The REAL Carbon Footprint of Bicycles

firebus's picture

Sure, everyone thinks that bikes are awesome because they get infinity miles to the gallon, but that's just hype!

There's absolutely a carbon footprint associated with bicycle use. From the manufacture and shipping of frames and accessories to the carbon footprint of the foods you eat that fuel your bike, it's clear that bike riding takes an incremental but measurable toll on the environment.

The real question is, "How does a bike's carbon footprint compare to a car's carbon footprint?"

And we can answer that question with the power of the n of 1 research methodology.

Foods

Different foods have vastly different carbon footprints. Meat production, since it's farther up the food chain (and because plants don't fart) tends to be a lot worse. We'll take two values - corn and cheeseburgers - as proxies for vegetables and meats in general, just because they happened to be in the first set of responses from google.

Corn

0.15 pounds of carbon are released in the growing and transporting of 1 pound of corn.

1 pound of corn contains 400 calories.

Corn: 0.000375 pounds of carbon per calorie

Cheeseburgers

9.6 pounds of carbon are released in the production of a single cheeseburger.

1 cheeseburger contains 359 calories.

Cheeseburger: 0.0283 pounds of carbon per calorie

Vehicles

Bikes

It takes 34 calories to bike 1 mile.

Corn: 0.0128 pounds of carbon per mile

Cheesburger: 0.909 pounds of carbon per mile

Cars

1.1 pounds of carbon per mile is released in emissions from a medium sized car.

30% of the overall carbon footprint of a car (amortized over the lifetime of the car) comes from the manufacturing and shipping processes.

Car: 1.4 pounds of carbon per mile

Conclusions

In general the n of 1 bike has a better carbon footprint than the n of 1 car. However, the cheeseburger case is within the same order of magnitude as the medium sized car!

So if you consider someone who eats something much worse than cheeseburgers and nothing but that (Hungry Man dinners I guess?), compared to someone who drives a very tiny car in an extremely responsible way (do they have bio-diesel scooters?) it's possible that there are some edge cases where bikes are not the sustainable choice. And we haven't even considered the carbon footprint of bike manufacturing because I forgot it!

QEDon't.


Comments

Bah. Nonsense!!!

I wouldnt even know where to begin with this nonsense.

Yes the production of a bike produces some carbon
Yes the production of a car produces much much much more carbon. (and What if all the people producing the car ate cheeseburgers? what does that do to your 'n of 1'?)

This blog and your 'calculations' are clearly farcical. You want to say that bikes are as bad as cars in terms of carbon footprint? Just say it, I know you are nuts whether you say it or whether you try to 'prove' it with your magical thinking. So will any person capable of any logical thought. Possibly even some monkeys will know it.

Screw you and your 'n of 1', you have NO idea!!!

:D


firebus's picture

Thanks for your passionate response!

It's definitely an interesting idea to consider the diet of the people who built the car (or the bike). I would love to see Volvo switch to an all-vegan commissary as a way to offset the emissions of their products.

You're right that my goal here is to find some way, however ludicrous, for a bike rider to have the same carbon footprint as a car driver. And I agree that the intent is farcical.

However, I'd like to note that you don't provide any evidence (n of 1 or otherwise) to refute my conclusions, so I can't take your objection very seriously!

Thanks again!


I think this great idea.

I think this great idea. People generally do not eat specific amounts of extra calories to 'fuel' their cycling, they just end up fitter and healthier on the same amount of calories. Has anyone considered the carbon footprint of health care provided to the obese and the unhealthy. Thank you for the article.


idiot.

idiot.


The problem with this

The problem with this reasoning is its infinite in levels. You could argue about the increased mass production of trainers due to being worn out by cyclists. Or the heat a cyclist produces means more air con is needed by people due to warming up the atmosphere. Thats a silly one but you get the idea. It can be taken to any level.

balance bikes


firebus's picture

negligibility

sure, but at some point the data you get from descending another level into carbon footprint hell becomes negligible, and you can stop digging. maybe we're already at that point. maybe we started at that point!

the question i'm trying to answer is whether it's EVER the case that riding a bike is the less responsible option. i don't *think* we need to investigate the impact of more frequent shoe buying to make the call.


are you joking? so people

are you joking?
so people that drive cars do not have to eat?
and do you really think a bicycle commuter lives off of cheeseburgers? lol

do you work for the auto industry?


Omg, but what if I drive car

Omg, but what if I drive car and bicycle every day. May be I am the reason of global warming?


firebus's picture

do you also eat hanburgers?

it sounds like you carry a lot of feelings of guilt. do you think your skin tag problem is a psychosomatic manifestation of this neurosis?


firebus's picture

no

> are you joking?

no. maybe. kind of.

> so people that drive cars do not have to eat?

in this analysis, they are vegans

> and do you really think a bicycle commuter lives
> off of cheeseburgers? lol

i had a really, really excellent cheeseburger after a really hard bike ride just this weekend. it was incredibly delicious.

> do you work for the auto industry?

no.


other factors

There are several factors affecting this:

Calories per hour burned 'resting' (driving):80
www.loseweightclassic.com/countingcalories.html
Or a a cheeseburger every 5 hours. So the driver adds a noticeable amount of carbon.

People generally do not eat specific amounts of extra calories to 'fuel' their cycling, they just end up fitter and healthier on the same amount of calories. Has anyone considered the carbon footprint of healthcare provided to the obese and the unhealthy? Health services carry massive carbon footprints, in the UK the NHS burns 18 million tonnes CO2 per year, that's 2.6 TONNES per person, or 5 grams an hour for every person every minute every day! www.sdu.nhs.uk/page.php?page_id=93


firebus's picture

oh my!

Calories per hour burned 'resting' (driving):80...Or a a cheeseburger every 5 hours.

right, but i'm trying to find the case in which a vegan driver of a very efficient car has a lower carbon footprint than the irresponsibly carnivorous rider of a bike. 80 calories/hour in the vegan case doesn't have a big impact on the carbon footprint.

nonetheless this is an important piece of data - i'll try to include it in an upcoming revisit to this topic...


People generally do not eat specific amounts of extra calories to 'fuel' their cycling, they just end up fitter and healthier on the same amount of calories.

i would challenge that assertion. my own experience is that i eat more when i exercise more, and there's a lot of anecdotal and scientific study that supports this.

for example: http://www.fitsugar.com/Study-Shows-Exercise-Wont-Aid-Weight-Loss-600932...


Has anyone considered the carbon footprint of healthcare provided to the obese and the unhealthy?

but exercising certainly does help keep you out of the hospital (statistically) and that's a great point.

i believe an earlier commenter discussed the trade-off in carbon footprint between dying young and fat (you leave a larger decomposing corpse, but have fewer years of life) and dying old and fit.

a similar argument can be made in support of eating veal instead of beef, and lamb instead of mutton...


I'm not sure I can wrap my

I'm not sure I can wrap my little brain around n=1 analysis, but wouldn't the relevant information to compare carbon footprints between cyclists and drivers be calories consumed over their lifetime rather than expended in a given activity? Neither cyclists nor drivers cease to exist when they're not cycling or driving...I think.


added variable

This is a generalization, and not very scientific... but one could argue that those who ride bikes are healthier and thus live longer and by living longer have a higher carbon footprint. It may be possible that the cheeseburger gobbling, gas guzzler driving dead at 45 by heart disease has a lower carbon foot print than the bike riding vegan who lives to be 90.


This article doesn't take in

This article doesn't take in to consideration that you drive many more miles in a car centric area than someone would bike in a walkable area.

In order for cars to work, things must be spread out. Look at any modern development; houses are grouped together miles and miles away from everything you need on a day to day basis. It's not unusual for someone to commute 50 miles to work!

I live in a city about 1 mile from my work. I bike 2 miles per day on my commute and I pass everything I need (shopping, groceries, etc...) on the way.

The nature of cars makes for a city layout that it not conducive to any other mode of transportation.

Another way to look at the situation: Have you ever pushed a broken down car? It's a lot of work! You're lucky if you can push it a quarter mile on flat ground. It takes a lot of energy to move a few thousand pounds with you everywhere you go. There is absolutely no way you can compare this to the energy required to move yourself plus a 25 pound bicycle.


firebus's picture

yes and no

the suggestion to consider the actual milage of bikers vs. drivers is really very astute, and i think it probably decisively tips the balance in favor of the hamburger-bicycle, while also making it clear that this as much of a city planning issue as it is an issue of personal choice.

however i don't think your point about the energy required to move the weight of bike vs. car is useful. the whole point of this n=1 analysis is to look at the hidden factors - factors outside the simple physics of moving things around - that affect the net carbon footprint of someone who only eats hamburgers and rides a bicycle everywhere.


The carbon footprint of cyclists

You've entitled this argument: "The REAL Carbon Footprint of Bicycles" but discount the manufacture, delivery and maintenance of bicycles. Given that they are most often manufactured in China, where coal-fired manufacturing processes are dominant, and transported half way across the globe to their main markets of Europe and the Americas, the carbon footprint may not be inconsiderable. Where I live bicycle ownership is high but its usage is low (in my car-free household we have five bicycles but only one gets regular use; several have languished in the shed, unused since they were bought, many years ago).

If you discount bike manufacture, etc you must, surely, re-frame the question to read: "How does the carbon footprint of a cyclist compare to a car's carbon footprint?"


firebus's picture

manufacture and shipping

i didn't completely discount it.

in fact, in the original post i said


There's absolutely a carbon footprint associated with bicycle use. From the manufacture and shipping of frames and accessories to the carbon footprint of the foods you eat that fuel your bike

but then i kind of forgot about it later, huh?

iirc, when i did my n=1 research on the carbon footprint of bike manufacture and shipping it was totally negligible when compared with the car's manufacturing...but maybe that's a false memory and i just forgot.

i'll update the original post soon to reflect this, thanks for the catch


The problem with this

The problem with this arguement is when you produce corn( for example) it takes carbon from the atmosphere and this is in turn relaesed by the bike rider through cellular respiration, thus a closed carbon cycle is established. When stored carbon ( in the form of fossil fule ) is added to the atmospheric carbon cycle it has a profound negative effect. While some carbon is expelled in the manufacture and shipping of a bike it is much less than that of a car, and a good bike has a longer lifespan than a car, plus exersise is good for you. People that ride their bike to work doet eat cheeseburgers. Your arguement is a weak one.

i dont own a car, why should you


firebus's picture

No problems

Thank you for your well-reasoned comments.


The problem with this arguement is when you produce corn( for example) it takes carbon from the atmosphere and this is in turn relaesed by the bike rider through cellular respiration, thus a closed carbon cycle is established.

No, this is not the case. Farming - especially modern agriculture with its diesel engines and petroleum-based fertilizers - has a net positive carbon footprint. The carbon removed from the atmosphere by crops is much less than the carbon released by the farming process. The n-of-one studies that I used to construct my argument take that into account.


While some carbon is expelled in the manufacture and shipping of a bike it is much less than that of a car

I agree. In fact, I completely ignore the carbon footprint of bicycle manufacture and shipping in my argument for this reason. I don't think it makes a difference.

However, I do include the carbon footprint of manufacturing the car. So considering the carbon footprint of bike manufacture and shipping can only make things look worse for the bike.


plus exersise is good for you.

That is completely irrelevant to the question of carbon footprint, although it certainly is a factor in favor of bicycles versus cars if you consider the issue holistically.


People that ride their bike to work doet eat cheeseburgers.

I ride my bike to work and I eat at least one cheeseburger every week (on Thursdays)! Please provide a citation if you'd like to argue that, generally, bike riders consume fewer cheeseburgers than car drivers.

You'll also need evidence to suggest a causative link between bike riding and reduced meat consumption if you really want to affect this argument.


Cheeseburgers

I bike so that I can eat whatever I want. That being stated, people who drive cars often seem to eat more than me. I've actually observed that I eat less than most people even though I burn way more calories than them. I think this has to do with my fitness and metabolic rate or something. It's an interesting analysis (that I disagree with), but ieven if what you argue is true, I still hold moral superiority over car dependant people. This is mostly due to the fact that once my bike is bought, it is mostly selfsustaining, while automobiles need gas which is mostly shipped from far away, and often corrupt places.


firebus's picture

OTOH

A fatter corpse will release more greenhouse gas than a skinny corpse.

And more fat people dying younger would lead to an increase in this form of carbon pollution.

I suppose we'd need to evaluate whether or not a body fat is a carbon sink - on the one hand, we are storing carbon in fat. On the other hand, there's an ongoing cost in calories to maintain that carbon sink, and those calories have a carbon footprint.


This is quite the touchy

This is quite the touchy topic, one I have never thought of. I think whether someone is burning off more carbon while eating a cheeseburger than cycling, does not make the cheeseburger a better option. This is a bit of a silly discussion, but a very entertaining one to say the least. Our society as a whole needs to start eating healthier, reducing the sedatary lifestyles and thinking about the environment more.


Carbon Footprint of Exercise Bikes

You can offset the carbon footprint of a bike by turning it into a stationary exercise bike and generate electricity with an attached generator. A hotel near Copenhagen International Airport does just that - and rewards guests with a free meal!

Read more: http://news.cnet.com/8300-5_3-0.html?keyword=stationary+bike#ixzz1VJJMD9...


firebus's picture

Wishful thinking?

I'm not sure I agree with this analysis. The energy generated by the stationary bike is offset by the carbon footprint of the food consumed to power the stationary bike.

To get net carbon savings (which could be applied to offset the carbon footprint of the manufacture of the bike), you'd have to have a lower total carbon footprint per kilowatt than the method of electricity generation that you're replacing. Feel free to follow up with an n = 1 evaluation if you like.


You could argue about the

You could argue about the increased mass production of trainers due to being worn out by cyclists.


firebus's picture

Oh, that's so true

If you're driving a car, you can pretty much wear the same clothes every day! Cyclists get all nasty. That's gotta have a significant impact!


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