Climate Change

Drive, Don't Walk


An addendum of sorts to Katherine's post below on surprising energy-efficiency conclusions when it comes to "growing local": it could be that walking generates more carbon than driving-at least if beef (or milk) is what's for dinner. How so?

Food production is now so energy-intensive that more carbon is emitted providing a person with enough calories to walk to the shops than a car would emit over the same distance. The climate could benefit if people avoided exercise, ate less and became couch potatoes. Provided, of course, they remembered to switch off the TV rather than leaving it on standby.

The sums were done by Chris Goodall, campaigning author of How to Live a Low-Carbon Life, based on the greenhouse gases created by intensive beef production. "Driving a typical UK car for 3 miles [4.8km] adds about 0.9 kg [2lb] of CO2 to the atmosphere," he said, a calculation based on the Government's official fuel emission figures. "If you walked instead, it would use about 180 calories. You'd need about 100g of beef to replace those calories, resulting in 3.6kg of emissions, or four times as much as driving.

What if, instead of beef, the walker drank a glass of milk? The average person would need to drink 420ml – three quarters of a pint – to recover the calories used in the walk. Modern dairy farming emits the equivalent of 1.2kg of CO2 to produce the milk, still more pollution than the car journey.

Chris Goodall's personal site with more low-carbon life info.

NEXT: Like (Energy-Efficient) Lambs to the Slaughter

Climate Change

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49 responses to “Drive, Don't Walk

  1. well, nice, but this will also just turn into red meat (arg) for the vegans who think if we all ate nothing but soy chips the world would achieve nirvana

  2. It’s not clear that Goodall included the externalities for the driving.

  3. I’m not sure if I buy this reasoning, it sounds suspiciously like the “Hummers use less energy than hybrids” argument.

  4. Yeah, it could very well be true, but I’d be happier if another expert in the field ran the numbers as well. It sounds fishy. And it sounds like the sort of calculation where you could easily wind up counting something on one side of the equation but leave out the counterpart on the other side of the equation.

  5. This is pretty lame. Does the author show that people who typically walk to the market eat more than people who drive?

    Plus, a mile and half (3 miles round trip), is kind of a long way to walk just to go the market. I don’t know anyone who walks that far, unless they’re stopping on the way home from the train or something, in which case, they aren’t doing any extra walking.

  6. Speaking of externalities, how much carbon will extra hospitals for the morbidly obese produce? Those math people never think of the contingencies.

  7. I don’t have any trouble buying this reasoning.

    Maybe that’s because environmentalists have been thinking in terms of products’ entire lifecycle for some time.

  8. Whoops, I thought this was the other thread.

    This reasoning is among the dumbest thing I have ever read in my entire life.

  9. once again the problem boils down to people. As in we need less of them.

    Anyone for a little environmentally friendyl genocide?

  10. And they didn’t factor in road rage, which is the calorie-burning equivalent of a 1/2 round of boxing in the movies.

  11. Maybe you’re right, joe. But I’d still like it if somebody else ran the numbers.

    As was pointed out, people who walk to the market might be doing so on their way from another errand anyway. Or they might be doing so as a substitute for some other exercise activity. If I spend less time at the gym but walk to the store to compensate, I personally burn the same amount of food as I would have if I’d driven to the gym and store, but I don’t burn the same amount of gasoline.

    Once you start looking at the ways in which activities are substituted, it becomes a lot more complex.

    Plus, given the variability of fuel use in the production of different foods, I’m not sure how useful these numbers are.

    Again, if the numbers are right then the numbers are right, but it smells fishy, so I’d like to hear another expert weigh in.

  12. I’ve seen better flakes in my cereal than what this author is suggesting.

    Hey, here’s a novel idea: how about coming up with an eco-nut book that chastises our lazy industrialized society without putting us in a damned-if-you-do-damned-if-you-do-not situation? The kind of horsecrap coming from this Brit bloke actually leads people to just do NOTHING because no matter what they do, the planet is screwed anyway.

  13. Yeah, this study is bogus, unless the average person eats a diet entirely of beef.

    They’re choosing one of the most carbon-intensive segments of the food production industry to compare. (Notice how the amount of carbon dropped by a factor of 3 when they switched to milk, still a high-carbon segment). Most people’s calorie consumption comes mostly from carbohydrates, so the carbon footprint of wheat or corn would be a more appropriate thing to compare.

  14. Yeah, unless you are on phase I of the Atkins diet the rest of your live, this argument is bull. Walking, if you live in a pedestrian-friendly neighborhood, is better for you and better for the environment.

  15. Uh, keep in mind, any time you’re getting food from a domesticated animal, you’re going to have to include the carbon produced by the animal itself plus the carbon produced in growing vegetation for the animal to consume. So it can’t help be much less efficient than just consuming the grown food directly.

  16. Externalities, models…leading to a simple headline-like conclusion.

    When even personal carbon calculus gets this complex, it seems difficult to expect a global model of climate to provide results for anything but rudimentary, directional outputs.

    If models could simulate real systems, with full fidelity, in real time, well, then would it be a model or the thing modelled?

  17. So, if Shikha Dalmia drives a Hummer to buy lamb from New Zealand….

    And cooks it on a gas stove…

    But walks to a potluck…

    At the house of an oil executive…

    But gets too drunk to walk…

    From organic wine…

    So she gets a ride home from a designated driver…

    Who drives a hybrid….

    Does anybody care?

  18. I just RTFA, and wow, the person writing that piece is either a fool or a shill. They contend that Goodall is “shattering environmental myths” with his book. Apparently he’s also discovered that trees are not as good for combatting global warming as was previously thought, since they emit methane. (??)

    Of course, anytime someone claims to be shattering myths about something common-sensical, hold on to your wallet.

  19. If models could simulate real systems, with full fidelity, in real time, well, then would it be a model or the thong modelled?

  20. If you only eat meat from animals that browse fields for their foods, rather than those given feed, you can eliminate a great deal of the carbon footprint of your meat.

  21. LowCarbonLife is riddled with junk science. The claim “The energy used to provide the food on our tables is about nine times greater than the calorific value of the food itself” comes from Pimental, completely discredited environmentalist. He made the outragous claim that 1600lb beef cattle consumes 1 ton of crude oil to produce, among others.

  22. I like how the author uses the carbon cost of the entire creation process of the food, but only the CO2 created by burning the gasoline. Obviously, there is no CO2 created when oil is pumped from the ground, transported to a refinery, refined and then transported to the gas station. All the CO2 comes when the gasoline is used. Bravo to Goodall for having the courage to speak truth to the power that is Big Walking.

  23. (disclaimer: I don’t know how true any of this is…take it for what it’s worth)…

    From this site…

    Benefits of cycling:

    How efficient is Bicycling? Here is an egg-planation.

    A bicyclist burns about 25 Calories per mile. One large egg supplies 80 Calories. A cyclist can travel about three miles on the energy of one egg.
    0 (symbol for one egg)

    A person walking would require three eggs to go the same distance.

    A loaded bus requires the equivalent of two dozen eggs for each person it carries three miles.

    A train requires the equivalent of three dozen eggs for each person it carries three miles.

    A car that gets 12.5 miles per gallon requires the equivalent of seven dozen eggs to carry one person three miles.

    Even if you double the miles per gallon and double the occupancy a car will still use the equivalent of twenty-one eggs to make the trip — more than twenty times a bicycle.

  24. Mo-

    This is why I’m deeply skeptical of life cycle analysis. In principle, it’s the right way to approach environmental issues. In practice, it probably makes more sense for people at each stage of the process to simply ask themselves “How can we minimize energy use in this process?” and transmit that information via pricing.

    If I pay the energy bill, I worry about the energy involved. Otherwise, I could tie my brain in knots worrying about whether the light bulbs in the theater should be averaged among the occupants, or whether I should only consider the marginal impact of adding one more occupant, and how this compares to the light bulbs at my apartment and the energy to run my DVD player.

    And don’t even get me started on driving to buy the microwave popcorn vs. the heat lamps over the theater popcorn.

  25. jimmydageek, that’s an analysis of calories from the egg as an energy source, which is a different consideration than net CO2 output.

    You’d need to determine the CO2 footprint of the egg to equate that to the car/bus etc.

    Still the bike-to-walking ratio is entertaining in and of itself.

  26. Why was this posted without the appropriate sacrastic dismissal of it as junk science?

    I can see posting it with a “Look at this idiot” tag, but how do you post something this flawed with a “it could be that walking generates more carbon than driving-at least if beef (or milk) is what’s for dinner. How so?”

    Or is Mr. D, just too deadpan for me to get it?

  27. Yea, just posted strictly for entertainment value 🙂

  28. Isn’t all this BS what prices are for?

  29. A person walking would require three eggs to go the same distance.

    More like 5, ain’t it?

    You’d need to determine the CO2 footprint of the egg to equate that to the car/bus etc.

    Don’t forget to put calculate the carbon footprint of manufacturing the bike compared to bus/car.

  30. c-a-j,
    No prices measure cost, utility and supply and demand. Energy only comes about in the cost portion of that. Unless you think a lawyer at a top law firm uses significantly more energy than a lawyer at a middle of the road firm.

  31. So, the moral of this story, is if you MUST feed the trolls, feed them low-carbon-footprint lamb, not just low-food-mile lamb. Think this stuff through, people!

  32. The other moral is, check what thread you’re actually posting in before posting. Your lame jokes are then slightly less baffling.

  33. Even taking science as true (which I highly doubt), this is complete B.S. Most people who would choose to walk rather than drive are more likely to be more health-conscience, and, in turn, eat less red meat. In addition, just because someone hasn’t used more energy because they drive, are lazy, etc., doesn’t necessarily mean that he or she will eat less red meat.

  34. I’m still trying to figure out “paper or plastic” . . .

  35. So how bad for the environment is it when I’m getting it on with the ladies?

  36. Taktix? | August 6, 2007, 3:24pm | #

    So how bad for the environment is it when I’m getting it on with the ladies?

    Depends on the amount of Crisco? you put between you and the “ladies”.

  37. Are they free-range ladies?

  38. Taktix,

    I think Inflatable Noam is more environmentally friendly (if not as friendly in other ways).

  39. Taktix, are you having your ladies imported from the lady farms of Eastern Europe, or are you getting organically-grown ladies from the local co-op?

  40. So just eliminate all subsidies and let the market figure it out. I would expect things which require more energy to produce would go up in price, reducing consumption. Sound good?

  41. Hmm, right.

    Scenario 1: You do some work for an hour, walk to the market (1/2 mile) in a half hour, and eat a quarter pounder and feel somewhat healthy. You might break even on calorie consumption or gain a bit; energy goes to good use.

    Scenario 2: You sit on your fat ass in your car in traffic for an hour and a half and feel miserable and eat two quarter pounders with cheese, supersized fries, watch TV. You gain calories and waste energy.

    Which life would you rather live? Most of us are living Scenario 2 and aren’t happy about it…

  42. The guy wants to account 180 calories to the walk-to-store activity, but he doesn’t account for the 80 calories per hour burned by humans at typical non-strenuous awake activities – anything above being a couch potato. So if a person walks 3 MPH for an hour and a half , they spend 180 calories, fine. They drive and hang out after the errand for the rest of the hour, they spend 80 calories plus the gasoline emission. Goodall = Hack. Shill. Bogus.

  43. i’m not sure i buy that bit about buses and trains, j-dageek.

    that may be the case for the -first- person, to be sure – but each additional person doesn’t add that much energy demand.

  44. Steven-

    On the margin I think it’s quite likely that adding one more person to a train adds very little to fuel consumption and CO2 production.

    However, the number of trains and buses run every day, and hence the amount of fuel consumed and CO2 produced, will depend on the aggregate number of people using it.

  45. It’s the difference between the question “The train’s there, it’s going to run anyway, should I use it?” and “There is no train, but if we build one along a route where lots of people would use it, what will the effect on CO2 output be?”

  46. We could also greatly reduce our carbon footprints if we would engage in mass suicide. Any takers?

  47. Warty,

    Well, you have to take into account all the greenhouse gases that are produced by rotting human flesh.

  48. I agree, Mr. Crane, and Dr. T. There’s so many angles from which you can approach the “math” in the egg scenario. When I first saw it, I also started to over-analyze it. Then I told myself to quit being such a #&!$ing dork, say “hmmm, that’s cool”, and move on 🙂

  49. Trains ain’t so easy to figure. It costs a good bit of money to stop and re-start a train.
    So railroads used to know the minimum number of passengers they needed to pick up to make a station stop worthwhile. Unfortunately, as riders declined, the ICC or state authority, would make them stop anyway even if there were no riders for that stop. No wonder passenger operations became fountains of red ink.

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