Modes of transport and distances travelled

November 26, 2008

in Economics, Science, The environment, Travel

Adding once again to our ever-present debate about the ethics of air travel, a study from the University of California, Berkeley concludes that the major reason planes are more problematic than trains or buses is that people simply travel farther in them. This has two major implications.

For one, it suggests that efforts to curtain short-haul air travel may have limited benefits. If a high-speed rail corridor between Toronto and Montreal would only lead to incremental improvements in emissions reductions, the better course may be to try to discourage as much travel as possible. This may be especially true given another major conclusion of the study: that a very significant share of the environmental impacts of travel arises from the infrastructure (roads, rails, airports), rather than the emissions of vehicles themselves.

For another, it suggests that investing the time and money to travel by bus or train may likewise be less green than would be ideal. The problem may not be choosing to go from Ottawa to Vancouver by air; it may be an inescapable problem of making the trip in the first place.

It is well worth having a look at the webpage for the study, as it contains a lot of additional information. The study’s conclusions were also described on Slate.

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{ 23 comments… read them below or add one }

Tristan November 26, 2008 at 8:48 am

Looks like a very comprehensive account. I appreciate that they include infrastructure components – road construction is too often left out of CO2 calculations.

However, this story tends to make me believe that private autos are the most potentially green form of transportation, because they have the most improving to do. It is possible that aircraft travel could become perhaps 100% more efficient with radical changes, and rail travel on incrementally so (a switch to renewable energy would be significant only if the marginal electricity were being generated by a renewable, and so far I am not aware of any switchable renewables). However, it is very realistic to assume that we might purchase and use autos tree times more efficient than the current Toyota Camry, because the reality of auto sales has been more influenced by cheap oil and the need to sell cars by image and performance than by a need to be economical.

The point I want to make is not so much prove that there already exist 100mph cars that we can buy (although this is almost the case) (no, not hybrids), but rather that there is so much inefficiency built into the modern auto that it has to have much more room to improve than the modern train or the modern airliner.

Furthermore, however many people are in the car, there could probably be a few more. If we could work out a fair and safe system of hitchhiking, we could create a lot of extra transportation for almost no extra cost.

. November 26, 2008 at 11:17 am

A few interesting sections from the final methodology and results:

“We find that life‐cycle energy inputs and emission outputs increase significantly compared to the vehicle operational phase. Life‐cycle energy consumption is 39‐56% larger than vehicle operation for autos, 38% for buses, 93‐160% for rail, and 19‐24% for air systems per passenger mile traveled. Life‐cycle greenhouse gas emissions are 47‐65% larger than vehicle operation for autos, 43% for buses, 39‐150% for rail, and 24‐31% for air systems per passenger mile traveled. The energy and greenhouse gas increases are primarily due to vehicle manufacturing and maintenance, infrastructure construction, and fuel production…

The social costs of travel range from $0.51 (in 2007 dollars) per auto passenger per trip during peak in New York to $0.06 per public transit passenger per trip during peak hours in the Bay Area and New York. Average personal transit costs are around $0.30 while public transit ranges from $0.28 to $0.41…

The societal costs associated with different types of travel in different regions vary significantly but are all considerable if internalized by the trip takers. For the average trip, the life‐cycle health and GHG costs per passenger per trip are ¢28 for the Bay Area, ¢27 for Chicago, and ¢30 for New York (all costs are in ¢2007). It is assumed that the emissions that occur from transport in each region are more likely to have high impacts since they occur in densely populated areas and thus using the associated healthcare costs is reasonable…”

. November 26, 2008 at 11:19 am

Aircraft Operation

The cruise phase accounts for between 55% (Embraer 145) and 74% (Boeing 747) of total energy consumption and GHG emissions. The other operational components (APU, startup, taxi out, take off, climb out, approach, and taxi in) make up between 4% (Boeing 747) and 27% (Embraer 145) of total energy consumption and GHG emissions. The fuel and associated GHG emissions of an average 19 min taxi out show as a major component in final results. Additionally, the climb out and approach stages also show as major contributions.

Aircraft Manufacturing

The impacts of aircraft manufacturing are significant for all aircraft but are most noticeable with the 747. For this aircraft, manufacturing energy consumption and emissions are about 43% larger than non‐cruise operational emissions and 6% of total. The lowest manufacturing emissions (per PMT) are experienced with the 737. Given the medium‐range nature of its flights coupled with manufacturing requirements, which are significantly less than the 747, leads to a comparatively low factor.

Fuel Production

For every 100 units of jet fuel produced, an additional 16 units are needed (in both direct and indirect supply chain support) [EIO‐LCA 2008, SimaPro 2006]. Given that operational phases dominate aircraft energy and GHG emissions, the 16% fuel production component increase is a direct major contributor to energy and GHG inventories. Fuel production is about 8% of total energy consumption for all aircraft. With GHG emissions, approximately 10% is attributable to this component.

GHG Life-cycle Inventory
GHG (g/PMT) (operational emissions in parenthesis)

Embraer 145 – 290 (230)
Boeing 737 – 210 (170)
Boeing 747 – 200 (150)

Milan November 26, 2008 at 11:36 am

Looks like a very comprehensive account. I appreciate that they include infrastructure components – road construction is too often left out of CO2 calculations.

It is definitely comprehensive. I do wish they had more clearly separated the climate change related social costs from the social costs associated with other forms of pollution. Ethically, they strike me as rather distinct. Particulate matter, carbon monoxide, and the like have immediate effects on those living today. Most of the harm caused by greenhouse gasses will impact future generations.

However, this story tends to make me believe that private autos are the most potentially green form of transportation, because they have the most improving to do.

Pretty much any form of travel could be made a lot more ‘green’ – though the extent depends somewhat on what scale of travel you want to have and which environmental impacts you care about. Reducing the climatic impact of vehicles can be done through any combination of increasing their efficiency and decreasing the carbon intensity of their fuels.

You could have cars that run entirely on renewably generated electricity when in the city and run on biofuels when outside cities. That would at least be carbon neutral, though there would be environmental impacts associated with car and road manufacture, renewable generation, and biofuels production. Trains could likewise be run on green electricity and biofuels, while planes could only be made carbon-neutral by burning 100% biofuel, which may or may not be technically or economically feasible in the medium term.

I agree that cars could be made dramatically more efficient. That being said, I still think we need to consider the possibility that a carbon-constrained future will involve a lot less travel altogether. Just think about the land-intensity of renewables and biofuels compared to oil. If those are the technologies we need to transition to, there may be a lot less total energy available for transport in the future.

a switch to renewable energy would be significant only if the marginal electricity were being generated by a renewable, and so far I am not aware of any switchable renewables

I don’t see why this is true. Firstly, there are ‘switchable’ renewables, if you mean by that those that can vary their output voluntarily. Key examples include hydroelectric dams (especially those with pumped storage capability) and thermal plants that run on biomass. It is also quite possible to use periods when intermittent renewables are generating power (because the wind is blowing, sun is shining, etc) to charge batteries, pump water uphill, or possibly produce hydrogen. Finally, there are renewable options capable of providing baseload power equivalent to that from a coal or nuclear plant: such as geothermal plants and concentrating solar plants with thermal energy storage.

It isn’t the marginal kilowatt-hour that matters, in terms of the carbon intensity of electricity production: it is the greenhouse gas intensity of each kilowatt-hour in the mix. If you have, for instance, electricity that is 50% hydroelectric, 20% nuclear, 10% renewable, and 20% fossil-fuel fired, the total emissions associated do not depend on which plant you turn on last.

Milan November 26, 2008 at 11:42 am

The GHG lifecycle inventory for air travel in this report is surprisingly low.

It lists the Boeing 737 as producing 210 grams of CO2 per passenger mile travelled. Since Ottawa and Vancouver are 2200 miles apart, that corresponds to just 462kg of carbon dioxide each way.

By contrast, the Native Energy calculator projects that the trip produces 880kg each way, and I don’t think they try to take into account lifecycle costs like aircraft construction. The Planetair calculator comes up with 780kg each way, when a 2x multiplier is applied for ‘high altitude impacts.’

Sarah November 26, 2008 at 4:03 pm

The problem may not be choosing to go from Ottawa to Vancouver by air; it may be an inescapable problem of making the trip in the first place.

Sure. However, Canada is the second largest country in the world, so this problem may not be generalisable i.e. when travelling from one side of a smaller country to another (eg. London to Fort William, or Paris to Toulouse) the crucial question may be the means of transport and not one’s decision to travel or not. Without air travel, Canada is essentially too large and too sparsely populated to be effectively governable (which is the fault of my country people for not dividing it up).

For one, it suggests that efforts to curtain short-haul air travel may have limited benefits.

Wikipedia tells me that definitions of ‘short haul’ range from under 1.5 hours to under 3 hours, which is a huge range and means that dissimilar journeys are being lumped together. My trip from London to Istanbul was under 3 hours and would be pretty difficult to do by land because a) it is a long way, b) so many international borders are involved, and c) there is no longer an Orient Express train. On the other hand, a trip from the UK to France or Ireland can be quickly and easily be done by combinations of car, ferry and train, so in those cases I would certainly favour restricting flights. The validity of your conclusion also depends on whether alternative means of travel already exist – if there is a train line or highway already then the calculation will be very different than if that infrastructure doesn’t exist.

Litty November 26, 2008 at 4:50 pm

This certainly seems like a thorny issue… heh heh heh

Milan November 27, 2008 at 4:23 pm

Sarah,

when travelling from one side of a smaller country to another (eg. London to Fort William, or Paris to Toulouse) the crucial question may be the means of transport and not one’s decision to travel or not

I don’t see how this is the case. If the study is correct and the most important difference between flying and alternative modes of travel is that people tend to travel farther by air, there are small gains to be made in switching people from planes to trains or buses regardless of the size of the country in question. Any incremental gains do get multiplied more over the course of longer flights, though the differences in travel time between planes and alternatives increase as well.

Without air travel, Canada is essentially too large and too sparsely populated to be effectively governable (which is the fault of my country people for not dividing it up).

It was effectively governed without air travel for quite some time.

Given modern communication technology – as well as the degree of authority delegated to provinces – I don’t see how Canada’s governance is an argument for more air travel.

The validity of your conclusion also depends on whether alternative means of travel already exist – if there is a train line or highway already then the calculation will be very different than if that infrastructure doesn’t exist.

Very true.

Lots of factors come into play when considering the morality of any trip. They seem to fall largely into two categories: (a) how necessary the trip is and (b) how much effort was taken to travel in an ethical way. Obviously, getting flown from the site of an accident to a hospital is more ethically acceptable than flying off on vacation or to see family members. Likewise, travelling by means that cause less harm to other people is superior to travelling by more harmful means. Even purchasing credible carbon offsets may have a significant effect on the moral calculus associated with any particular journey.

. December 12, 2008 at 3:02 pm
. March 25, 2009 at 4:13 pm

In Praise of the Lowly Bus
By Clark Williams-Derry

Sustainable transportation geeks give trains lots of love, but tend to overlook buses. That’s a mistake: buses are surprisingly green. This report, for example, finds that buses are pretty much the most fuel efficient way to travel between cities — better, on average, than rail, cars, or airplanes.

Of course, you can’t just trust one report — especially one that was funded by the American Bus Association. But plenty of other people have found the exact same thing. Our research on greenhouse gas emissions per mile of travel found that inter-city buses have the lowest climate impact of any form of travel. Rhe authors of the Consumer’s Guide to Effective Environmental Choices — which is a bit out of date now, but still excellent — found the same thing. So did the Environmental Defense Fund. I could go on; but the bottom line is that people who care about sustainable transportation find that intercity buses are a pretty good deal for the climate.

Milan October 26, 2009 at 1:33 pm

Here is a nice demonstration of how improvements in airline efficiency are fairly incremental, and how the total impact of flying remains large.

Milan October 26, 2009 at 1:34 pm

Regarding cameras:

I considered buying a used 20D at Henry’s, using it for the 4-6 weeks, and then selling it back to them.

Unfortunately, while they sell the 20D for $550 in “as new” condition, they only pay $200 for them. $250 may well be less than the cost of renting a camera for that duration, but it is still more than I think I should spend.

. February 15, 2010 at 10:44 am

“The controversy stems from the fact that high-altitude emissions – from nine to 13 kilometres up for subsonic flights and higher for supersonic – cause disproportionately more warming than those at ground level, anywhere from 50 per cent to four times as much, making its global-warming role more significant than its emissions tally alone would indicate.

Part of the worry is due to contrails, the thin vapour trails from jets that crisscross the sky above many of the world’s most-travelled air routes. Contrails resemble artificial cirrus clouds, trapping heat, although there is no scientific consensus about the size of their leavening effect on global warming.

Air travel was given a little-publicized loophole in 1997 under the Kyoto Protocol, one of only two industries, the other being shipping, exempt from the greenhouse-reduction pact. When the protocol was negotiated, there was no agreement on who should shoulder responsibility for emissions due to international travel.”

. May 18, 2010 at 11:44 am

MIT Designs Aircraft That Uses 70% Less Fuel Than Conventional Planes

“Today a team of researchers at MIT unveiled their design for an airplane that uses 70% less fuel than conventional aircraft. The MIT design comes thanks to a NASA-funded initiative to increase fuel efficiency, lower emissions, and allow planes to take off on shorter runways. The team accomplished all of NASA’s set goals with their innovative D-series plane, lovingly referred to as the ‘double bubble,’ which has thinner, longer wings and a smaller tail, and engine placement at the rear of the plane instead of on the wings.”

. May 18, 2010 at 2:15 pm

When construction is taken into account, high speed rail journeys from London to Manchester will produce 60% more carbon than conventional rail and 35% more carbon than car journeys. They will generate only 25% less carbon than plane trave.

Throughout the recent government documents there’s an assumption that the new railway will be sustainable because it will draw people out of planes. But buried on page 162 of the report on which the department has based its case, published in March 2010, are the figures which derail this assumption. Of the passengers expected to use the new railway, 57% would otherwise have travelled by conventional train, 27% wouldn’t have travelled at all, 8% would have gone by car and 8% by air. In other words, 92% of its customers are expected to switch to high speed rail from less polluting alternatives. Yet the same report contains a table (page 179) suggesting that the savings from flights not taken outweigh the entire carbon costs of the railway. It provides neither source nor justification.”

Milan September 3, 2010 at 3:49 pm

It has been 2 years, 8 months, and 1 day since last time I flew: from Vancouver to Ottawa.

Since then, I have done quite a number of trips by bus:

  • Toronto (April 2008)
  • Toronto (May 2008)
  • New York (July – August 2008)
  • Vermont (July – August 2008)
  • Montreal (July 2008)
  • Toronto (September 2008)
  • Toronto (October 2008)
  • Toronto (November 2008)
  • Vermont (December 2008)
  • Toronto (January 2009)
  • Toronto (April 2009)
  • Toronto (June 2009)
  • Vancouver (December 2009 – January 2010)
  • Montreal (Easter 2010)
  • Vermont (April 2010)
  • New York (August 2010) -via Bennington, Vermont

On a rough estimate, that’s about 353 hours of Greyhound time. That’s 14.71 days. About 44% of that was my round trip from Ottawa to Vancouver.

. November 1, 2010 at 3:48 pm

While a commercial jet costs anywhere between $40 million and $200 million, the cost of fuel is, in fact, a bigger issue for airlines. It’s risen to become airlines’ highest fixed cost, eating up 30 percent to 40 percent of their operating budgets, even with hedging. It’s Boeing’s job to come up with jets that burn less fuel, which it’s aiming to do with its forthcoming 787 series through extensive use of composite materials instead of aluminum. Rollout of the 290-seat 787 has been delayed several times, and it is currently scheduled to take to the air sometime in the first quarter of next year. (All Nippon Airways is the first customer.) Boeing’s Warner says the 787 will consume 20 percent less fuel than the planes it replaces, but that ambitious goal is part of what’s causing the delay; engineers have gone through rounds of tweaking and retesting to make the 787 lighter and use lighter-weight materials in construction. Howard Rubel, an analyst with investment company Jeffries, suggests that the government could step in with tax credits or other incentives to further R&D efforts, for Boeing as well as the network of smaller companies that manufacture aircraft components.

. January 6, 2011 at 11:46 pm

Angry passengers still not sure why Greyhound stranded them

By Sarah McGinnis, Postmedia News

CALGARY — Frustrated passengers pulled into Calgary on Tuesday morning after being stranded on a Greyhound bus in northern Ontario for 14 hours with no explanation of why they’d been left.

Paul Hitchin, 29, was to report for work in Calgary on Monday morning.

Everything seemed fine as he travelled from Barrie, Ont., by bus until around 3 a.m. Sunday, when the bus stopped in a parking lot in White River, Ont. — a community of about 1,000 people about 390 kilometres east of Thunder Bay.

“The bus driver said, ‘Looks like bad weather. Sit tight,’ and then he just left,” said Hitchin.

Passengers in the packed bus found themselves waiting from 3 a.m. Sunday until around suppertime before they were moving again.

In that time, Hitchin says they had next to no word from the bus drivers or Greyhound on why they’d been abandoned, nor were they given any place to sleep or anything to eat.

. January 18, 2011 at 10:43 pm

Sailing on the green seas

SIR – The subtitle to your article on ships as polluters read: “Ships are filthy. A new website shows how filthy” (“Smokestack lightening”, December 11th). Shipping transports about 90% of the world’s trade and emits 2.7% of the world’s emissions. The per tonne of cargo transported by a very large crude-oil carrier of about 310,000 tonnes capacity is 153 times more energy efficient per tonne of cargo than a Boeing 747-400, 63 times more energy efficient than a small truck, 14 times more energy efficient than a large truck and five times more energy efficient than a train. This simple fact should have caused you to question the information on which you based your article.

Shipowners or operators have every incentive to economise on fuel consumption, considering fuel represents a very large proportion of the overall transport cost, but they do not design the ships. Every ship on the market wanting to secure employment is advertised with its deadweight capacity, speed and consumption clearly stated for all to see. Transparency in shipping is not an issue.

George Gratsos
President
Hellenic Chamber of Shipping
Piraeus, Greece

SIR – Thanks largely to technological developments and industry practice the energy efficiency of ships is some 20% higher than in the 1970s, which means ships burn less fuel and generate less emissions. To further reduce greenhouse-gas emissions from ships, the International Maritime Organisation’s marine environment protection committee has developed a robust package of ship design and operation measures that are ready to be enacted as international maritime law. These could achieve reductions of up to 75% in ships’ emissions and would be the first regulatory package adopted by any industrial sector at the global level.

Jo Espinoza-Ferrey
Head, policy and planning unit
International Maritime Organisation
London

. April 5, 2011 at 11:03 pm

Finally, Dan Lusina introduced me to the greatest number since Pi: 0.00269094. That is the emission factor for diesel, every passenger bus’s favourite fuel. It is the number of metric tonnes of Carbon Dioxide equivalent (Greenhouse Gases) emitted per liter of diesel burned.

So the equation looks like this: 0.00269094 / 2.98 x (number of kilometres travelled) x (number of buses in entourage) = Metric Tonnes of GHGs emitted

Again, many thanks to Dan. I never would have been able to do this by myself. The irony here is that buses are way less polluting than planes and the leaders travel far smaller distances in them. So I did all this math for some tiny little numbers. Such is life.

. June 10, 2011 at 8:31 pm

The Megabus Effect

After decades of decline, the bus is the U.S.’s fastest-growing way to travel, led by curbside service from Megabus, BoltBus, and others

On a Chicago morning in late December, 60 people are lined up outside along a downtown street, waiting for buses headed to Des Moines, Indianapolis, and Kansas City. It’s 20F, the wind talons, and the travelers sway and stamp. A student of clinical psychology at the University of Illinois at Chicago, standing near four dreadlocked white guys, says he paid $26 for a 200-mile trip to Iowa City, which prompts someone else to brag that his seat on the same double-decker bus cost $5.

They’re all there to catch rides offered by Megabus, the largest of the private companies to corporatize New York’s “Chinatown bus” model of street-side pickup, express travel between sizable cities, and cut-rate fares. Half a mile from the Greyhound depot and barely on the periphery of Union Station’s Beaux Arts grandeur, the Megabus stop’s only identification is a modest street sign displaying the company name above its mascot, a cherubic, Benny Hill-like character in a yellow driver’s cap.

. July 18, 2011 at 7:11 pm

Carmageddon Challenge
Can Los Angeles cyclists beat a plane from Burbank to Long Beach? How my idle tweet spawned an epic transportation showdown.
By Tom VanderbiltPosted Friday, July 15, 2011, at 5:26 PM ET

. September 21, 2011 at 9:12 pm

Gliding distance is an imperfect measure of an airliner’s aerodynamic efficiency, since it is not designed for gliding. But the Gimli Glider incident, as it became known, helps illustrate the magnitude of advances in aviation technology. Improved efficiency means that Boeing’s new 787 airliner consumes about 40% less fuel per passenger than its 1970s aircraft. Airbus and other manufacturers have achieved similar results.

On most passenger jets, the wings and fuselage generate about 90% and 10% of the lift respectively. Working with funding from NASA, aerospace engineers at the Massachusetts Institute of Technology (MIT) have designed an aeroplane with a body so fat, and wings so narrow, that the fuselage provides about a fifth of the aircraft’s lift. Its cross-section resembles that of two partially joined bubbles. The “Double Bubble”, as it is called, looks awkward, but the team estimates that its design would reduce fuel consumption by about 70%. This is only partly because it would fly about 10% slower than today’s airliners.

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