oils go cloudy, and at a couple of degrees lower still they form a gel. This can block an engine’s fuel filters, fuel lines and plugs. Biodiesel’s ‘cloud point’ is much higher than kerosene’s. Even a mixture containing as little as 10 per cent biodiesel can raise the cloud point from –51° to –29°. This, because of the low temperatures in the upper troposphere, could stop the engines if the plane flew at normal heights. But if the fuel is repeatedly chilled and the crystals which form filtered out, a 10 per cent mixture raises the cloud point by only 4° (they don’t say how much energy this chilling would use).60 This would permit the plane to fly at up to 9,500 metres. Of course the biodiesel used in planes is subject to the same environmental constraints as the biodiesel used in cars: it is likely to cause more global warming than it prevents.
Ethanol, the same paper suggests, would be useless: it is insufficiently dense and, in aeroplanes, extremely dangerous. Kerosene could be made from wood, but (aside from the enormous expense), its production will be limited by the land-use issues I discussed in Chapter 6: the trees we are able to grow would be better employed discharging the more necessary function of keeping us warm. You will have guessed by now that this leaves only our familiar fall-back, hydrogen.
In this case, it would be burnt not in fuel cells, but in combustion engines similar to those used in planes today. Carrying liquid hydrogen seems to be a more viable option for planes than for cars, but the energy costs (about 35 per cent) of keeping the temperature below –259° remain unchanged. Several planes have already been flown with one engine running on hydrogen. In principle, jets could use this fuel today, if instead of carrying passengers and freight they carried only hydrogen. Though it is lighter, it contains four times less energy by volume than kerosene. But if this problem could be overcome, the researchers at Imperial College suggest, the total climate impacts of planes fuelled by the gas ‘would be much lower than from kerosene’.61 Unfortunately, they appear to have forgotten something.
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, they suggest, the aircraft flew below 10,000 metres, where condensation trails are less likely to form, the impact would be negligible. What they have forgotten is that because hydrogen requires a far bigger fuel tank than kerosene, the structure (or ‘airframe’) of the plane would need to be much larger. This means it would be subject to more drag. The Royal Commission on Environmental Pollution – which as usual appears to have thought of everything – points out that ‘the combination of larger drag and lower weight would require flight at higher altitudes’ than planes fuelled by kerosene.62 In fact, hydrogen planes, if they are ever used, are most likely to be deployed as supersonic jets in the stratosphere. This would be an environmental disaster.
a hydrogen-fuelled supersonic aircraft flying at stratospheric levels would be expected to have a radiative forcing [which means a climate-changing effect] some 13 times larger than for a standard kerosene-fuelled subsonic aircraft.63
And that, I am afraid, is it. As the Intergovernmental Panel on Climate Change discovered,
there would not appear to be any practical alternatives to kerosene-based fuels for commercial jet aircraft for the next several decades.64
Even the British government, which at other times manages to find its way to the conclusions the aviation industry requires, admits that ‘there is no viable alternative currently visible to kerosene as an aviation fuel.’65
There is, in other words, no technofix. The growth in aviation and the need to address climate change cannot be reconciled. Given that the likely possible efficiencies are small and tend to counteract each other or to be unacceptable for other reasons, a 90 per cent cut in emissions requires not only that growth stops, but that most of the planes which are flying today are grounded. I recognize that this will not be a popular message. But it is hard to see how a different conclusion could be extracted from the available evidence.
The obvious next question, then, is this. Are there other means of covering the same distances at the speeds with which we are now familiar?
Commercial airliners such as the Boeing 747 or the Airbus A321 have cruising speeds of around 900 kilometres per hour. The fastest form of mass transit across the surface of the earth is the ultra-high speed train. The French TGV – Train à Grande Vitesse – holds the record for a wheeled train, of 515 kmph.66 Locomotives that are suspended above the track by magnetic repulsion – maglevs or magnetic levitation trains – can beat this. In 2003, a test train in Japan managed 581 kmph.67 But the fastest working train in the world is the TGV from Lyons to Aix-en-Provence. It covers 290 kilometres in 66 minutes, an average speed of 263 kmph.68 Trains are not – or not yet – as fast as planes, but when the check-in, boarding and waiting times and the travel to and from the airports are taken into account, they can cover journeys of a few hundred kilometres in roughly the same time. Given that they are generally more convenient and relaxing than planes, it might be possible to persuade people of the advantages of using ultra-high-speed trains for journeys of up to about 2000 kilometres, even though these would take longer. Beyond that point, the journey, for people accustomed to moving at Faust’s speed, would start to drag: 8,000 kilometres – from London to Beijing for example – takes 31 hours at 260 kmph. The companies and governments proposing new ultra-fast lines hope to draw people away from planes by raising average speeds to 350 or even 500 kmph.69,70,71
The first obstacle you discover is the cost. The 30-kilometre maglev system between Shanghai and its airport cost $1.2 billion.72 The link between Edinburgh and Glasgow, on which the bullet train some politicians have been proposing would run, would probably cost over £4 billion, or around $7 billion, for 71 kilometres of track.73 The cost of the 500-kilometre maglev line which might one day cut through the mountains between Tokyo and Osaka has been estimated at $82.5 billion.74 These prices suggest costs of $40 million to $165 million per kilometre. The French have been able to build TGV lines for much less, however. The Méditerranée link cost about €23 million ($28 million) per kilometre, and the Atlantique €10 million ($12 million).75 An 8,000-kilometre track, if the price could be kept as low as the Atlantique’s, would cost $96 billion to lay.
It would also take a long time. Public inquiries should be held in the countries through which the line might travel. Rights of passage must be negotiated and the land bought, then a massive engineering project undertaken. With a sufficient sense of urgency the construction of a series of trans-continental TGV lines could be completed within the timeframe considered by this book. But should it be done?
You will not be surprised to see me report that there is a problem. Though trains travelling at normal speeds have much lower carbon emissions than aeroplanes, a discussion paper by Professor Roger Kemp of Lancaster University shows that energy consumption rises dramatically at speeds over 200 kmph.76 Increasing the speed from 225 kmph to 350 kmph, he reveals, almost doubles the amount of fuel they burn. If the trains are powered by electricity, and if that electricity is produced by plants burning fossil fuels, then a journey from London to Edinburgh by a train travelling at 350 kmph, Kemp’s figures suggest, would consume the equivalent of 22 litres of fuel for every seat. An Airbus A321 making the same journey uses 20 litres per seat.77
Trains, of course, don’t produce condensation trails, so the total global warming effect is smaller. But we are still seeking a 90 per cent carbon cut. The 350 kmph link between London and Scotland that Tony Blair appeared to endorse in 200478 would, by comparison to flying, deliver a 10 per cent carbon rise. Even if speeds were confined to 250 kmph, Kemp’s graph suggests, trains would still consume 14 litres of fuel per seat, giving us a carbon cut of just 30 per cent.79 In reality, the effects of ultra-high-speed trains would be worse than this, for they would draw people not only out of planes, but also out of slower trains and coaches.
Ultra-high-speed trains, in other words, can be part of the solution only if they run on electricity and it is provided by renewable power and fossil fuel combustion with carbon capture and storage. As they are likely to use only a small percentage of a nation’s total power, this should be possible, within the limits set by this book. Trains of this speed powered by engines using their own fuel must be ruled out altogether. But if we are to keep using the railways for passenger transport, the cheaper and more environmentally responsible approach is to keep the average speed of our trains to below the current maximum (in the United Kingdom) of roughly 180 kmph. High performance and low consumption are, again, at odds.
The fastest ocean-going passenger ships cruise at about 30 knots, or 54 kmph. They could go faster. A company called BGT Industrial claims to have made the engines for a freighter which can travel at 70 knots (130 kmph).80 Even if passenger ships could travel this fast, however, it is still just one seventh of the speed of an airliner. And it is not clear that ships offer carbon savings anyway.
It is remarkably hard to obtain comparative figures for fuel consumption, but George Marshall of the Climate Outreach Information Network has conducted a rough initial calculation for the Queen Elizabeth II, the luxury liner run by Cunard, which cruises at between 25 and 28 knots (45–50 kmph). It has to be said that the QEII does not exactly optimize its space. It contains seven restaurants and seven lounges, a branch of Harrods and dozens of other shops, cabins big enough for dinner parties, and 920 crew members to serve just 1,790 passengers.81 But even taking all this into account, the figures don’t look good. Cunard says the ship burns 433 tonnes of fuel a day, and takes six days to travel from Southampton to New York. If the ship is full, every passenger with a return ticket consumes 2.9 tonnes. A tonne of shipping fuel contains 0.85 tonnes of carbon, which produces 3.1 tonnes of carbon dioxide when it is burnt. Every passenger is responsible for 9.1 tonnes of emissions.82 Travelling to New York and back on the QEII, in other words, uses almost 7.6 times as much carbon as making the same journey by plane.
Short-haul shipping could be even worse. An initial calculation Roger Kemp made for a car ferry to Norway suggests that at 48 kmph the carbon emissions per kilometre are roughly twenty times greater than those produced by a train travelling at 200 kmph and several times greater than a plane’s.83 Again, car ferries are an inefficient means of shifting people, as the vehicles they carry weigh more than the passengers; even so, his estimate gives us further cause to be gloomy about ships. There are some technical measures – such as designing the hull to create air pockets or coating it with slippery polymers,84 or using a ‘towing kite’85 – which could reduce a ship’s emissions; but most are speculative and, it seems, their possible applications are limited. Unless we are prepared to travel very slowly, as much of our freight does, shipping is not the answer.
Becoming rather desperate now, I have looked into airships: craft kept aloft by gases that are lighter than air. In some respects they are quite promising – according to the Tyndall Centre, their total climate impact is 80–90 per cent lower than that of aircraft.86 (This is not the same as an 80–90 per cent carbon cut, however, as it takes into account the other emissions jet planes produce.) This could be improved with better engines or possibly even hydrogen fuel cells. Kevin Anderson of the Tyndall Centre points out that if they were suspended by means of hydrogen rather than helium, the gas could be drawn out of the ballast as they travel and used for fuel.87 This is quite a neat proposal. At present, airships become lighter as their fuel is consumed, and therefore harder to control. Anderson’s proposal, if workable, could allow them to retain roughly the same buoyancy throughout the trip. Despite the residual public memory of the Hindenberg disaster, they appear to be safe. They have a range of up to 10,000 kilometres. But, though faster than ships, their top speeds are currently confined to around 130 kmph: a flight from London to New York would take about 43 hours. They also have trouble landing and taking off in high winds and making way if the wind is against them. This makes both take-off times and journey times less reliable than those of jets. But if we really have to cross the Atlantic, and we are to prioritize the reduction of carbon emissions, airships, surprisingly, might be the best kind of transport.
But now I really have run out of options. Not only is there no means of cutting emissions from planes to anything resembling the necessary level, but there is no form of transport which achieves much more than a quarter of their speed without producing comparable quantities of carbon. There is simply no means of tackling this issue other than to reduce the number, length and speed of the journeys we make.
If we were to overlook the additional climate-changing effects of flying and assume – perhaps optimistically – that a 20 per cent improvement in fuel efficiency is possible by 2030, we would need to cut the number of flights we make by 87 per cent to meet my target. But if we take the other climate impacts into account, and remember that fuel efficiency is likely to be counteracted by vapour formation, we must cut flights by over 96 per cent. If long-range propeller planes took the place of jets, however, and flew below the level at which condensation trails are formed, we might be able to get away with a smaller reduction. The alternative is to cut the carbon emissions produced by other parts of the economy by more than 90 per cent in order to accommodate a greater contribution from flying. To do this, we would have to argue that flying is more important than heating or lighting. As it is practised only by those who are – in global terms – rich, this argument would be difficult to sustain.
Again I feel I should remind you that this is not an outcome I have chosen. If you don’t like it, you must find a means of proving me wrong, and it had better be more persuasive than the proposal to transport people by means of cosmic energy that one of my readers sent me.
So I offer you no comfort in this chapter. A 90 per cent cut in carbon emissions means the end of distant foreign holidays, unless you are prepared to take a long time getting there. It means that business meetings must take place over the internet or by means of video conferences. It means that trans-continental journeys must be made by train – and even then not by the fastest trains – or coach. It means that journeys around the world must be reserved for visiting the people you love, and that they will require both slow travel and the saving up of carbon rations. It means the end of shopping trips to New York, parties in Ibiza, second homes in Tuscany and, most painfully for me, political meetings in Porto Alegre – unless you believe that these activities are worth the sacrifice of the biosphere and the lives of the poor. But I urge you to remember that these privations affect a tiny proportion of the world’s people. The reason they seem so harsh is that this tiny proportion almost certainly includes you.
Recognizing that it was possible for a human being to fly; then that it was possible for a human being to fly long distances; then that it was possible for many humans to do so; then that it was possible for you to do so, required a series of imaginative leaps. It required the construction by the people of the twentieth century of a possible world which did not exist before. No one in Europe ever thought of shopping in New York or visiting friends in Australia before planes allowed them to do so. Recognizing that while it is still possible for a human being to fly, it will no longer be possible for many humans to do so, indeed that it will no longer be possible for you to do so, requires a similar series of imaginative efforts. But if it was possible to construct one alternative world, it is surely possible to construct another, and to adjust ourselves to that world (scarcely conceivable as it now seems) just as we adjusted to the other – even less conceivable – existence.
I do not pretend that this will be easy, or that my finding will win me any friends. Those whose freedoms must be curtailed happen to be members of the world’s most powerful classes. Worse still, they happen to be us. The promises we have been made – of tropical sunlight in the dead of winter, of one-week safaris in the Maasai Mara, of heroic missions to rescue the bridgeless people of the Peruvian Andes, of the sampling of pleasant fruits and princely delicates throughout the new-found world – have shaped our expectations, the pictures we carry of our future lives. We have come to believe we can do anything. We can do anything. Accepting that we no longer possess the powers of angels or of devils, that the world no longer exists for our delectation, demands that we do something few people in the rich world have done for many years: recognize that progress now depends upon the exercise of fewer opportunities.
Rationing alone will not make all the necessary decisions for us. If airport capacity is permitted to keep expanding, indeed if it is not deliberately reduced, then flying will break the rationing system just as it will, on current projections, break the Emissions Trading Scheme. The gulf between what we could do and what we should do would simply be too great: the political clamour to expand the allocation to permit us to make use of the growing opportunity insuperable. Even before a rationing scheme is in place we must lobby for a moratorium on all new runways. This campaign in many rich nations – including the United Kingdom – has already begun. Climate-change campaigners have joined forces with the people who live close to where the runways might be built, who fear that their lives will be ruined.88,89
I have sought the means of proving otherwise, not least because it would make my task of persuading people to adopt the proposals in this book much easier. But it has become plain to me that long-distance travel, high speed and the curtailment of climate change are not compatible. If you fly, you destroy other people’s lives.