Ask the EcoGeek: Walking Worse than Driving? No.
by EcoGeek.org on 08. 9.07
Dear EcoGeek,
I just saw a kinda disturbing article on fark.com and wondered what you would think of it. Could walking really be worse of the environment than driving?
- Seulswalker
Seulswalker,
When I read your question, I assumed that there was no way the article had any credibility... that it was written by an angsty high school student who was sick of people telling him what to do. But I was wrong, and that is scary.
Someone took the results of a scientific study on how inefficient our food production system is, did some really bad math, and then found themselves a glorious headline that would send shock waves throughout the blogosphere. You could call it sensationalism...I just call it evil.
Here's the "scientific" basis for their thesis:
"Driving a typical UK car for 3 miles [4.8km] adds about 0.9 kg of CO2 to the atmosphere ... 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."
Now I hope we can all see some gaping holes here, but maybe not all of them at first glance. So let's go through the five I came up with one by one.
Most obviously, this assumes that 100% of the calories we use to walk come from beef. Actually roughly 75% of the calories most people burn come from plants (usually in the form of carbohydrates.) Plant calories are much less energy intensive to create. This leaves out Atkins dieters...but I hope they're offset by vegetarians.
Second, We need to pick our battles in this war. As both driving and eating inevitably add to the amount of CO2 in the atmosphere, these are both issues that we should be working on. But if we go 100% I'dl rather remove cars than exercise from my lifestyle. Not because it's better for the earth, but because it's better for me.
Third, we have the supposed correspondence between exercise and consuming food. Yes, if you exercise, you'll have to eat food to replace those calories, but the obesity epidemic is a testament to the fact that, frankly, most people eat because they want to, not because they need to.
Forth is probably the least obvious hole...but it might turn out to be the most important. Walkers don't travel thirty miles to go to the grocery store, but drivers do. Walkers opt for the corner grocer over the Wal-Mart. Driving doesn't encourage waste because just because it's inefficient. It also exponentially increases the amount of ground we can cover, creating sprawling cities and destroying local economies. Even if walking produced four times more CO2 emissions per mile than driving, walking reduces the number of miles traveled for most errands by ten to forty times.
Fifth, and this really is a huge omission, the study counts every piece of CO2 produced in the creation of the cow, but it only counts the carbon produced by burning the gasoline for the car. That'd be like only counting the CO2 that we exhale while walking. The hidden carbon costs of automobile travel are gigantic, more than double the final emissions for the car. They include the cost of mining and smelting the steel, pumping the oil, shipping the oil, refining the gasoline, shipping the gasoline, creation and maintenance of roads, construction of the car, etc etc. To leave out these costs while counting every drop of fertilizer sprinkled on a cow's pasture is extremely foolish and, frankly, disappointing.
So, in short, walking is better for you and the world than driving is. Biking, being even more energy efficient than walking, however, is indeed better for the Earth. However, the point of the original study rings true. Our food production system is foolishly inefficient and unhealthy. It must be reformed in order for this to become a healthy and sustainable world. And for more on that, I suggest Bill McKibben's Deep Economy.
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Another thing to consider is that plant based food(minus transportation and packaging) doesn't really contribute to overall increases in CO2. Gasoline is not grown and does not absorb atmospheric CO2 during production the way vegetables do. Eat a carrot, not a gow.
http://www.michaelpollan.com/omnivore.php
Omnivore's Dilemma is also a great resource for thinking about our production of food.
This post was great except for this last bit
"So, in short, walking is better for you and the world than driving is. Biking, being even more energy efficient than walking, however, is indeed better for the Earth. However, the point of the original study rings true."
After pointing all the floors in somebody else's study you then go and make this statement with out backing it up.
You pointed out"the study counts every piece of CO2 produced in the creation of the cow, but it only counts the carbon produced by burning the gasoline for the car" but then didn't do the counting yourself either. And you pointed state " Biking, being even more energy efficient than walking, however, is indeed better for the Earth" without any study or evidence on the CO2 used in producing the bike etc.
Theoretically, the net CO2 added to the atmosphere from walking would be zero, since biomass is used as the fuel source (plants take up CO2 from the atmosphere, cows eat those plants, people eat the cows, people exhale CO2 into the atmosphere, plants take up more CO2 from the atmosphere)
Although we should know this by now, I think the take away message should be that it is really f-ing easy to manipulate a life cycle analysis (or a quick efficiency comparison like this) to tell you exactly what you want. All you need is some bad assumptions and to cherry pick some data, and you're all set.
This sounds similar to an analysis I heard on TheWatt (what's happened to that site?)
In calorific values, a person on a bike gets around 1500mpg.
Factor in shipping 6 bananas from the carribean to the US to provide your food and it drops to around 500mpg (I think).
And if you eat a highly processed breakfast cereal to get your energy it drops to a frightening 56mpg!
But come on, the car driver has to eat too, so that is in addition to what the car consumes.
And people have been walking for quite a while! The graphs of CO2 increase seem to correlate a little better to large scale car use than to when humans got up on 2 feet......
This happens evry time you comprehensively break down any environmental issue.
Even if the point really was something else, the *lesson* is that even if you find the most 'green' option, the crisis is not going to be resolved.
Sometimes I think people don't understand exactly how many 6.2 BILLION is! Finding the greenest option buys us some time, but the only FIX is to improve global standard of living to western levels so that the population can begin to decline. If the greenest option impairs that progress, then it's not the greenest option.
With respect to driving vs. walking: we have to promote the quality of life gained from vehicle-restricted communities. Hopefully the rest of the world can see that North America went too far with the automobile's gift of 'independence' - that we lost 'community' in the process. Our attempts to regain that community by restricting downtown auto use is a powerful message to the rest of the world, that driving can, and will, impair standard of living if left unchecked.
The premise of this math exercise is wrong. We do not necessarily REPLACE calories after we exercise. Obesity is more complex than that. Your hypothalamus has a thermostat type setting for caloric intake. Athletes have to eat some more due to more burning and muscle needs but the average person usually eats the same caloric intake per day more or less. As well, if you are to lose weight, the key is to increase your daily activity and lower your calories to your ideal weight goal. So this study is nonsense.
Signed,
Dr. K.
There was a similar hatchet-job for washable 'real' vs disposable nappies in the UK recently.
Just look for the sponsor of the 'research'...in this case it was the makers of Huggies!
Umm...even if you drive you still have to eat. shouldn't the equation for the car take that into account? (the article presents such an absurd and arbitrary analysis...hard to even imagine someone thinking it has significance)
There is another point:
You have to DRIVE the car. In order to drive it, you consume calories. It's not as much calories as walking, but calories anyway. I've made a few calculations here, and it amounts to anywhere between 7 to 11 calories, driving 3 miles (different references, different numbers).
With everyone becoming heavier wouldnt it be great if you could quote how overwieght prople are not in pounds or kilos, but in kWh's?
I agree that being healthy is a good enough reason to walk or bike, but just as other commenters have mentioned, when you walk, think of all the materials used to harvest the food, package the food, ship the food, prepare the food, and not just growing the food. On top of that, think about all the processes to make the clothes you wear to walk, the shoes, etc. So it still might be cleaner to walk even adding all those things in, you can't just say: the plant was grown, picked and place on your plate ready to eat with nothing in between for all cases. Also, even though there are increasing numbers of vegetarians in the world, I think there are many more people in the world that would rather eat a meaty burger than a vegetarian meal.
You also are not taking into account if a car held, say 4 people in it. Now you reduce the footprint of the car by almost 4x (compared to taking 4 cars) and increase the walking footprint by almost 4x. You also don't take into account if the trip is long, say a week of traveling. The person is still breathing out CO2 regardless if they are walking or not; not to mention they are eating regardless if they are walking or not, the places they sleep, the energy used to keep them warm at night, etc.
If you really wanted to compare apples to apples (or close to it), a single person walking would be more like a scooter going to the store or a motorcycle.
So there are many situations that could sway one way or the other. I'm really just playing devil's advocate here. Like I said, I believe exercise is one of the best things for you.
There's a question I'd like to ask, also in that article. Is that any truth in saying that "Organic beef is the most damaging because organic cattle emit more methane."? Apart of any other benefits of organic is that really true?
Seeing as the Basal Metabolic Rate is probably around 2,000 kcal for an adult male, the calories expended simply to stay alive at rest are equivalent to maybe 2 hours of walking.
Clearly, we should all stop living and instead populate the world with cars that drive themselves 3 miles every 2 hours.
What a dumb, dumb "study" this is.
this reminds me of an argument i actually heard a lady tell her friend: that convenional produce was actually BETTER for you to eat than organic, that we actually needed those pesticides...her son went to UCD so she should know.
it's just sounds like voodoo math to me. the driver eats, and the walker eats, not necessarily beef. oh, there's just too much silliness to get into this, i can't even believe it merits us getting all excited about.
talk you folks later, i've got to ride my bike to the nearby natural foods store and buy some locally grown produce. i'd walk, but i wouldn't want to destroy the environment......
Thank you for clearing this up, I was shocked when I read the original article.
Excellent, well thought out and well needed rebuttal. Thanks for posting it, TH!
Robbie--When the author said the original study rings true, I believe he was talking about the original research that the bogus article was referencing--specifically about the inefficient energy use put into food production--not the craptastic article itself. And I think it's an important point to note that just because some jerk manipulates scientific data to get their 15 minutes of fame, it doesn't mean the original data isn't correct and well worth our time to know.
you spelled fourth wrong.
Actually, your Forth[SIC] argument may not be all that true -- at least in Wal-Mart's case. I live in Suburban NY. There are two Wal-Marts less than 5 miles apart. You could walk to either.
I mentioned this to my wife and she said she has read that Wal-Mart tries to build their stores within walking distance of the largest portion of the target customer in dense population areas. This, apparently, because many people in ther demographic don't own automobiles.
Forth is probably the least obvious hole...
Did you misspell fourth, or are you talking about the programming language?
And let's not forget there's food, and then there's FOOD. We might get our calories from Caribbean bananas and Chilean grapes ... or we may eat sweet corn, carrots, and cereals produced within our own counties. Whole Foods and the like are now emphasizing locally grown produce (and even meat). It's only a matter of time before all of us start picking the local stuff over the imported as a matter of course.
And on the question of bicycles, even if a bicycle requires a substantial energy or CO2 commitment to produce (and I don't know that it is especially bad in any case) it can last 20 or 30 years with absolutely minimal maintenance, parts, and labor. Try that with a car.
Not to mention that walkers , when shopping, tend to buy way less . Walkers tend not to buy superflous crap they don't need or impulse buys. This in itself would rid the world of Wal-Marts.
The concept of food miles is based on this same flawed logic. A simplistic comparison of miles to market ignores the dramatic environmental economies of scale provided by larger vehicles/vessels. Using ton/miles per gallon as a de facto for co2 emissions we should always find that ships are better than trains, followed by trucks, vans, cars and mopeds. Using typical or average loads rather than maximum possible load is always a good idea if you want the real world difference rather than the academic theoretical.
Of course food miles then compounds this sin by ignoring the total energy used to produce the food that is being transported. A CO2 comparison between British and New Zealand butter would have to include the CO2 produced making winter feed for British cows as well as any effect the winter feed might have on bovine methane production.
I would also like to add that we don't stop breathing when we drive...
dave: organic beef produces LESS methane. cows are designed to eat grass and when they are forced to eat corn mixed with random additives it results in more methane filled cow burps and farts.