I'll probably end up in the spam-blocker for posting several links, but the driving vs. walking comparison has been made and criticized before. See:

http://www.stat.columbia.edu/~cook/movabletype/archives/2008/03/the_all_else_eq.html

and

http://www.treehugger.com/files/2007/08/ask_the_ecogeek_6.php

with some of the key points being that people who drive, drive farther than people who walk, walk, and that if one considers all carbon wasted in our inefficient food supply system, it's certainly discouraging, but if one compares it to the carbon cost of creating and maintaining a car, the latter ends up the larger environmental loser.

I may be missing something (math makes me nervous and I might have blacked out during the presentation), but who said that bikers eat more than drivers? Assuming american bikers and american drivers eat the same 2700 cal pile o food, how is it you only add it to the biker's spreadsheet?

Even in Oz it's not good, although we haven't yet achieved the true hideousness of the US food chain. So our food costs are lower but still obscene (total cost, not dollar cost).

The one thing you slid past was the vegetarian option - if a higher meat component pushes the cost up, lowering it pushes the cost down. For the most part, anyway - me eating roadkill when I'm cycle touring is probably fairly neutral, in that few people farm animals specifically to make them into roadkill, but a lot of native animals become roadkill.

Also, talk to us about packaging, Brad, that's another exciting area of "just how dumb are we, really?"

And finally, have you looked at scanning/OCR recently? I've bought a Sony PRS-505 (my first ever Sony {hoik spit} product), and I'm struggling to find some books online, so I'm using my 30D and a sheet of glass to scan books and OCR them. Slow, but beats paying another $2000 for a decent sheet-feed scanner and cutting the spines off my books. There's got to be a better way...

"We eat, on average about 2700 Calories/day in the USA"

OINK!

A similar argument, on a slightly different topic, is made about ebikes by Justin Lemire-Elmore on ebikes dot ca.

http://www.ebikes.ca/sustainability/Ebike_Energy.pdf

Brad, you make a good point about agriculture's high consumption of fossil fuels, but it is absurd and misleading to say that walking or riding a bicycle consumes significant amounts of fossil fuel (e.g., two people riding bicycles consume more fossil fuel than two people in a Prius). Perhaps your calculations on walking and cycling are intended tongue-in-cheek. In one of your responses you acknowledge that if you exercise anyway, on a stationary bike, you use the same amount of food energy (it's worse if you drive to the fitness center or if you run on an electric-powered treadmill). So for the person who would do some other exercise if not bicycling for transportation, the bicycle trips are really free: zero gallons per mile (miles per gallon approaching infinity).

For the person who would not exercise much if not bicycling for transportation, the trips are also essentially free. You dismiss dave's comment too easily. You seem to believe that the exercising person really does consume more food, and therefore fossil fuel, than the non-exercising person. You have neglected the fact that there is a lot of waste at our end of the food production-preparation-consumption-utilization chain: We eat more food than we use and we buy more food than we eat. (The unused energy from the food we eat either gets converted into fat stores or goes literally down the toilet.) You have to show that the person who exercises actually buys more food than the person who does not, which I doubt very much is the case. And even if we allow, for the sake of argument, that the person who travels an hour per day by bicycle actually does eat a little bit more, the extra food could be completely carbs (pasta, pancakes,...). That would change your calculations, which assume the extra food is in proportional amounts of the average American diet, which includes a lot of meat.

If you want to do something useful with calculations, why not show us how many gallons of gasoline we could save per year by making various kinds of choices: vegetarian diets vs. eating meat (various animals), buying food grown close to home vs. food that is imported (can we save gasoline by importing certain foods from places where less fossil fuel is used in agriculture?), living close to where we work vs. living far away, and of course various means of transportation vs. driving alone in a car? For starters, I estimate that I saved about 100 gallons of gas per year when I bicycled to my job, which was five miles from home (compared to driving my car, which gets about 25 mpg in the city).

I think people are missing your point because you buried it. If you want to make a point about embodied energy of agribusiness food, make it; don't talk about biking or walking versus driving.

I did a similar analysis and got:
Riding 6 MPH on a local organic diet gets around 2500 Miles per Gallon (of fossil fuel).
Riding 14 MPH on that diet gives around 679 Miles per Gallon.
Riding 6 MPH on an American diet gives around 250 Miles per Gallon.
Finally, riding 14 MPH on that diet gives around 67 Miles per Gallon (not much better than a prius).

I also hereby claim that an American who bikes (say 5 miles) to work every day is eating less than one who drives that same five miles. All else being equal.

Thank you kindly.

I'd be curious to see where an electric bicycle would fit in here. A typical electric bicycle will weigh about 50 lbs and provide 360 Wh of energy to help propel a bicyclist. I would expect much better results per mile than a regular cyclist since you're replacing that much energy that a human would've generated with 3 cents worth of electricity. But it may be pretty close compared to an electric scooter. An electric bicycle would only travel at regular bicycle speeds and would not have to overcome all the higher wind drag an electric scooter would experience. It would be lighter as well.

I guess I'd be curious to see numbers where the bicyclist is not pedalling vs moderate pedalling (providing half of the total energy).

I understand your point, and yes, petroluem driven agriculture is incredibly inefficient, and there's far too much beef in American diets. Those points stand.

However, there is one part of this comparison that's not fair, and has been brought up in other criticisms of this argument. If you're going to calculate in the energy required to raise the "fuel" for the human body, you have to do the same for the gasoline. My guess is that your point would still stand, but that's a fair criticism. You can't just pretend that the gasoline came from nowhere.

My observation is that the average American cyclist is thinner than the average American. It may be that the transportaton is fossil fuel free or even better than that.

Have you consider how many calories are burnt by a human while driving the car? That is surely more than what is burnt by just sitting around?
So while calculating the mpg for a car, you should also count the extra calories burnt by the driver!

For all the cheerleaders who insist that the numbers must be wrong because bycyclists eat less than the "average" American, or they would be exercising anyway (thus making the exercise of bicycling irrelevant to the overall petroleum footprint), you seem to be missing a HUGE point.

Unless and until the average Joe Sixpack begins bycycling on a regular basis to REPLACE his current driving habits, the overall impact on national fuel consumption is minimal.

Once Joe Sixpack IS cycling instead of driving short distances, that doesn;t IN AND OF ITSELF, change any of his OTHER habits -- thus the extra metabolic energy consumed in cycling versus just sitting in a car driving the same trip IS an additional energy consumption. So, comparing the total petroleum cost of the food to produce that extra energy (including teh cost to get it from the market through the kitchen and down his gullet) is going to count. When Joe SIxpack feels hungry after biking 10 miles instead of driving, he's going to get a sugar and cream laden coffee to wash down his sticky buns and sausage McMuffin.

The asusmption that Joe Sixpack will magically transform his lifestyle into one that is typical for bycycling commuters is insanely naive. He is still going to be the same beer-swilling, pizza devouring, hamburger grilling (on a propane grill or worse yet and electric stove, no doubt) pig he is ALREADY. And he's going to offset his additional metabolic exercise with teh same type of high-petroleum impact crap he already eats when he gets bored.

People who bycycle commute are ALREADY predisposed and more likely to have lower total footprints in other ways -- they tend to eat healthier, wastefully consume less, and would be burning off those calories ANYWAY. But the bicycle doesn't magically transform them -- you've confused correlation with causation. They bicycle (in large part), becuase they are the type of people to do such inherently greener activities. . . bicycling doesn't make them so.

If you were made Emperor of America, and you waved your wand and made all cars simply not work for short range commuting, that effect will not turn Joe Sixpack into a lean, mean, recycling machine, just because he huffs and puffs his way to work on a bike each day.

This is quite interesting. We are certainly going to have to learn to be thorough in energy accounting if we are to understand our fuel and climate problems.

I have another point to add: In cool climates (like the netherlands, germany, scandinavia where biking is popular), or in winter, the person driving the car will travel in an environment close to his/her body temperature (car heating). This heat is waste heat from the engine and costs nothing 'extra'. However, as our bodies seek to maintain the same core temperature in any ambient temperature, we will lose more energy when the difference between outside and body temperature is greater, as when riding a bike. Research seems to support this idea: http://www.nature.com/ejcn/journal/v56/n4/full/1601308a.html

So spending an hour or two riding a bike in cold or rainy weather could significantly increase energy needs. This, and the idea that the cyclist will eat more, is supported by everyday experience: a desk-worker who spends a day out in the cold or doing hard physical work will often notice that s/he is much more hungry at the end of the day than usual.

I have also wondered if higher indoor temperatures contribute to obesity - I have noticed that in some countries where consistently lower indoor winter temperatures are tolerated, people are thinner, sometimes despite a heavy diet. This (small?) difference could tip the equilibrium of energy consumption over several months or years.

but how much energy does it take to refine and transport the fossil fuels everyjthing seems to use and abuse?

I'm just curious as to where you sourced the information about how much fossil fuels are spent in the production and shipping of agricultural produce. I'm not questioning your conclusion. I'd just like to see if there is also available data for Asians also, just to see how it compares - since South Asian agriculture seems to use more human labour.

OMG people! You're beating the details to death and it's nothing but mental masturbation. And you're not going to be any more satisfied by this nit-picking either.

The point that using the least energy to achieve any task is not always obvious, but not even readily determinable, is made and clearly so. Let it go. Grasp the point made, and make your choices. Don't argue the details.

Will the world's use of energy change one iota if you make via your discussion even a 40% correction to the numbers used? No. Will YOU drive to work instead of walk, or the other way 'round, depending on the numbers? I doubt it. Our average commute in this country is just too far to walk, so you won't, no matter how much less energy it uses.

Now, why don't some of you geniuses apply your turgid grey matter to convincing the world's population that they should give a crap? THAT task would be worth all the mental energy you're putting out. One of you might think eventually think of something that's, well, genius!

Brad, if you read the article you cite it is clear that the actual fossil fuel intensity of agricultural styles varies significantly from society to society. The authors of that paper make the point that North American/Australian agricultural systems produce 1 to 2 times as much energy in food as is consumed as fossil fuels in its production (ie; it is efficient) whereas in most European agricultural systems, and in Japan, the system is highly inefficient with multiples of input fuel energies over output energies of food energy - in other words, ineffienct. While African agronomy is fossil fuel efficient (30:1 food energy output vs fossil fuel inputs) this is relatively speaking not very land-efficient nor efficient for human capital. ie; one would have to argue that human labor in the food chain in low-technology countries replaces fossil fuel energies significantly.

The fact is also that, whilst beef production in America is done on cereal feeds in feedlots and is inherently inefficient, the American vegetarian is actually more fossil fuel efficient than the Chinese average person because American fertiliser is coined from natural gas and Chinese from coal. So one can argue that the most ethical and environmental choice is to become an American citizen and eat a non-organic American vegetarian diet (given that organic farms are less energy efficient than non-organic broadacre commercial farms).

Going down this route, you can reduce your fossil fuel intensity per calorie to as little as a sixth of a Japanese person, and perhaps half of a Chinese person. That tends to throw a spanner in the works. Indeed, one thing this analysis tends to conclude is that the best way for American people to reduce envirnmental impacts of fossil fuel utilisation in agriculture is to, in fact, subsidise and encourage Chinese uptake of natural gas nitrogenation as opposed to using coal. This efficiency alone would reduce carbon impact and input energy intensity dramatically.

I'm writing an article about the behind-the-scenes energy costs of cycling versus riding a moped. I know that each Calorie of food takes about 10 Calories of gasoline to produce/deliver/store, but how many Calories of gasoline does it take to produce/deliver/store a Calorie of gas? that's the final figure I need for my article-- thanks so much!

Fascinating analysis. As a cyclist, every instinct in me is to take your analysis apart and I see several people have tried and mostly failed. I gave up until I thought of this. What is the fuel to wheels energy cost in a gallon of gas? Surely just as food takes a lot of energy to produce and transport, so does gasoline. Are you comparing apples to oranges when you measure the energy content of extra food calories based on the physical energy content of a gallon of gas? Don't you have to compare to the energy content of the gallon of gas plus the energy it takes to produce and deliver that gas to the consumer?

I would also add that as cyclists are slimmer on average than the general population that cyclists do not replace every extra calorie burned with one more eaten. Slimmer people burn fewer calories at rest so if cycling does in fact contribute to maintaining lower body weight then the net calorie consumed as a result of cycling could be much lower than your assumptions even negative.

You seem to assume that we realize all the calories we get from the agribusiness, but a lot (more than 50% according to some UK sources) is wasted (so most of it ends up in landfill producing CH4, and needs more energy to be refrigerated/waste-managed).

It is my impression, but a serious study should be conducted, that walkers and cyclists tend to finish-up what's on their dishes, while drivers are more prone to "waste" it. Also, driving to large supermarkets make people overshop, for carrying is not a problem; and overshopping is one of the primary reasons behind excessive domestic waste (in the UK alone, each day 5000 chickens are thrown in the bins for being past their sell-by date).

So how much fuel am I using when I cycle up to 350 miles a week, on average I am doing around 200 miles a week at around 19mph average.

Probably eating around 2500 calories a day.

Another few points to consider about bike riding:

they have 1 extra shower a day
they wash 1 extra load in the washing machine a week.

So factor the energy used to heat the water as well as for the washing machine.

I'd say I'd have to agree with this article that your calculation mostly just functions for shock value, not because it in any way takes fully accounting of the energy used in each activity. You've taken a single snapshot of driving a car today so you can then nicely skew your results by only comparing the fuel that the car consumes to the *entire* process of raising beef: including the fossil fuels to provide the fertilizer; to run the tractors, to process and transport and refrigerate the food and to grow the food that the cows eat. Then you wave your hands and explain away why you don't need to take account any process that is required to get the car there. In this way you can rig the contest so driving always wins out over walking.

The cars and the infrastructure in which to drive them don't just appear out of thin air. They require mining raw materials, factories, labour, highways and roads, road widening, parking lots, filling stations and so on. None of this is included in your calculation.

To make it easier to avoid the embedded energy of the car you restrict your calculations based on a subset of humanity: those Americans adults that already own cars. Yes, if you rig the calculations this way you can avoid the messiness of reality. And by only including a small window of time for the car traveling you can avoid the messiness of calculating the energy requirements of providing the entire asphalt/concrete/landscaping infrastructure in order that the car can actually be there.

If someone chooses to walk, bike or take transit it means one less car and means that much less requirement for wider roads, freeways and parking lots. One can easily imagine this impact when one imagines what a place like New York City would be like if *everyone* decided to get from point A to B by automobile instead of by walking, biking or transit. From an estimate I saw some place, we could imagine the entire island of Manhattan being dedicated to roads and parking with nothing left for the actual buildings let alone parks or sidewalks. Currently only about 50% of NYC adults own cars and thank god for that (China is at 13%, Brazil at 15%, India at 1%! - http://en.wikipedia.org/wiki/List_of_countries_by_vehicles_per_capita). If they moved up to about the 95% car ownership rate of adult Americans you'd have to include the estimated energy costs of doubling (more or less) the entire NYC network of roads and parking lots. That's a huge amount of energy. Now imagine if the rest of the world moved up to America's car ownership level so they can have the option of taking the car to the corner store. Wow. Massive.

Unless you adjust your calculations to the *full picture*, you are hardly participating in "transportation energy economics" or "full cost analysis", but merely an exercise in convenient rhetoric.

There is no escape to consuming gasoline. Let's just take this one person at a time. Let's just do our part and walk if we don't really need to ride, maybe grow some of our food, try to eat less,etc.

I have yet to see the calories behind producing gasoline in this thread. I mean we are making a big deal of the embodied energy in food but not into the exploration, extraction, and development of the fuel for the cars. This is a one sided argument that fails to consider the variables for both sides in order to make it an equal camparison.

Hi Brad,

Great post. And you're the first Templeton I've ever met outside my immediate family, so hello.

First of all, everything you say makes total sense to me - nothing wrong with any of the figures or anything in your argument.

This blog is very interesting in showing us that perhaps a 10 mile return commute by foot fuelled by our industrial agricultural systems would be similarly impactful as driving that commute.

Can I just add an extra dimension to the analysis which I think people may find useful in extending the comparison of different modes of transport.

An absolutely fundamental thing about particularly air travel but also car travel, when compared with something like walking or cycling is just how easy it is to do extraordinary amounts of mileage.

This is of course crucial to the 'actual' impact, which is calculated as - (damage per mile) x (miles travelled).

So while I may cycle 10 miles to work and back tomorrow, it is harder to imagine me cycling 5,000 miles tomorrow. Yet if I was restless and I wanted to I could get on an aeroplane and travel 5,400 miles from London to San Francisco in about 18 hours straight.

And if I was the kind of person who drove to work, I think I'd be a lot more likely to move house to somewhere 50 miles from my workplace to save a bit of rent and enjoy the countryside, than if it would mean I had to cycle 100 miles per day!

A thought experiment for you, or if you want (as I have) you can make it a real life process: "How would the choices I make over where I live and what I do change if I decided not to drive a car or use air travel?"

My prediction? You'll cut at least 50% off the miles you travel. Probably more like 80%.

Now that's what I call global cooling!

Matt Templeton

While I find it very interesting how much fuel it costs to grow food, this is a pointless argument, because nobody purposefully eats less (or more) because they will be driving, therefore driving costs more Calories.

If eat 2700 worth of calories for the day and it costs 300 Calories of fuel to drive to the supermarket, it costs me a total of 2700 Calories to walk, and 3000 to drive.

What's required to use the car is for me to offset my own calories, and only eat 2400 Calories that day. Using transport needs people to change their diet, but your article doesn't state this.

Nice set of calculations you got there, but there's 2 minor assumption flaws:
1. People don't automatically eat more when they walk
2. Most people trying to reduce their weight, don't burn anywhere near the commonly accepted burn rates (due to a reduced metabolism). People's body chemistry actually changes when they get below a certain obesity level.

1. The calorie is a measure of energy based on the heat required to increase the temperature of water.
Exploding something underwater and measuring the subsequent temperature change of the water is not in any way analogous to the human digestive system. We have no idea how much energy people extract from foods, nor do we have much of an idea about how much energy people expend for various activities.

2. This analysis assumes that people replace the number of calories they expended walking/cycling. The vast majority of Homo sapiens have large amounts of stored energy to expend.

3. This analysis assumes that agriculture need rely on fossil fuels. Eat local and organic. I ate a bunch of beans today for lunch, probably about 200 kcal worth. I grew them in my backyard without chemical fertilizers or other petrol-based products. It is not difficult to feed oneself without petrol.

4. Does this analysis consider the insane energy costs associated with all of the labor and machinery involved in finding, extracting, processing, and shipping oil? How about the energy costs of building the car and sourcing its materials? The machines used to drill for oil probably run on oil, and the workers operating the machines are probably eating petrol-intensive factory farmed animal products.

5. The author is correct to elucidate how unsustainable and petrol-dependent factory farming is. However, even the most subtle implication that walking may be comparable to driving in energy cost is scientifically irresponsible and epistemologically absurd.

I really like this post, and have referred to it a few times these past years to

We see more and more of "green" logistics stories such as this one: http://www.theguardian.com/environment/bike-blog/2015/jun/10/why-cargo-bike-deliveries-are-taking-over-the-uks-cities

If I interpret your post well, it might not be so green after all considering that a professional cyclist carrying heavy loads all day long will require much bigger Calories intake to perform well.

I work in Urban Logistics and we know for a fact that a key component to reduce the footprint (both congestion and carbon emissions) of goods transportation is massification. It is indeed much better in all accounts to supply a downtown supermarket with one single 20t truck every other day than with a fleet of 3.5t trucks (900kg of useful load) that come and go 3 times a day. It is also much better to have a downtown large supermarket where people walk to to perform their purchases, than a suburb mall where everyone drives to to get their weekly groceries. That would seem to condemn fleets of small loads on bicycles to perform the logistics tasks that a city needs to live (according to a french survey, 35% of movements are with the intent to move a good rather than a person).

Any thoughts on how you robocar project might help with urban logistics?

Great article! I had no idea tomatoes were used to save all those people!

WE....... are RUNNING out of GRAVITY. Have You heard of GRAVITYY? IF not YOU're taking ADVANTAGE OF IT. I noticed this ONE DAY when I was Running. I started breathing heavier AND ran FASTER AND FASTER than I ever HAve BEFORE. THen I relized WE ARE running OUT of GRAvity. I would LIke to THANK MICHAEL from V-sauce. I love you.

The MPG numbers for car and energy used to produce food take into consideration the efficiency of the vehicle or process. But, you assume 100% human efficiency in that the human only has to replace the exact number of extra Calories required to propel himself over a distance. I believe human efficiency is about 25% so I would expect you'd need to consume 4x the number of extra Calories required to propel you.