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Have I discovered the world's most carbon efficient form of transport?

Justin Rowlatt | 18:22 UK time, Saturday, 16 January 2010

OK, I think we've cracked it. I've spent huge effort on this blog trying to work out whether any forms of transport are truly low carbon.

It is an important issue - almost a quarter of world greenhouse gas emissions are from transport.


I have explored the relative carbon cost of almost every type of transport you can imagine.

I have even analysed the environmental impact of walking - and found that on one reckoning walking is actually more polluting than driving!

The fact is there are no straightforward answers.

Flying isn't as bad as you might think - pretty much the same carbon footprint as driving (except of course you are likely to go a lot further on a plane) - meanwhile public transport might actually be less carbon efficient than just hopping in your car .

But now I reckon I've got the definitive answer. I have found the world's most ethical form of transport.

Here's how it happened:

My blog on why cars might be greener than public transport caught the eye of the FT's devilishly clever "undercover economist" Tim Harford, who moonlights here at the BBC as the presenter of the Radio 4 programme More or Less .

Average occupancy

The programme had snuffled out some statistics from the Department of Environment, Food and Rural Affairs which confirmed my claim.

The figures show that the average occupancy of a British bus is just nine people. Even in London a typical bus has just 13 passengers.


Two people in a car produce lower emissions per person than nine people in a bus.

Indeed, the figures show that buses are only 20% more efficient than taking the car based on average vehicle type and occupancy.

But that's not what had snagged Tim's interest. He was intrigued by a claim I made at the end of the blog.

I argued that it is always more carbon efficient to take the public transport option because "it will be going anyway".

'Perfect excuse'

He wanted to know whether the same argument applies to flying. If the reason you catch the bus is that it will be going anyway then surely that's also true of your holiday flight to Malaga - it will fly with or without you.

In short, it is the perfect excuse for us all to continue flying around the world.

But will the buses and planes be going anyway? That's what Tim wanted to know and he invited me and the Independent newspaper's travel correspondent, Simon Calder to discuss the question with him.

Simon Calder is known as "the man who pays his own way" and is quite possibly the most travelled man in Britain.

He is also, it transpires, a mathematician. In short the ideal person to discuss this tricky issue.

You can listen to the programme here:

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As our discussion demonstrates, the question is not as straightforward as it might first appear.

Are you actually responsible (at least in part) for persuading the bus, train or airline company to put on additional services?

Do you agree with Tim's argument that average marginal cost applies to buses and planes equally - or are you on my side?

(I should probably come clean here. I was very briefly an extremely junior economist at the Department of Transport. But don't let that affect your judgement.)

Impact of walking

You'll have heard from the programme that I suggest that for short journeys walking or cycling is preferable to even public transport, but my analysis of walking shows that it is actually pretty energy intensive - and the energy in our food tends to be pretty carbon intensive .

So what is the truly low carbon travel alternative? It was Simon Calder who suggested hitchhiking.

He says that his own personal offsetting scheme is to hitchhike wherever possible, arguing that hitchhikers do not generate additional traffic.


I think there a strong case for that. After all, the driver who picks you up at a service station on the M62 or on the verge of the A43 is extremely unlikely to have decided to hop in his car with the intention of picking up a hitchhiker (if he has I venture to suggest you are in real trouble).

What's more the additional carbon cost of you travelling with him will be very low.

I asked Simon why I hadn't seen him standing sodden in the rain at the end of the M1 and he said that's because now he's finally got rid of the German army greatcoat he wore as a teenager drivers readily pick him up.

But does anyone else hitchhike these days? You certainly see very few hitchhikers on the roads.

Festival flashback

I haven't hitchhiked for years but I can certainly remember my hitching days, and my best journey. That was heading to the Glastonbury festival back in the summer of 1986.

My friend Tim and I turned up at the end of the M4 and there were already 20 to 30 shaggy festival goers there already. Hitchhiking etiquette required that we join the end of the queue.

At this rate we wouldn't be at the festival until after Level 42 had played their set on the famous pyramid stage on the Sunday. (That's right, Level 42 were a headline band at Glastonbury - and people made a fuss about Jay-Z!).

But minutes later a lorry pulled up and said he'd take us all. We bundled into the back and sat on our sleeping bag rolls and rucksacks passing round the cider all the way to Somerset and were there in time to see The Cure (not to mention Lloyd Cole and The Pogues).

Not bad eh?

Do you have a better hitching story?


  • Comment number 1.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • Comment number 2.

    Just over a year ago I hitchhiked from Toronto, Canada, to Panama City in Panama. It took a little over a month and it was mind blowing.

  • Comment number 3.

    "You'll have heard from the programme that I suggest that for short journeys walking or cycling is preferable to even public transport, but my analysis of walking shows that it is actually pretty energy intensive - and the energy in our food tends to be pretty carbon intensive."

    Justin, have you started doing a (junior level) economic analysis of the carbon-footprint of the NHS bed that you might one day occupy by not doing more walking?

    I'm delighted that you are consorting with a mathematician. Now add in some physicists and chemists, biologists, cardiologists....

    Unfortunaqtely your moniker of "ethical" man doesn't even make me laugh.

  • Comment number 4.

    The silly thing going on here is that you're analyzing purely on the individual action, not the aggregated effect of individuals choosing their actions. To dissuade people from taking public transit on the grounds that it doesn't have the best passenger ratios (that is, not enough people are riding) is asinine. Transit becomes more efficient with greater ridership. Yes, high ridership may influence an increase in service, but at that point there are also great social benefits to consider.

    Hitch-hiking is a fine decision for an individual to take, but there has to be a certain number of people already driving inefficiently for that form to exist. I would also argue that it has fewer social benefits as a system, because it does not necessarily increase mobility for many marginalized groups-- elderly women of weak physical ability, parents on tight schedules, etc.

  • Comment number 5.

    Your assumptions about walking are based on maintaining the same lifestyle that you used to have ten years ago as a committed driver, and eating as much food as you burn to walk, plus adding footwear or other gear.

    The mostly-walking lifestyle we fell in for when we lived without a car for eight years in Northern California was nothing like what you described. We also used the opportunity to lose weight. My husband lost 60 pounds; I lost 20; our youngest, a "normal" teen lost about 25 and got tall & lean & very fit.

    We did not add more food to make up for the calories being burned. Quite the contrary: we used walking as they gym and the reason for getting back into the shape we wanted to regain. My husband at almost 59 has the body of a fit man half his age now.

    For eight years, we bought no gym memberships and no auto insurance. We never owned more than five pairs of shoes per body (including 1 pair of trainers per person) during that time. On the rare occasion we absolutely had to drive, we used a car-share service. Total spent on that was about $3000 over the four years.

    Yes, we used public transport, but since it is time-consuming & generally unpleasant in the US, we kept that to a minimum, as well. We basically reoriented all our lives, staying much closer to home. Only began flying overseas again when it became essential to do so.

    When you have to carry your food and drink home in your arms, your approach to shopping & eating also changes. You reduce waste; you tend to become less impulsive. An added benefit is that your offspring get a completely different view of the effort involved in providing for their basic needs.

    While someone who is at their optimal weight might feel compelled to fuel up more with calories after a long walk, honestly, a significant share of the grown amongst us, in any country, could actually stand to burn some of that stored fat. And I have found, beginning right around my 40th birthday, that I do just fine on 1100 calories a day, with the occasional vitamin thrown it, a varied & carefully balanced diet -- provided I also allow myself to get as much sleep as my body & mind ask for. Of course, in a cold climate, more food calories will be needed. But then, in a cold climate, you do have a good reason to use all manner of conveyances more. Not so when the weather is clement, warm & bright!

  • Comment number 6.

    Justin Rowlatt.

    "The figures show that the average occupancy of a British bus is just nine people. Even in London a typical bus has just 13 passengers. Two people in a car produce lower emissions per person than nine people in a bus."

    "So what is the truly low carbon travel alternative? It was Simon Calder who suggested hitchhiking."

    it was also S Calder who told us how Nicaraguan public transport (bus) works, ie does not depart until fully occupied, but this was not explored, how convenient.

    IF we weren't so obsessed with 'time is money' and allowed for a certain amount of flexibility in scheduled departures, bus journeys -- especially in London and other large cities -- would have higher average passenger numbers.

    combined with stiff fines on people who drive alone in their cars (check out Singapore) and there'd be change.

    like so many of your previous posts on an environmentally aware life-style, there's simply no evidence of you ever thinking 'outside the box'.

    at least you're having fun, well done.

  • Comment number 7.

    The most efficient form of transport ever devised is clearly the bicycle. The cost to ride a bicycle is so close to nothing at all. And when your brakes fail, you do not pay $800 for repairs -- you buy new brake pads for fifty cents. Furthermore, the health benefits of riding a bicycle are immense, greatly outweighing the negligible cost of riding. Just factor in all the health costs that you will not have to pay and you will quickly realize that a bicycle is better than free -- it literally pays you to ride that bicycle.

  • Comment number 8.

    Ah, Glastonbury '86 - such fond memories. Madness reading out the World Cup scores during their set. Seeing Maradona's Hand of God on a crusty's tiny portable TV monitor with 50 of us craning our necks. I hitched to that one too!

    Now living in Cambodia I've pretty much gone native. My usual mode of travel is as one of 3 people scrunched onto a 50cc moto. 100cc if we're lucky. Half the population eke electricity for their homes out of car batteries; I'm developing a business selling a simple product that doubles the life-time of the battery charge. I'd be wasting my breath marketing it on the basis of 'save the planet' - the message Cambodians earning $1 per day want to hear is 'save money'.

    And therein lies your answer. If you want to be carbon efficient don't be ethical - be poor.

  • Comment number 9.

    " Two people in a car produce lower emissions per person than nine people in a bus. "
    What about infrastructure? The infrastructure required for people to drive their cars (vast amounts of carparking and roads) far outweighs the cost and emissions of travelling. Attempts to reduce carbon footprint of travel without looking at required infrastucture of that transport and consequent costs and effects (the land devoted to cars requires ALL trips around cites to be longer, the congestion created by cars slows ALL other land transport, not to mention health costs etc.) are therefore meaningless. The infrastructure required for any other mode of transport in comparison to cars is miniscule by comparison. Also I would hazard a guess that "cruising" (searching for carparks made hard to find by underpricing of carparking) creates more carbon than all bus trips put together.

  • Comment number 10.

    A superb example of "reducto ad absurdum". Honestly, are you seriously suggesting people to consider hitchhiking as a way of travel?
    I did my own calculation. The answer was: abandon the cities and go back to the forests.(Yeah, did that after seeing Avatar)
    I feel guilty of using up my carbon credits by typing this.

  • Comment number 11.

    Good article, at least it makes people question conventional wisdom. We need to bring in compulsory insurance for cyclists though, especially as so many of them drive illegally (in Lincoln at least 2 lunatics for every good cyclist ride with no hand signals, through red lights, too fast on the pavements or at night with no lights. But then maybe if the police were to fine them for it they'd become better citizens.

  • Comment number 12.

    Having read the article and those referenced within it, I was glad to see that you had covered the petro calories involved in creating our food. Too many people neglect this when writing on the subject. As you pointed out in the other article, the vegan diet left you low on haemoglobin so what is the answer? The elephant in the living room is the burgeoning population in the developing world. There are far too many people, and while Europe's population without immigration would be falling, South Asia's, and Africa's are exploding. Ethiopia now has twice as many people as it did when the famine struck in 1985. This is what we must tackle - as well as stopping waste and needless extravagance. If every Briton followed every bit of your advice for ever more, the savings would be eaten up by the population explosion in the third world in five years. That is the reality. You are I am afraid preaching to the wrong people.

  • Comment number 13.

    Funnily enough I was thinking about this very point recently. In the 80s there would be a queue of (primarily) students at the start of the M1 near Brent Cross. I almost never see hitchhikers now, and if I do they are standing in a position where I would endanger other road users to pick them up. I don't think people trust other people any more to hitchhike.

  • Comment number 14.

    "You'll have heard from the programme that I suggest that for short journeys walking or cycling is preferable to even public transport, but my analysis of walking shows that it is actually pretty energy intensive"

    In that throwaway remark was your only reference, in your entire article, to the most efficient form of transport on the planet - the bicycle. Why? Is it because it's to obvious? Too practical? Too cheap? Because if people took to using it in huge numbers (as used to to be the case in China) we'd hardly have any cars and a huge fossil fuel consuming and dependent industry might then be on the way out?

    Your 'solution' is laughable and frivolous because as you know, hardly anyone is going to do it! I've hitched and offered as well but with everyone convinced that every hitcher is a rapist or murderer these days it's not really going to happen. This is an article for the sake of filling space sadly.

  • Comment number 15.

    Calling all cyclists! (like comment 7). I would love to join you. The reason I dont any more, is riding my bike fills me with fear. Not just for my health, but also for my survival. Lots of cuts and bruises and a couple of cracked ribs is my tally for mixing it with vehicles on our roads. That's why I quit cycling.
    Justin: What is the carbon cost of cycling injuries and fatalities?

  • Comment number 16.

    Strange hitch-hiking stories? Here are my three strangest from the late 60’s/early 70s.
    1. From Darlington to London on the A1 and M1 with a film stunt-man in a manual Jaguar (as they were in the early 70’s), with his left arm and left leg in plaster, driving fast enough to feel the bends on the Motorway while telling me of his exploits.
    2.Hitching on windy A4 from Corsham to Bath with a man on his way to Glastonbury Festival with a long-haired wig claiming to be an SAS man who thought it fun to overtake as cars were approaching to test their “bottle”.
    3.Picked up at London start of M1 by a mouse-like travelling salesman who asked if I minded if he wasn’t fully dressed. (I thought the poor fellow was embarrassed by having no jacket and tie on) On my reply, “of course not,” he whipped off a towel I hadn’t noticed on his lap to reveal his manhood exposed and proceeded to play with himself while boasting that he had picked up a girl in similar circumstances “who didn’t seem to mind at all”. I declined his offer to take me cross-country to my exact destination in Potton.
    So maybe a note of caution to prospective hitchers: do make sure you travel with a companion.

  • Comment number 17.

    In response to the comment " As you pointed out in the other article, the vegan diet left you low on haemoglobin so what is the answer? "

    I know many vegans who have been vegan for years and years and are perfectly healthy. Veganism isn't by definition unhealthy by any means, but those who are new to it can need a little help in discovering how to do it healthily.

    Not to suggest that its likely for everyone to go vegan, but health is not a restriction to it (for most).

  • Comment number 18.

    " ....that average marginal cost applies to buses and planes equally - or are you on my side?”

    What a perceptive question. The debate should not be about sides it must be about substance. Clearly busses and planes are both public transport. Anyone who applies fundamentally different ways of analysis to compare two equivalent means of transport can only be interested in persuading people to buy into his prejudice and not interested in getting to the truth.

    Marginal costing is often misapplied with appalling consequences because it ignores a large amount of cost, which has to be covered somehow.

    A new bookshop opened up in my local town centre a year ago. Yesterday it was boarded up. Someone has lost a lot of money on their investment in a new shop however I am sure that the price they sold the books at was more than the price they paid for them. If you have to use the marginal argument to justify using busses then it is inevitable that busses cannot be the best strategic solution.

    Marginal costing is essentially a very short-term tool - it has no place in a long term solution.

    Dump the prejudice, used rigorous logic and them we may start to see the truth.

  • Comment number 19.

    Of course one consideration that may not have been taken into account by many figures is that of production and distribution. I have heard that the average car generates around half of all its carbon emissions during the manfacturing process, before the owner to be has driven a single mile, and I am sure similar carbon costs are incurred through public transport. The problem with the grams of carbon per passenger mile measure, therefore, must surely be that any form of transport becomes more carbon efficient the more you use it. Should we not also consider the carbon impact of having the posibility of choosing to drive, cycle or take public transport? While I agree with Tim Halford that this carbon cost must be shared across all the passengers of public transport- you could be the one who necessitates a new train or bus being built- I would guess that public transport makes more efficient use of this initial carbon outlay by providing a greater number of passenger miles per gram of carbon emitted during its construction. I wonder if any studies on this have been done?

  • Comment number 20.

    I haven't done much hitchhiking but a few years ago I tried it on Easter Island, and wound up travelling from one side of the island to the other on the open back of a fully loaded melon truck. Good times.

  • Comment number 21.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • Comment number 22.

    Having read the article and the comments - The summary is - anything we do as the human animal has an environmental impact. All the hand wringing and political squealing will not make the slightest difference on a world wide basis - as individuals we can choose to live without modern conveniences but there are many more millions who do not have the trappings of modern civilisation that are environmentally more destructive per capita. The simple unpalatable fact is that there are just too many people in the world vying for the finite resources available - the key to reducing environmental change is to go back 400 years and set population levels there. The discussion then becomes a whole lot more fundamental. Ask yourself the 5 Why's of your consumption of resources and you will find that your very existence is the reason for environmental change occuring - take away that cause [you] and the world will look wonderful for the next set of exploititive inhabitants.{what ever they may be?] Will you be voting for mass extermination or putting yourself forward for liquidation - "No?" Thought not - The whole issue is much bigger than not releasing Co2 into the atmosphere or pollution of fresh water or similar - it is about fundamental management of the human species - If anyone has an idea how that can be done then perhaps you should stand up now.Please be aware the last person to reputedly do this was nailed to a cross 2000 years ago - so it's not a simple task.

  • Comment number 23.

    regarding walking and carbon efficiency v fossil fuel based transportation.

    it seems to me the important issue is from were the carbon originates ie

    1) atmospheric carbon which is in the pool so to speak to which we are trying to reduce already, captured by plants during photosynthesis.

    2) previously locked carbon (fossils oil,coal) brought into the atmospheric pool

    I realize that food production involves carbon release from locked fossil carbon sinks (tractors, fertilizer) but I find it hard to believe that it is more then fossil fuel based transportation who's carbon input to the atmosphere is purely extra carbon to the atmospheric system from previously locked sources.

    yours sincerely Justin

  • Comment number 24.

    Since the great and the good are fond of preaching about carbon emissions to us, did anyone work out just how much carbon was emitted during the Copenhagen conference? You know, the one where the limo firms had to have more limos shipped in from Europe because so many of them were booked, and people arrived in private jets.

    My reckoning is that the conference purportedly seeking to save carbon emitted more of it than many nations do in an entire year.

    So my choice of transport is... drum roll maestro... whatever gets me there in the most convenient manner.

  • Comment number 25.

    I found funny that people in blogs say it is better do this and that and all very easy... because they are out of reality.Well they must write something :-) in their blogs.
    For example walking or cycling, these people say you should go to work like that, yes yes, but you must think that there are industries and companies that they ask as one of first priorities that people have a license and have a car. Personally I walk and cycle but this doesnt look impress companies when I write that in my job applications. So no car, no job.
    So it is not blaming people of not doing this or that, if you want a change, implementations in all levels should be done at the same time. Is it not easy "ethic man"?

  • Comment number 26.

    The problem with the Nicaraguan bus model, also seen in Sri Lanka, is that it assumes everybody is travelling from one terminus to another. It couldn't work in British cities as most passengers are picked up and dropped off along the route.

    I have no doubt that this figure of 9 or 13 passengers per bus is averaged over the whole day. Many routes run buses every 20 minutes from 0600 to 2200. Why? To allow for two driver shifts per day. If a load of drivers would be willing to be more flexible and just work a three hour shift in each of the morning and evening rush-hours, the average occupancy of each bus would rocket.

  • Comment number 27.

    We should start with the premise that humans have very low or practily no effect on global warming, or like they prefer to say now, climate change.
    The world has been warmer and the climate has changed much more drastically hundreds and thousands of years ago. We should still not pollute preserve and save natural resources, but without using this as a political plataform to impose taxes or more controls over the existing big brother/police state.

    I would suggest for all of you to watch this special from ABCNews

  • Comment number 28.

    Tom and Simon Sykes edited a great book of hitchers' tales called No Such Thing as a Free Ride. Hitching is the way to travel, and not nearly as dangerous as people make out. People are, generally, lovely. Even drivers.
    I hitched with a friend very successfully in London once. From Farringdon Road to Buckingham Palace in no time at all, one lift, having put our thumbs out on a busy city street. The guy even went out of his way to drop us off where we wanted.
    I'm not sure what good it would do environmentally if more people hitched though.

  • Comment number 29.

    I beg to differ on your claim of similar emissions per kilometre for flying and driving.
    Last summer, 3 of us travelled from Berkshire to Toulouse in a 40mpg diesel car. While away, we collected a friend who had flown out and so 4 of us shared the return journey. The direct emissions from our diesel use on this journey totalled around 600kg CO2. Emissions per passenger were therefore around 90kg one way.
    The friend who flew out on a BA flight (pretty empty) used 800kg CO2 for the one way trip, at a very conservative estimate. If we take radiative forcing into account the effective emissions would be around 2000 kg CO2e.
    I conclude from this little jaunt that driving my family to the Med and back again results in no more than one-tenth of the emissions that would result from taking the plane.

  • Comment number 30.

    Since when did life become about carbon emissions above all else? This is stupid. If you're so worried about carbon emissions do your bit by simply breathing less. Every time you exhale you release carbon dioxide, so do less of it to save the planet.

    So... before breathing count slowly with me... 1... 2... 3... 4... 5... 6... now breathe out. There, now you too can feel smug that you've saved some carbon emissions today.

  • Comment number 31.

    I suggest "hitch-hiking" a bus, coach or train would be even more efficient than hitch-hiking in a car. The bus, coach or train is going to its destination anyway (and more efficiently than the car), and if you don't buy a ticket then you aren't adding to the demand for the service.

  • Comment number 32.

    #26, great idea in theory but not that great for people who don't have cars but want/need to travel outside rush hours.

    It would seem to make more sense to have large double-deckers to carry lots of people at rush hour, and small buses for use during the day for when demand is so much lower.

    But, of course, how dare those selfish bus drivers want anything other than a three-hour shift, six hours during the middle of the day and then another three-hour shift? Why can't they sacrifice their own lives for the betterment of their comrades?

  • Comment number 33.

    My fiancee & I were hitching from the Trossachs and were picked up near Stirling by a driver who had 20 ton of raspberry pulp behind him. He also had a bag full of only the Quality Street purple wrapped hazel nuts in caramel in the cab!! This was something we had not come across in England - and my future wife's favourite!! It was around mid-day and he told us that we would arrive in Kendal about 6.15 pm.
    This was back in 1964. No motorways, no hold ups, we arrived in Kendal at 6.10 pm, in timely fashion to get to the YHA in time for dinner.

  • Comment number 34.

    I have the perfect solution why not use slides.
    This method would not only be fun but extremely efficient. what you would need would be a tower that takes you to the correct height for the distance you intend to travel. You would get to the top via lift and because lifts use a counter weight they only use energy to move the weight of the passengers this method would have a fixed co2 per passenger rate. Once at the top of the side free, readily available and most importantly carbon neural gravity can do the rest. Problem solved for my next trick middle east peace………..

  • Comment number 35.

    I once worked out that whilst running I had a higher carbon emission rate than the lowest car tax band.
    Horses are even worse and should be taxed immediately :-)

  • Comment number 36.

    #34, great idea. You don't even need a tower, any time you want to go up a hill all you need is someone of a similar weight to be coming down the hill to use as a counterweight.

    Admittedly if someone very fat wanted to go up they'd need to wait for several lighter people to counterbalance them, but if getting to your destination faster isn't an incentive to lose weight then what is eh?

    It would certainly make getting to work more fun than standing in the cold on Platform 14 waiting for the 7:47 to finally show up.

  • Comment number 37.

    The statistics on the buses on regular routes is well worth ditching the car. I like Simon Calder's assessment, but I don't think it is practical for long hauls.

    I do take long walks from time to time, in fact, most times. For example, I regularly walk from Pall Mall to King's Cross, which was a habit that started in the January 2007 snow fall. It's something I always suggest to people who want to lose weight as it can be as rewarding as someone who lives in the gym 24/7.

    Justin, if people would stop being too apprehensive, then hitchhiking might start making a lot of difference; perhaps that's from my personal experience, I have never been successful at the game (and I'm good looking). Of course, there will still be abusers of the process but when drivers loosen up their ties a little, they might be generous in making such work or better still the neighbourhood idea that was suggested long time ago, shared driving.

    A lifestyle change decision by most would help the environment. My wife likes to buy eco materials and such stuff, but if she was going 100 metres down the road, she would rather drive (well you can imagine our argument about her eco priorities at home), and most as I've found out do likewise. This is one of the influencing factors for a project I am involved in at Slim 316.

    We need to get on our foot more often, it's good for the environment and very good for the body, too. If you keep fit and healthy, you will eat better food, and better food means better environment because there will be reduced processed foods (which uses a lot of energy to make).

  • Comment number 38.

    I see I am not alone in pointing out the flaw in your argument that, owing to the fact that too few people use the bus, travelling by car is more carbon efficient. With a peak loading, occupants of a bus are travelling at 200mpg - rather better than any other surface transport system including the train.
    It is not the inefficiency of buses that scores them so badly in your simplistic gauge, it is the reticence of commuters to use buses. And has already been said, a bus has the same footprint on the road as three cars, so even at the average loading can make far more efficient use of infrastructure. Or are you areguing that even more of our city spaces is filled with cars, uselessly rusting all day while their owners are at work?

  • Comment number 39.

    Once again, the whole debate is London centric, or at least city centric. We are extremely fortunate in having a well stocked village shop, which I shall be walking to shortly, but I there are very few villages so lucky. Were the shop not open I would be faced with a 5 mile drive to the nearest alternative - many would face far longer journeys. We do have a bus - once a day in each direction, but this simply not practical for going to work - miss it and you are stranded for the night, even if it did run at the right times!

    The city and the country have two diametrically opposed needs for transport, which must be obvious to anyone giving the matter even minimal thought, yet all we ever get from the media is the city/commuters viewpoint. Hence London based pundits get very short shrift hereabouts.

    As for hitch-hiking, well I used to regularly give lifts (yes, to Glastonbury amongst other destinations) until it was pointed out to me that picking up two people who then accuse you of attempted rape will ruin your life, or cost you £50 or whatever, as the person who pointed that out had found to his cost.

  • Comment number 40.

    The most carbon efficient way is not to make the journey at all.

    That's where the analysis about planes being roughly equivalent to cars and buses falls down - planes make it possible, and affordable, to travel regularly to places that we would, until recently, never have dreamed of going. And by creating that option, they cause large amounts of extra carbon to be generated. If the plane wasn't there, most of us wouldn't hop on a bus (or hitchhike) to Thailand for a holiday.

  • Comment number 41.

    Yeh, yeh Justin. But aren't we all just a wee bit fed up with all you boffins prattling on endlessly about carbon footprints all the time?
    Aren't there a few more pressing topics you could direct your super-intelligence towards? Haiti? Our massive national debt? The colossal waste of money that was squandered in Iraq and now in Afghanistan?
    But I forget, you're just humble(?) journalists trying to earn a crust; but actually contributing very little to the real woes of the world.

  • Comment number 42.

    Justin, I have the feeling that your analysis is fundamentally flawed. Is it perhaps that you are answering the wrong questions?

    For example: most car journeys that most people take are to get to and from work. Now if we either worked at home or were compelled to live within a short distance of our work would that not be a far more effective way of reducing the need to travel as far as we do and in consequence reduce our need for fuel! (Recall that it used to be the case the when you started a new job you had, as a condition of getting the job, live fairly near or undertake to move to live near. Are you being sent to Salford?)

    Another example of a flaw: air travel emits its products of combustion at a higher altitude in the atmosphere, than cars etc. and there is I believe evidence that the higher in the atmosphere the products of combustion are emitted the more possible effect on the atmosphere and potentially the weather.

    And of course you are assuming that the emission that you are trying to reduce are in fact those that may effect the atmosphere and possibly the weather. The only combustion products where there is definitive evidence is that of water vapour coming from aircraft - and that is of enhancing global dimming and the emissions of sulphur contaminates are demonstrably a cause of acid rain. The effects of carbon dioxide emissions are unproven and unsubstantiated.

    The best thing to do is to limit consumption through taking steps to limit use, for the good proven reason that unless we do so we will cover the planet with roads (Concrete production is an enormous user of energy) and the we will manufacture more and more cars in which to sit while we wait for the traffic jam to clear (which it won't).

    Justin, please try to think things through a little more logically and ask the right questions!!!

  • Comment number 43.

    I am old enough to have hitchhiked around Europe in my teens, when there was restrictions on Brits getting foreign currency, and hitchiking enabled me to get further for less.
    However I was picked up by drunk drivers had 2 accidents and hit by a vehicle who obviously didn't like hitchhikers. Later in life I travelled around the world and never hitchhiked once. I felt I had had a lucky escape. Its not worth being a green if you end a being a dead green!.

  • Comment number 44.

    When i was a student in the early 90's I used to get the bus home from Colchester to the North East (via London) This journey would take about 8 hourson a good day (over 12hours on one occasion!) so i thought i'd try hitchhiking.

    Igot four lifts. The last lift pulled over in a sportscar and beckoned me over. i thought he wanted directions or something-not really believing someone with such a nice car would want to give a hitchhiker a lift. as it happens he did and was actually going to my town.
    We sped off. and after a brief chat it turned out his work place was in a small village on the outskirts of the town.less than 5 mins from my house!
    it took just under 5 hours for the whole jouney. nearly 300 miles!

  • Comment number 45.

    Care in the Community killed hitch-hiking in the UK.

  • Comment number 46.

    I would have thought that average marginal cost doesn't stack up for public transport in the way that it does for plane journeys. After all, if you:

    1) travel at peak times, you're going to be pretty efficient and carbon-busting anyway, and if they decide to lay on an extra service to cope with demand, it'll still be pretty full and carbon efficient;

    2) travel off-peak, you're unlikely to motivate the train/bus companies to put on an extra service as either way they'll try to run as few services as possible.

    In other words, the pressure to put on extra services only applies in peak times, when you'll be efficient anyway. In both cases, you're responsible for very little carbon.

    Hurrah for public transport!

  • Comment number 47.

    This is a terrible article which propagates bad thinking and harmful myths. It's the sort of thinking which challenges the common wisdom and comes up with some uncommon stupidity.
    I haven't read all the other comments, and I'm sure all the flaws have been picked up on, but here is a summary:
    1) Flying *is* as bad as you might think. Yes the mpg is similar to driving, but the distances are over 100 times greater than a long car journey. So 100 times as much fuel is burnt. If the flight isn't essential, and could be avoided, you're making a big impact on your footprint.
    2) People should not drive instead of walk to help the planet. Not exercising will create far more problems than it will solve.
    3) If people fly less, less planes will fly. Supply is based on demand.
    4) If more people decide to catch busses, the average number of passengers per bus will increase, thus making them more fuel efficient. As you stated, busses are 20% more efficient than cars already, so the bus is always the better option.
    5) Hitch-hiking is clearly not a solution, if everyone decided to do it there wouldn't be enough room. A sensible peice of advice would be car pooling or something. I'm guessing you said hitch-hiking as a joke. This article is a joke but I don't know if it was intentional.
    This article is a force for evil - encouraging and justifying people to do nothing about their lifestyles.

  • Comment number 48.

    It's all very well talking about buses at maximum capacity. But anyone who has ridden such a bus in a large city will know that such travel brings other complications.

    Not least the totally inadequate ventilation during the summer that results in being soaked in sweat (and the resultant need to do more laundry). Or the totally inadequate ventilation during the winter that results in germs and viruses spreading, with the consequent need for pharmaceutical products (and the associated costs of production of those). When the bugs in question are severe (SARS, swine flu etc) this can in turn lead to requirement for medical treatment.

    Cycling is great in theory but the lack of secure cycle parking anywhere renders it risky. I'm not interested in finding out police advice is to take everything with me that might be removed - that basically means I need to take the entire bike, although the trains won't let me take my bike when I need to get to work and the buses won't let me take it at any time. So another link in the joined-up transport theory breaks.

    When anything except private transport inevitably means needing to get to and from the externally decided start and end point of the public transport link the entire system breaks down. Even if a bus ride was free (in terms of both cash and carbon) it's of no use at all unless you can get to and from bus stops, and the bus runs at a time that's useful.

  • Comment number 49.

    ThoughtCrime #48, #32.

    "So my choice of transport is... drum roll maestro... whatever gets me there in the most convenient manner."

    having read your comments (including #30 & #24), I'd say your best choice would be a Hummer with a nice loud stereo, air-conditioned of course.

  • Comment number 50.

    I was wondering, Ethical Man, whether you've had the RUF in any of your calculations? (
    In my opinion it seems quite ingenious, although requiring something like an actual revolution to be rolled out in a manner that would make the principle truly work. The sad thing is that I first came across this concept back in '98 ... and jack'o has happened since. Probably mainly to the fact of requiring something as quite extraordinary as a new transport revolution.

  • Comment number 51.

    Comment 22 Peter Fox. the last person to try to manage the human species didn't get nailed to a cross, he took suicide pills and got cremated outside his bunker as the British approached.
    The scary thing is that just to stabilize population not even to reduce it we would need to kill some 70 million people a year. That's about 100 times bigger than the death camps.
    Nuclear bombs are the only option we have today that actually gets close, but the problem with them is that they're not really the most humane way of killing people. Used in large numbers they're not particularly environmentally friendly either, and they tend to destroy too much infrastructure too. :(

    We can (probably) solve overpopulation without killing anybody just using technology, say by developing industrial scale AB farming. - All it needs is some 10 or 20 trillion pounds. Sigh.
    [end off topic]

  • Comment number 52.

    There is one type of transport that stands out as environmentally very low carbon and that is an electric car recharged from nuclear power. If you want to be pedantic an electric bus would be even better. Of course being a 'futurist' I might like to go one better and have a 50's nuclear car powered directly with its own reactor. :)
    As a few others have said though the best method is not to travel at all - work at home, use the internet. And as for shopping- home deliveries are inevitably more carbon efficient than going yourself.

    As for bicycles, great idea! I wonder how many seconds you can stay on the road on the ice? As a kid I used to bike a mile or so to the school bus every morning and I still remember the brutal cold and the winds and falling off - and wondering if my bike would still be ok when I got back. Bicycles, No thanks!

  • Comment number 53.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • Comment number 54.

    Thanks Justin for such an inspiring blog.
    I´ve found an interesting foundation based in Holland which might help us to offset our carbon emisions, and maybe make feel us better when travelling
    Wonder if someone knows other related sites?.
    From Spain, Eloy

  • Comment number 55.

    I hope that all this has finally reached the point where you understand that without the development of a non-fossil fuel things simply will not improve. The choices presently are to kill the environment slowly or kill the environment rapidly. Seems like we need a different choice. Political reality is that the governments support coal and oil and so change is unlikely until the magnitude of environmental and public health damage is so apparent that it can no longer be denied. The politicans will leap to the stage and declare their support for change and blame the poeple for the problems. This has been the history thus far and seems unlikely to change.

  • Comment number 56.

    Dude, you are made from carbon.

  • Comment number 57.

    Congratulations for discovering the world's most "carbon efficient" form of transport! You also call it the world's most "ethical" form of transport.
    I have a few questions though, that I wonder if you could answer:
    The definition of "ethical" according to the dictionary is right conduct, or right morals. Synonyms are moral, upright, honest, righteous, virtuous and honourable. But to you, to be "carbon efficient" is also to be "ethical". You call yourself the "ethical man", presumably because you strive for "carbon efficiency".
    Would you and others like you still be "ethical" if they strived for "carbon efficiency" yet beat their spouses, were violent, dishonest and swindled other people?
    Would a person who was careless or profligate about his "carbon footprint", yet was gentle and honest, be unethical?
    Does fighting against dishonesty and corruption have a higher, lower or equivalent ethical standard to striving towards lowering your carbon footprint?
    Is lying justified, if you believe that by doing so it will frighten people into action that you believe will save the world?
    I ask this because I was brought up to believe that to be ethical was to be decent and honest. It had nothing to do with your “carbon footprint”.
    In science I was taught to be truthful. When doing experiments to truthfully report the results, not manipulate them to what I thought the answer should be.
    Talking about ethics, what is your opinion on old fashioned ethical values, like honesty?
    What is your opinion on Dr Rajendra Pachauri, who it is reported, supported the bogus claim in the IPCC AR4, that Himalayan glaciers would melt by 2035? That this report was based not on, contrary to IPCC rules, peer reviewed science, but on a journalist’s opinion piece?
    That the IPCC used this “2035 glacier error” to solicit funds for new projects?
    That the EU set up a project to research the ‘rapid retreat’ of glaciers in the Himalayas based on the bogus IPCC report. That EU taxpayers’ money put into this project has gone to TERI, which is run by Dr. Rajendra Pachauri?
    That Pachauri’s own employee at TERI was the source of the bogus glacier claim?
    We are talking ethics here, Ethical Man. What is your opinion on all this?

  • Comment number 58.

  • Comment number 59.

    I hate to tell you Richard but ethics are always relative. In the Christian era rape pillage murder or theft were all considered perfectly ethical if done in the name of the king or mother church, but not attending church regularly would rapidly lead to accusations of heresy then onto a bonfire or torture rack. There are a million examples but the human psyche is totally flexible and all children learn their ethics from the culture around them. (which is why Britain is 'doomed' of course :) )

    Anyway ethical man is called such because it is 'ethical' to try to give the world a better future by trying to follow less environmentally damaging lifestyles. Its a philosophy that might be naive and unlikely to succeed thanks to all those who don't care but it is not amoral.

    Talking of amoral why not look at where most climate deniers get their ideas from, right wing propaganda and lies in newspapers and places like Fox news and the internet. There has been an intense campaign by the American ultra right wing against climate change or global warming or any idea of ecological living. The science is pretty clear but this isnt about science it is politics. A lot of ecological policy originally came from liberals and the left, so it is just natural instinct that the right come to attack it. Their campaigns have made the transition to things like lower carbon technology far more difficult and this has all been deliberate. Behind everything is the old philosophy of valuing the dollar bill above anything - and not caring about anything else.

    There is nothing illogical about the idea of Himalayan glaciers melting, it is just the date that is probably exaggerated.

    Incidentally this recent cold snap was driven by cold air escaping from the arctic region and overall represents an increase in the rate of change by increasing air temperatures in the polar region. Instability in these winds could mean we have frozen summers and boiling winters, and above all unpredictability. Even with the cold, last year was still one of the ten hottest on record. (New Scientist)

  • Comment number 60.

    Robert Lucien wrote: I hate to tell you Richard but ethics are always relative.

    Relative? Are you saying that it is ethical to lie?

    You say “The science is pretty clear but this isnt about science it is politics”. (Presumably you are talking about the science of Anthropogenic Global Warming). And then you say “There is nothing illogical about the idea of Himalayan glaciers melting, it is just the date that is probably exaggerated.”

    Have you the foggiest idea about Science? Leave alone “The science” (of Anthropogenic Global Warming I presume).

    There is nothing illogical about the idea that a 10 Kilo cannon ball will fall 10 times faster than 1 Kilo cannon ball. In fact, that they fall at exactly the same rate is pretty illogical.

    A logical idea is a hypothesis. Science tests hypotheses. Galileo was the father of the scientific method. He tested that hypothesis by dropping the cannon balls from the Leaning Tower of Pisa. The hypothesis, (held true as a theory for 2 thousand years, since the time of Plato), came crashing down when the two cannon balls crashed to the ground at the same time. He didn’t have an explanation for it, that came a generation later when Isaac Newton formulated the theory of Gravity. But what he did establish was that the theory was wrong.

    Exactly such a hypothesis is Anthropogenic Global Warming or AGW. A theory is tested by its predictions, not by its logic. Measurement and calibration are at the root of scientific experiments that test hypotheses.

    So when you say “There is nothing illogical about the idea of Himalayan glaciers melting, it is just the date that is probably exaggerated.” You are partly correct. It is logical because Himalayan Glaciers have been retreating for 150 years, long before any alleged effect of AGW. But the Glaciers have shown no increase in their retreat. The maximum amount is about 2-3 feet per year, most far lower. Taking even a maximum rate of 1m per year the Gangotri glacier, for example, which is 30 kms long, would take 30,000 years to disappear. Long before that we will be in our next ice-age.

    No sir, there will be glaciers in the Himalayas in 2035. The IPCC has been forced to admit it now, though you maybe loath to.

    Coming back to ethics, I am not saying Ethical Man is not ethical. I would bet my bottom dollar he is, just that he is mistaken and duped, as you are. It is precisely because I believe he is ethical that I am asking him, and you, is it ethical that a person spreads a falsehood and a lie and profits from it off the taxes that honest people pay?

    Why do I get no answer?

  • Comment number 61.

    I think the point with global warming is that if the theory is wrong and we prepare it won't be a huge disaster, however if it is correct and we do nothing we are facing a catastrophe. Even without climate change humans are still pushing the global ecology towards its limits. - Rising wealth in the third world, rising population, huge low grade industrialization in the developing world, etc, etc.

    As for the science I'm a regular reader of New Scientist and other science media and have to say that the general opinion is pretty much overwhelmingly in favour of GW. I generally believe in Gaia theory and if that is correct then the situation is probably actually a lot worse than most are predicting.
    I admit I am not a GW specialist, I am a General Scientist specializing in Strong AI, computing science, relativistic physics and futuristic prediction (for science fiction). I also have a long interest in ecology and green issues and things like genetics so I do understand a lot of the issues.

    I actually do agree with the anti global warming people on some things, a lot of what we are doing now is futile and a waste of resources, if GW is real its probably already unstoppable and the solution should be to deal with the consequences. My own 'science fiction' solution is a cheaper one at only 20 trillion, but it would have a massive payoff in new technology and probably pay for itself before it was complete.

  • Comment number 62.

    Robert Lucien wrote: I think the point with global warming is that if the theory is wrong and we prepare it won't be a huge disaster, however if it is correct and we do nothing we are facing a catastrophe.

    Actually exactly the opposite. An insurance policy only makes sense if the premium is less than the principal being insured. What we are “doing about it” is already a disaster and if we continue we face certain catastrophe. Our economies are rapidly going downhill. The unemployment rates and National Debts in the US and Europe are climbing rapidly. Unless we stop this madness and be sensible, like China and India, we will wind up like the Weimar Republic of Germany or Zimbabwe, where a wheel barrowful of money wont buy you a loaf of bread.

    Even without climate change humans are still pushing the global ecology towards its limits. - Rising wealth in the third world, rising population, huge low grade industrialization in the developing world, etc, etc.

    If you want to do something about the ecology, great. Spend money on clean water and sanitation in third world countries, generation of power from coal, with technology to reduce real pollution, Lead, Mercury, SO2 and Nitrous oxides. Not CO2, which is plant food, as any horticulturist knows, so depleted in our atmosphere that they pump it into their greenhouses to make plants grow better.

    Power is urgently needed to power their farms, factories, cities and houses, (as ours), and give them a better quality of life. The best way to reduce population is to educate and emancipate women.

    Instead we spend money on trying to reduce CO2 and believe that all good, such as control of pollution, will follow as a knock-on effect of this. Spending money on reducing or sequestering CO2 is a total waste of money and resources. Isn’t waste unethical? Isn’t that what Ethical Man is all about?

    We have spent over 60 Billion US dollars on Global Warming research. An industry that only exists because it perpetuates the myth it is supposed to fairly and dispassionately research. There is a conflict of interest. Would you place much faith in a drug that has been researched by a person who also stands to gain a lot by its sale?

    The Himalayan Glacier scare is typical of this industry. One sixth of humanity depend on the waters from those glaciers. If they disappeared anytime soon that would be a catastrophe. So out comes this “report”, that a prominent Glaciologist said was so ridiculous it wasn’t worth refuting, and taxpayer money is poured into research to try and mitigate the effects of this alleged “catastrophe”.

    You and Ethical Man still haven’t given your opinion on this.

    If you are a reader of New Scientist, listen to what its former editor has to say about it, or the co-founder of the Greenpeace.

  • Comment number 63.

    Here is another view about the "precautionary principle", invoked by Robert Lucien. This also reveals a moral issue.

    Ethical Man would you care to comment on this moral issue?

  • Comment number 64.

    You asked for hitch-hiking stories. A carpooling system that works in the USA is sometimes referred to as organised hitch-hiking. Informal flexible carpooling is a system that gives rides to thousands of people every day. Yes, thousands. I estimate that it saves lots of energy, emissions, time, etc. Here is a blog by a person who uses it every day: . The informal systems are called slug lines, and casual carpooling. We are also promoting a formal version that captures the same central idea. You could search on 'flexible carpooling' to find out more.


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