Environmental Cost of Producing a Bicycle

[mgarl10024]

I was cleaning the bike earlier and a thought popped into my head - "I wonder how many miles I'd need to do on this bike before the costs of it's creation are saved".

So, as this question can run and run, I thought I'd keep it quite simple. I need:
a) the environmental cost (kg of CO2 would be excellent) of producing (and transporting) the 'average' bicycle.
b) the average car's CO2 emissions per mile.

This would tell us the number of miles I could do in a car for the same environmental price as producing the bicycle.
If the value for a/b is a large value (as I suspect), we may need to think about bike consumables. For example, if I need to do 20k miles, then I'll need to replace a lot of the bike - pads, cassettes, chains, and a good few tyres.

It may even be that someone has done this calculation already as it must be a common question, but some Googling couldn't see anything obvious.

Does anyone have any links/data that can help here? It's not a scientific question so ultimate precision isn't essential, but it is a fun mental exercise...

Thanks,

 

[Arch]

This is mainly about the carbon footprint of food, but it mentions a figure of "50g per mile to take into account the emissions that are embedded in the bike itself and all the equipment that is required to ride it safely" So that's not quite the figure you asked for, but a milage figure.

http://www.guardian.co.uk/environment/2010/jun/08/carbon-footprint-cycling

This suggests an average car emission of 164 g/km

http://www.carpages.co.uk/co2/

Bloody hell, could they not just stick to miles!

If it's just a case of converting km to miles, it's 102g per mile.

But you haven't specified taking into account the carbon tied up in the production and transport of the car - why not? Add that into the car figure.

And of course, it depends on the bike and the car. An aluminium or titanium bike has a bigger footprint than a steel one, and a greater environmental impact in the production of raw materials. Ship a frame from Taiwan, and it's worse than a frame built here in the UK.

 

[mgarl10024]

But you haven't specified taking into account the carbon tied up in the production and transport of the car - why not? Add that into the car figure.

Great links - thanks Arch!

You're absolutely right.
My thinking was that I already own a car and that I would be using it regularly. However, the bike is something new, which I have bought.
What I have forgotten though is the car's maintenance environmental aspects too. hm...

I guess I should rephrase the question:
"How many miles (including the car's environmental maintenance costs) would I need to do on my new [aluminium and made in Taiwan] bike (given its environmental maintenance costs too) instead of in the car, to negate the impact of the bike".

Does that make a bit more sense?

 

[mgarl10024]

This suggests an average car emission of 164 g/km
...
If it's just a case of converting km to miles, it's 102g per mile.

I think you may have gone the wrong way. A mile should be worse than a Km?

 

[darth vadar]

I think you might need to get out more !!!

 

[al78]

I think you may have gone the wrong way. A mile should be worse than a Km?

Yes, the 164 needs to be multiplied by the number of km in a mile, approximately 1.6.

Therefore the relevant figure is 262g/km.

 

[mgarl10024]

I think you might need to get out more !!!

You're not the first to have said this, and you certainly wont be the last.

 

[mgarl10024]

Yes, the 164 needs to be multiplied by the number of km in a mile, approximately 1.6.
Therefore the relevant figure is 262g/km.

262g/MILE.

 

[Arch]

Yes, the 164 needs to be multiplied by the number of km in a mile, approximately 1.6.

Therefore the relevant figure is 262g/km.

Thankyou, I had doubts but couldn't get my head round it.

My thinking was that I already own a car and that I would be using it regularly. However, the bike is something new, which I have bought.
What I have forgotten though is the car's maintenance environmental aspects too. hm...

That's the case for you. For me I own the bike(s) already, it would be the car that was new (if I had to get one).

I guess I should rephrase the question:
"How many miles (including the car's environmental maintenance costs) would I need to do on my new [aluminium and made in Taiwan] bike (given its environmental maintenance costs too) instead of in the car, to negate the impact of the bike".

um.. some? The more the merrier?

No, I will work this out. Call the bike 50g/mile and the car 250g/mile, which is being generous to the car. Do a mile on the bike instead of the car, and you save 200g. Hasn't that already paid the bike off, so to speak?

 

[Arch]

Thankyou, I had doubts but couldn't get my head round it.



That's the case for you. For me I own the bike(s) already, it would be the car that was new (if I had to get one).



um.. some? The more the merrier?

No, I will work this out. Call the bike 50g/mile and the car 250g/mile, which is being generous to the car. Do a mile on the bike instead of the car, and you save 200g. Hasn't that already paid the bike off, so to speak?

No,you dope, it hasn't. It's paid it off per mile, but the total carbon footprint of the production and transport process is more than 50g. But I can't imagine it would take long to offset it.

 

[the snail]

This is mainly about the carbon footprint of food, but it mentions a figure of "50g per mile to take into account the emissions that are embedded in the bike itself and all the equipment that is required to ride it safely" So that's not quite the figure you asked for, but a milage figure.

http://www.guardian....otprint-cycling

This suggests an average car emission of 164 g/km

http://www.carpages.co.uk/co2/

Bloody hell, could they not just stick to miles!

If it's just a case of converting km to miles, it's 102g per mile.

But you haven't specified taking into account the carbon tied up in the production and transport of the car - why not? Add that into the car figure.

And of course, it depends on the bike and the car. An aluminium or titanium bike has a bigger footprint than a steel one, and a greater environmental impact in the production of raw materials. Ship a frame from Taiwan, and it's worse than a frame built here in the UK.

er.. 164g/km = 262g/mile?

I think these sort of calculations are difficult if not impossible to work out with any meaningful accuracy. If you look after your bike, the frame and some other parts should last a lifetime, so the built in co2 gets less significant over time. Anyways, anybody who cycles is entitled to be ultra-smug, any fool no that

 

[Night Train]

The thing is you need to consider the carbon foot print of the fuel too. For both the car and the bike there will be a 'cost' to acquiring, processing and transporting the fuel to you.

You could go further and include the carbon footprint of your whole existance that lead up to making the decision to use one or other form of transport. Also the carbon foot print of the other people invoved in the whole productiona dn delivery chain.

It goes on infinately and becomes more and more meaningless.

 

[deptfordmarmoset]

I've wondered about this but new factors always keep occurring to me, making any estimate more and more difficult to achieve. For example, should you take into account the cost of maintaining a road system suitable for motorised traffic compared with the theoretical cost of a road network suitable for cycling, horse-riding and walking? So taking away the cost damage caused by horseshoes on the carriageway, cycling becomes cheaper.

And after standing at a red light in the middle of the A2 yesterday for over 5 minutes - ie, through over 3 phases without ever getting anything like a green light - it's worth bearing in mind that the electricity cost alone for traffic lights alone must be very substantial. And traffic lights may be there for cyclists to obey, but they certainly aren't there because of dangers presented by cyclists. (Nobody has ever named a single set of traffic lights in the UK that has been installed because of dangers posed by cyclists.) That's a cost which must be therefore attributed to motorised transport.

 

[jonesy]

This is mainly about the carbon footprint of food, but it mentions a figure of "50g per mile to take into account the emissions that are embedded in the bike itself and all the equipment that is required to ride it safely" So that's not quite the figure you asked for, but a milage figure.

http://www.guardian....otprint-cycling

...

This sort of calculation, trying to calculate a CO2 emission factor for cycling based on food consumption, is extremely dubious, as it assumes that people will eat additional food in proportional to the distance they cycle. That is an extremely bad assumption. The amount people eat is affected by a far greater range of variables than the amount of physical activity undertaken, especially when talking about the relatively short distances typical of cycling to work for example. Imagine a situation where you have two people who eat exactly the same amount of food, and have the same distance commutes, but one drives and the other cycles. If you count part of the cyclists' food as a transport emission, where do you count the CO2 in the driver's food? Unless food consumption really can be shown to have a direct relationship with distance, its associated emissions ought not be counted as transport emissions. They shouldn't be ignored of course, but are far more logically accounted for in the carbon budgets for agriculture and food production.

 

[mgarl10024]

Thanks for the replies - very helpful.

I'll simplify the question so we can come to a relative answer.

- The car is already owned
- The bike is new
- I'm overweight, so will not need to up my eating. So we'll remove the extra cost here. We'll assume I'm already eating, and would already have been eating, enough food, so cycling incurs no extra cost here.

Cost of Bike Production
Average weight of a bike:
http://wiki.answers....e_bicycle_weigh = 30lbs (30/2.2 = 13.6kg)
http://www.last-word...ee_id/2878.html = 35lbs (35/2.2 = 15.9kg).
I remember weighing my bike on the scales and it came in at about 16kg.

CO2 from the metals.
http://www.bikeradar...-it-seems-28911 says "According to Trek, the extraction of a single kilo of the raw steel, aluminium or carbon used in their frames releases 1.3, 4.6 and 5kg of CO2 into the atmosphere respectively. "
http://www.tenerife-...-frame-produce/ says 6.8kg for 1kg aluminium.

Now, I know that my bike isn't made completely of aluminium, but most of the bikes on it should either be alumiunium, steel, plastics or rubber.

Rubber and Plastics are horribly complicated and most of the bike isn't made of them as far as I'm aware, but http://timeforchange...s-CO2-emissions says 6kg per kg for the plastic, and I'll assume the rubber is around the same (I can't find a resource for this).

That would make the average cost per kg (4.6+6.8+6+6/4 = 5.85kg per kg, and assuming that the bike is mostly aluminium/steel this estimate is probably not in favour of the bike.

Therefore, total cost = 16kg of bike at 5.85kg each = 93.6kg cost.

Given Arch's figure of 262g/mile, that means (93.6/0.262) = 357 miles.


Getting The Bike Here - Sea
http://timeforchange...-shipping-goods says that it costs "10g to 40g" to transport a metric ton of freight 1km.
http://www.mapcrow.i..._Taiwan_TW.html says Taiwan is 6117 miles away, which is (6117*1.6=9787km). I know the boat would take a roundabout route, but this is about the best I have.
My bike is 16kg, which is 0.016 metric tonnes.
Cost (higher end of range, 40g) = 0.016*9787*0.04 = 6.26kg or 23.9 miles.


Getting The Bike Here - Air
http://timeforchange...-shipping-goods says that it costs "500g" to transport a metric ton of freight 1km.
http://www.mapcrow.i..._Taiwan_TW.html says Taiwan is 6117 miles away, which is (6117*1.6=9787km)
My bike is 16kg, which is 0.016 metric tonnes.
Cost (500g) = 0.016*9787*0.5 = 78.3kg or 298 miles.


Total Mileage
Sea Freight: 357+23.9 = 380 miles.
Air Freight: 357+298 = 655 miles.



How does that sound to people on here? Is my working correct and my assumptions not too generic?