Slashdot Mirror
What's the Carbon Footprint of Bicycling?
Hugh Pickens writes "Brian Palmer writes that although none of the major manufacturers has released data on their energy consumption and how much greenhouse gas making a bicycle requires, Shreya Dave, a graduate student at MIT, recently estimated that manufacturing an average bicycle results in the emission of approximately 530 pounds of greenhouse gases. Therefore, given a 'typical U.S. diet,' you would have to ride your bike instead of driving for around 400 miles to cover the bike's initial carbon footprint. However, calculating the total environmental impact of a mode of transit involves more than just the easy-to-measure metrics like mileage per gallon. Using a life-cycle assessment, Dave concluded that an ordinary sedan's carbon footprint is more than 10 times greater than a conventional bicycle's (PDF) on a mile-for-mile basis, assuming each survives 15 years and you ride the bike 2,000 miles per year. What about other ways to get to work? According to Dave's life-cycle analysis, the only vehicle that comes close to a bicycle is the peak-hour bus — and it's not really that close. A fully loaded bus is responsible for 2.6 times the carbon emissions total of a bicycle per passenger mile while off-peak buses account for more than 20 times as many greenhouse gases as a bicycle. What about the carbon footprint of walking? 'Walking is not zero emission because we need food energy to move ourselves from place to place,' says environmentalist Chris Goodall. 'Food production creates carbon emissions.'"
The whole carbon footprint thing is overrated. and the carbon credits is just a way to make businesses feel better about wasting and polluting. What's the carbon footprint of sleeping? What's the carbon footprint of sitting on the couch watching TV? What's the carbon footprint of eating a microwave pizza? What's the carbon footprint of teleporting? geez
Since the whole carbon footprint thing is so grim, what way of doing myself in has least impact on the atmosphere. I was thinking of getting sucked into a jet engine, killing two birds with one stone as it were.
"He's lost in a 'floyd hole"
By growing his bamboo bicycle frame into the shape he wants. Fairly cool!
http://www.wired.com/gadgetlab/2008/09/growing-bamboo/
No one ever had to evacuate a city because the solar panels broke!
I'd be surprised if there were many bicycle owners who didn't do 400 miles in one year, especially if they're using them for a daily commute. 2 miles each way every weekday will do that in 6 months. And bikes last for years. Mine used to belong to my father, who did 20 mile rides on it on a regular basis.
The 'instead of driving' thing makes this a bit more complex though. I don't have a car, so most of the time I use the bike the alternatives would be walking or getting a bus. The energy usage of the bike versus walking is difficult - going in to town I need to pedal about three times to coast there. Coming back, there's a gentle slope where it's about as much effort as walking, followed by a steep hill where the wheels aren't much help and I have to lift the mass of the bike as well as myself up the hill. If I bought a car, then I'd have to factor the cost of producing the car into the calculations.
I am TheRaven on Soylent News
Let's see, walking is not zero carbon because of the food energy.
After the carbon cost of making the bike, biking's not zero carbon either, for the same reason.
But I only ride my bike for exercise, thus I don't save anything vis-a-vis my commute to work, and I have the food energy cost. Therefore my bike riding definitely has a carbon footprint.
Oh noes. Guess I better stop riding and turn into an obese blob for the sake of the environment.
...it is still going to save the rider in gas money (provided they're riding the thing whenever they can, obviously a bike rotting in a garage does no one any good).
I see a lot of people screaming left and right about how all these technologies like mass transit and solar power and such are "just as bad", but the end result is always the assertion that "we should just do whatever because nothing we do will ever help so screw it". Here in Madison, WI, where there are a fair number of cyclists, there are still those people that go out of their way to prevent them from riding. Every article about a bike riding event warrants thousands of comments about how much these people wish they could go drive over the riders in their Canyonero and other such crap.
Every little bit helps, does it not? And why so much hostility for green energy initiatives? Are we just going to keep on burning oil and coal for power? I mean, clearly we need to start coming up with alternatives, right?
you would have to ride your bike instead of driving for around 400 miles to cover the bike's initial carbon footprint.
And my 11 mile round trip to and from work? Already covered in two months of the first year.
Bikes also damage roads far less than cars do. A heavy bicycle weighs around 30 pounds
Slightly misleading, as it doesn't take into account the 170-pound rider on the bicycle. But I've read that the damage done to a road by a vehicle is somewhere between the third and fourth power of the weight per axle.
My current way of getting to and from work is a bicycle during good weather or an off-peak bus during rain and during late fall and winter. But the article says off-peak buses are horrid. Should I change it?
You're doing it wrong.
The manufacturing process of the bicycle will have roughly the carbon footprint of manufacturing a car door. And these researchers want us to think you have to put 400 miles on the bike before break-even?
I'm sorry, but if they can make such an obvious biased mistrake, why should anybody give even a moment's thought to the rest of their study?
Cheers,
b&
All but God can prove this sentence true.
Like pedestrians . . . (cue snare drum rim shot).
Have you ever tried to cross Randall at Dayton on foot? With the walk sign on? With some fine upstanding citizen on a 15-speed bombing through the red light? Or at that marked crosswalk across University near where Bob's Copy Shop in University used to be? When that walk sign is on, I guess the red light for the cross traffic doesn't apply to cyclists in the bike lane.
Of course, as a pedestrian, you are never of any danger of being hit, with the force of an NFL free safety making a flying tackle, only taking the hit, on cement, without helmet or pads, because the cyclists know how to weave around any pedestrian who dares to enter a crosswalk.
Seriously and all snark aside, I would have a lot more sympathy for the concerns of cyclists if there was a little more respect for people on foot. Is that so anti-green?
My favorite is the leap from "Well, making solar panels and other clean energy technologies, as well as buses and bicycles, causes pollution, too, so we might as well just keep on truckin' because fuck it."
You know, it doesn't happen very often, but sometimes I really envy those that think that they're going to be raptured up to heaven or something one day, or that the world is going to end in 2012, so that they don't have to worry about a fucking thing in their lives beyond the immediate future. Must be nice to not care at all about the effect you have on the world around you, but I still don't understand why they have to try to prevent anyone else from at least trying. Even if I thought every person around me was going to die in a zombie apocalypse, I'm still not going to slash the tires on their getaway vehicle. Why so many others feel the need to do so is beyond me...
There was a lot of carbon locked up in oceans of oil and mountains of coal underneath the earth's surface which is being increasingly released into the atmosphere over the last hundred years. This amount of carbon was not 'floating' around in the ecosystem because it was locked up underground but now, since the industrial revolution, it is being released into the ecosystem at a rate that would never be possible naturally. This is otherwise known as the 'carbon footprint'.
Even worse, don't forget that it takes ten pounds of crude oil to deliver a pound of food to a plate, when everything is added together.
Look, you need to be careful when you use statistics from sources that don't spell out exactly how the figure is generated. A quick google http://wiki.answers.com/Q/How_much_does_one_gallon_of_crude_oil_weigh search of how much oil weighs per gallon comes up with about 7 pounds per gallon for light sweet crude. Now, today's oil price for West Texas Intermediate is $85 per barrel http://www.oil-price.net/. There are 42 gallons per barrel so the cost per pound is
42 gallons * 7 pounds per gallon = 294 pounds for a barrel
$85 / 294 pounds = .29 cents per pound
So according to your statement above, food requires 10 pounds of oil per pound of food, SO the average pound of food should cost at least $2.90 because that is how much it would take to cover just the cost of oil. It ignores cost of land, labor, equipment, seed, or processing and profit to farmer and retailer. Sorry, that doesn't sound right. Staples (corn, rice, wheat, potatoes) certainly don't cost that much per pound. Legumes don't. Most fresh fruit doesn't. Milk doesn't. Cheese will, but some cheeses on sale won't. Vegetable oil doesn't. Olive oil might. Most meat will cost at least that much. Maybe the figure you quoted was just referring to meat or processed foods.
In any case, before you use figures, just make sure that number makes sense. (I am reminded of the time in college when as a grader in a physics class, the students were asked to find how high a pressurized leak on a water tank would shoot into the air. Two student's answers had the water at escape velocity speeds, sending them into orbit the earth.)
If it costs $2700, that implies there's a fair bit of energy going into making it, whether directly or indirectly. If that's mostly labor costs, what do you think those employees do with that money?
Certainly there are greener and less green alternatives when looking at similar price points, but I don't see how spending 10x the amount on a bike could possibly be considered a "greener" alternative.
The only solution to the carbon problem is to exterminate the population and leave the bodies out so that you don't leave a carbon footprint trying to bury them. Turns out the nazi's and the khmer rouge were more green than greenpeace!
The article over simplifies the concepts of sustainable transportation and calorie consumption in the same ways thinly veiled "anti-green" articles attack more sustainable forms of energy production. In the energy debate, there are arguments against solar because of the lack of sun in Seattle, arguments against nuclear energy because of the waste that would be created if the entire world was put on nuclear power, and arguments against wind farms in natural wildlife reserves. They use worst-case scenarios to judge methods of alternative energy creation instead of how they would actually be implemented.
The same goes for sustainable transportation and this article. FTFA: "If you walk 1.5 miles, Mr. Goodall calculates, and replace those calories by drinking about a cup of milk, the greenhouse emissions connected with that milk (like methane from the dairy farm and carbon dioxide from the delivery truck) are just about equal to the emissions from a typical car making the same trip." And that assumes I'm going to drink a milk. From a cow. After a warm walk. Who the hell drinks milk after getting sweaty? People drink water or have some fruit! Instead of postulating what the worst can be, why not survey people to find out what *actually* happens? Or worse-- why bother considering food at all?
Even in the "worst-case" scenario where everyone in the USA stopped driving private vehicles and just rode bikes and public transit as necessary, would we all focus on beef to make up for our additional caloric needs? And would it make such a massive hit to the environment when compared to to complete loss of people buying and driving their own cars? -- Not that I'm advocating such pie-in-the-sky thinking, but if you want to bring in cow-pollution, let's really compare it to the pollution from manufacturing, transporting, using, and disposing of cars. I can be disingenuous, too!
Lastly, focusing only on the mythical carbon footprint or GHG emissions of any mode of travel is BS science. It's only for "wow" and "fear" effect. You have weigh to the relative benefits of a mode for the passenger, operator, and third parties (cost, health, pollution, etc.), and the habits that may come along with regularly using a mode of transportation (lethargy and car driving for example). There are entire schools of study on sustainable transportation and summarizing it in a childish (trollish?) article is silly.
It's not about finding single a form of transportation that is a "winner"-- it's about finding a mode that is best for you, where you are now, where you need to be, and when you need to be there. Sometimes driving your truck alone on the road is sensible-- like when you're heading over to buddy to help him move. Other times, it's stupid-- like when you drive 3 blocks down the street to pick up some tic-tacs.
Regular Trips:
Walking is suggested for round trips under two miles -- It helps keep the person healthy and burns no fossil fuels in the process. When you get home, don't raise 40 cows for slaughter.
Bicycling is suggested for trips for round trips under 15 miles (fitness and competency varying) -- It helps to keep the person healthy and burns no fossil fuels in the process. See above comment about raising cows.
Bus Transit is suggested for round trips under 15 miles or longer trips depending on availability-- It burns fossil fuels, but it's like a giant carpool.
Train Transit is is suggested for round trips over 30 miles or longer trips depending on availability-- It burns fossil fuels (directly and/or indirectly), but it's like a giant carpool.
Carpooling and Vanpooling is suggested for 20+ mile commutes -- It reduces the amount of pollution per user in areas where transit is not an option
Irregular Trips
Carpool (see above)
Passenger Jet - In a packed jet and for trips greater than 700 miles, you're actually doing pretty good when it comes to your share of greenhouse gases. The longer the trip, the better since the largest concentration of fuel burning comes at take-off.
You al
Not at all. I'm guessing it's mostly labor cost and profits.
Probably the same things the customer would have done with the money if he hadn't bought the bike, so it doesn't matter.
The carbon footprint thing is overrated, but not useless.
No it is useless because of the lack of consistency. For example in this study did they consider the food usage of someone sitting on a bus or driving a car in their study - I would guess not. In fact since generally our food usage is in excess of our body requirements the difference between a cyclist and passenger is probably not that great, not to mention the health benefits of cycling which will reduce health care needs and so reduce the carbon footprint of that. Hence you end up with some apparently scientifically accurate numerical value such as "250kg" of carbon which has no objective scientific basis whatsoever.
The only way this can change is if there is some agreed upon standard which everyone follows to calculate these numbers. Until then such comparisons are likely to just reflect the political views of the person doing the study and so they really are useless.
There's more reason to question clean energy than that strawman though. Alternatives to gas and coal are expensive and difficult. Realistically solar and wind can only ever provide a fraction of what we need, hydro is regional and situational and has its own environmental issues, as does nuclear, and many such as tidal, thorium and geothermal are a long way from being effective. The easiest way for a western economy to reduce their CO2 output today, right now, is to go nuclear or to build modern coal fired plants which are far cleaner burners than the existing installed base. Both of these options are polictically unpalatable to environmentalists though, so don't expect them to happen anytime soon.
When autos drive slower they consume less fuel, which means that not only are those cyclists reducing their own carbon footprint, they are reducing the footprint of the drivers as well.
That depends on the speed. According to the U.S. Department of Energy, most cars’ fuel efficiency peaks at between 35 to 60 mph. [http://www.fueleconomy.gov/feg/driveHabits.shtml]
A car going 10 miles behind a cyclist at 13 mph will consume about 75% more gas than one traversing the same distance at 35 mph. In addition the resulting traffic jam may cause many cars to be delayed further multiplying the effect. That makes cyclists, when they delay traffic, an environmental hazard.
No, your assumption is incorrect for the situation of following slow moving bicycles in traffic. Ever notice how a vehicle's mileage is stated in two ways, city MPG and highway MPG, and that city MPG is always less than highway MPG? All the reasons that make city MPG less efficient are present when the drivers have to follow the bikers.
Every time they have to hit their brakes, they waste the energy that went into accelerating the vehicle. Any revolutions the engine produces while idling (at stop signals, or any time the driver has his foot on the clutch or any time the automatic transmission's torque converter clutch is slipping, etc.) is burning energy without effect. Any other incidental energy that's strictly time-based (lights, cabin fans, air conditioning, radio) is wasted by the extra time its being operated. Having to electrically power the engine cooling fans to run when the car is moving slower than the surrounding air can cool the radiator is an additional waste.
There is an optimally fuel efficient speed for every vehicle. Faster than that speed and air resistance wastes fuel. Slower than that speed and it's burning the extras I just mentioned.
John
It costs $2700 because these are basically prototypes; from the article, the guy talks about how sales have been growing in "double digit numbers" - they probably make less than a thousand of these per year. If they increase production, the price will probably come down.
Walking IS less inefficient compared to cycling. According to Bicycling Science, 3ed, p. 166, cycling 15mph is about 24 kCal/km (38/mi), walking 4mph is about 55 kCal/km (88/mi). Cycling at 10mph is 15.6 kCal/km (25), 4mph is 8.4 kCal/km (13.5) (assuming you don't waste too much energy staying balanced).
These figures are "incremental above resting". Resting metabolic rate appears to be about 75 kCal/hour, so the 4mph figures for walking and cycling are 19 kCal/mile higher -- 107 and 22.5, respectively. At 15mph, resting contribution is only 5 kCal/mile (43 kCal/mile total).
I hope this helps. None of this is news; all the data and studies are out there, waiting for someone to read them. Two books written decades ago covered all of this -- Food, Energy, and Society by Pimentel, and Bicycling Science by Wilson.
aack -- walking is less EFFICIENT.
...but as an aside, any velocity straight up without a sustaining acceleration will eventually come back down.
No, escape velocity is an initial speed that will "escape" without a need for additional acceleration. You can escape a gravitational effect without achieving escape velocity as long as you have some form of continuous propulsion providing acceleration, but the definition of escape velocity itself assumes no additional acceleration.
That selfish polluting bastard!