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I suspect what your colleague is getting at is that the repeated slowing down and speeding up creates more emissions than just driving along at a constant speed. Very true, it does.
But who is "making" his car overtake cyclists? Does the person on the bike have a gun to his head? He doesn't have to overtake anyone. Nor does anyone else in a car.
Driving smoothly is a great way to reduce emissions. Ultimately if there's cyclists about and vehicle drivers are feeling precious about the environment, they should be driving at the same speed as the cyclist and not overtake anyone. This smooth driving would create less emissions, and if everyone did it, perhaps it might also ease congestion at the usual choke points.
Its all the ****ing cars coming the other way that are the issue not the ****ing bike!!!
"Last Sunday I rode fairly locally… and as I keep an eye on consumption etc. I noticed that being behind cyclists does decrease my consumption"#
you has a MPG ometer on your bicycles .... WANT !
Who assumes? The person who stated the thread asking about it? hmm. yeah, long ramble, much bollocks.
You assume most of this persons journey and the rest of the people who are also commuting is 0-10mph.... how do you know that?
You assume cycling is somehow less environmentally polluting but in what way, under which conditions, locally or globally, NoX vs CO2 and methane?
It seems you start off with an assumption that cycling is environmentally better but don't seem to want to actually define in what ways and how... that assumption may or may not be correct but you only seem open to the factoids that support your assumption.
hmm. yeah, long ramble, much bollocks.
Yeah, long ramble... because I don't simply assume what appears on the face of it.
The real question is really do you give a shit for the environment at all or do you just want to cycle on your terms???
If the facts were all gathered and presented and proved that cycling is actually less environmentally friendly would you stop or choose to ignore them?
To be honest, I'd support you deciding you want to cycle anyway but at least having recognised the impact.
Like I say, I CHOOSE to drive 100 miles each way to trails most weekends... I try and minimise the impact but it would seem on the face of it I could cycle 10 miles each way and that would probably be better for the environment but I'll do it anyway.
TINAS – you’ve not accounted for upstream emissions from extraction, processing and distribution for petrol
I've not cooked the potato either.
But for completeness that's about 0.66kgCO2/l
So swapping 2.3 kgCO2/l for 2.96kgCO2/l gives about 54kgCO2 for150miles of car commuting.
Vs 29kg for the bike (plus an unknown amount in cooking the food)
OTOH if the bike was fueled by chocolate (~4.5gCO2/g) then the CO2 emissions drop to about 7 kgCO2. Mmmmmmmmm chocolate.
Obviously that takes no account of the health benefits of cycling, or the harm to health done by NOx and particulates or the harm to society by taking up towns and cities with cars. But interesting to see that on greenhouse gas emissions alone the bike and a healthy diet isn't that great. But 30kg/week is still almost a ton and a half of CO2 over a year.
"You assume cycling is somehow less environmentally polluting but in what way, under which conditions, locally or globally, NoX vs CO2 and methane?"
strange arguement - bike takes less energy to produce than a car. uses less energy in use than a car , emits nothing compared to a car , takes up less space than a car , doesnt leave behind the eyesore of a parked car taking up space that cannot be used for anything else.
its not simply use a bike or nothing. there is walking , theres communal transport , there are Assisted bikes , hell id even go as far as to include the humble moped in the alternatives as most of the above apply.
but simply put peoples lives have evolved to be complicated largely by choice that they cannot see any other way but the car to get around incase they make the occasional trip to wickes.
while ill never get to power with a policy of banning the car from city centers ala brugge and gent its the way forward 😉 the propultion of the vehicle isn't the problem is the vehicle its self.
You assume cycling is somehow less environmentally polluting but in what way, under which conditions, locally or globally, NoX vs CO2 and methane?
Under absolutely anyway you want to measure it. Moving 100kg of bike and rider is always going to be less polluting then moving 1500kg+ of car and driver. It's blindingly obvious to anyone who even thinks about it a little bit
Under absolutely anyway you want to measure it. Moving 100kg of bike and rider is always going to be less polluting then moving 1500kg+ of car and driver. It’s blindingly obvious to anyone who even thinks about it a little bit
Check my maths up there.
Assuming you eat only potatoes your CO2 emissions are halved.
Eat just 140g of beef a day and you're writing off 150miles a week of cycling benefit of greenhouse gas emissions.
So you calculated the CO2 cost of providing fuel for humans but not of providing fuel for cars?
Hmmm...
Right enough I'll check my maths
because people driving cars dont eat at all ,looking at the growing waist line of the general populous it seems the eat as if they were cycling anyway.
Your maths is skewed because people who ride bikes need about 2000 Cals per day and drivers need that too even though they aren't exercising
You assume most of this persons journey and the rest of the people who are also commuting is 0-10mph…. how do you know that?
It's a really well researched statistic that comes out in all the electric car threads, shortly followed by somebody claiming they drive 400 miles a day every day and that there is no way anybody does short journeys.
Also if your going to wicks that much you should probably get stuff delivered in one lot and finish building the house!
Now Strava tells me I burn ~2000-3000 calories per day of cycling, so about 7500 per week. Or in food terms about 10 kg of potatoes.
Your assumption is based on you only consuming the exact amount of calories needed to survive the rest of the time and the calorie estimate on strava being accurate. That and you buying exactly the right amount of food and wasting nothing.
The intake for a TdF stage is estimated to be between 4-6000, how much extra are you consuming when you cycle? How much comes from your regular food.
strava told me i burnt 3000 calories last night riding 11k and climbing 600m.
Definitely accurate.
ah i see edits borked again.
just to add - your average 24hour racer must fade away to nothing at the end of every race if stravas to be believed !
People who work at home are the real menace. Think how much quicker everyone could drive to work if all the buildings were flattened, and you could drive in a straight line to work. Get everyone to sleep in tents… take the tents down at 7am… anyone having a lie in, and then making me slow down and deviate around their tent, gets fined for my excess fuel used.
strava told me i burnt 3000 calories last night riding 11k and climbing 600m.
Definitely accurate.
<span style="font-size: 0.8rem;">Your stats may be borked, but 2500 calories in 4 hours/50miles of riding doesn't sound too optimistic.</span>
because people driving cars dont eat at all ,looking at the growing waist line of the general populous it seems the eat as if they were cycling anyway.
I considered it, but as I'm alive for the other 20 non-cycling hours and a BMR is around 150cal/hour it barely figured (I'm either driving for 1 hour and sat on the sofa for an hour, or riding for 2 each way) , say 10% of the cycling figure, 2.9kg CO2/week.
So you calculated the CO2 cost of providing fuel for humans but not of providing fuel for cars?
Hmmm…
I did, petrol converts to 2.3kg of CO2 when burnt. A further 0.66kg is emitted during it's processing, hence the total figure I used of 2.96kgCO2/l of petrol.
Your assumption is based on you only consuming the exact amount of calories needed to survive the rest of the time and the calorie estimate on strava being accurate. That and you buying exactly the right amount of food and wasting nothing.
That assumption applies to both the driver and cyclist.
And 1250 calories for 25 miles on the mountainbike, if anything I think that's probably pessimistic! This morning STRAVA said 1485, which is more usual, but on road bike days it's lower.
how much extra are you consuming when you cycle? How much comes from your regular food.
Not 10kg of extra potatoes as I'm trying to lose weight. Lets assume those 10kg of potatoes were consumed at some earlier point this year, probably absorbed fairly inefficiently and stored efficiently as fat. So it's probably a lot more than 10kg of potatoes.
For the sake of clarity, potatoes were the most calories per kg of CO2 I could find for stuff that would be considered carbs and therefore fuel. So my actual diet is probably much much worse in terms of CO2 emissions.
My conclusions was cycling halves your CO2 emissions if you only eat stuff that's good for you.
just to add – your average 24hour racer must fade away to nothing at the end of every race if stravas to be believed !
Why do you think that?
90g of carbs and hour = 360 calories. Say 50:50 carbs/stored fat burnt makes that 720/hour, total fat burnt ~1.2kg in 24h.
A bit more than I'm allowing for actually but then I'm not racing (dunno how brisk 2h commuting pace compares to 24h pace, probably not far off).
And from the OP
(if somewhat blinkered)
Let's be honest, we want cycling to be good!
inventor/scientist/boffin type
Often means - I have formed a view at an early age and this will never change... I am right and the world needs to bend to me...
Bear in mind though that a lot of people eat just as much as a cyclist would, but don't cycle. That should also be taken into account in the calculations 🙂
“You assume cycling is somehow less environmentally polluting but in what way, under which conditions, locally or globally, NoX vs CO2 and methane?”
strange arguement – bike takes less energy to produce than a car. uses less energy in use than a car , emits nothing compared to a car , takes up less space than a car , doesnt leave behind the eyesore of a parked car taking up space that cannot be used for anything else.
Energy is part of the equation ... however what is the bike made of (where and what types of pollution)? What is the expected lifetime?
A bike does emit in the same way as a car.... the engine emits CO2 and methane...
Richmtb: Under absolutely anyway you want to measure it. Moving 100kg of bike and rider is always going to be less polluting then moving 1500kg+ of car and driver. It’s blindingly obvious to anyone who even thinks about it a little bit
Why ??? It might seem obvious but is a 10 ton tram running on some clean (nuclear) electricity or hydrogen cell more polluting than a car???
its not simply use a bike or nothing. there is walking , theres communal transport , there are Assisted bikes , hell id even go as far as to include the humble moped in the alternatives as most of the above apply.
but simply put peoples lives have evolved to be complicated largely by choice that they cannot see any other way but the car to get around incase they make the occasional trip to wickes.
Agreed .... in part.
I mostly don't use the car for work... but sometimes I do.... and I won't know until last minute.
Bez: You might want to read the <span class="bbcode-strong">thread title</span> again before you go wibbling on about shopping in Wickes <span class="bbcode-strong">etc</span>.
Except I have the car anyway.... either as Mike say's in case I go to Wickes or because I sometimes need to drive to work or for the most part because I can stick bikes in it!
Mikewsmith: Also if your going to wicks that much you should probably get stuff delivered in one lot and finish building the house!
Well, that means not cycling and finishing building 😀 ... (not to mention they always pick the crap to deliver and I prefer selecting myself than getting bent joists or warped ply with the corners chipped). Most of my stops at Wickes now though are because it's right on the route back from trails to my house...
Mikewsmith: It’s a really well researched statistic that comes out in all the electric car threads, shortly followed by somebody claiming they drive 400 miles a day every day and that there is no way anybody does short journeys.
I suspect it's somewhere in-between... and strongly on how you define it.
I know plenty of people are just lazy but I'd never commute at 0-10 mph for most of the time unless work really forced me to. I've lived and worked in lots of places and from experience anywhere that most of your time is spent 0-10 in a car there are simply easier ways to travel... (let alone that usually means parking is going to be a nightmare)
I'm being a pit nit picking perhaps but also that's not the same as saying most car journeys are short distances or someone is "commuting". It's all in definitions... my friend (who Ive been messaging this morning) for example make a car short journey each morning for his commute... his wife drops him at the station, then drops off the kids at school then drives 20-30 miles to her work.
You could count his "commute/car journey" ... ? or not ... it all depends what someone is trying to prove.
Is he lazy ??? (He's a triathlete so I'd say no in terms of exercise but perhaps yes in terms of spending time with his family is more important than running to the station ?)
Anyway regardless... that doesn't mean this to other affected commuters behind Bez are driving 0-10mpf for most of the time nor take into account it's not simply the car immediately behind it's a whole queue of cars.
thisisnotaspoon:
Let’s be honest, we want cycling to be good!
That's my point and for some, regardless of how much you calculate they will ignore it... I don't know any single answer nor any complete way to measure environmental impact..just to illustrate hat is the difference in environmental impact from potato fuelled vs chocolate? How do you measure that?
I drive 200 miles to/from my preferred trails... I'm going to keep doing it. I'm being honest.
I'm not going to sanctimoniously claim its for any other reason than I like going there to cycle... if I didn't I'd have finished the bloody house by now!
molgrips: Bear in mind though that a lot of people eat just as much as a cyclist would, but don’t cycle. That should also be taken into account in the calculations
No it shouldn't (probably*) because they are going to eat that anyway... whereas the cyclist is eating extra.
*outside of commuting but I guess an exception is cycling to get your food rather than driving?
Good analysis TINAS.
As ever, the old saying "it's a bit more complicated than that" keeps popping into mind. Humans aren't particularly effiencent in turning input energy into bike powering energy - 25%? I can't be bothered to look it up, but we generate a lot of heat to create the output force.
What's the overall efficiency of a car, in terms of stored energy in the petrol/diesel being converted to kinetic energy of the car?
(let alone that usually means parking is going to be a nightmare)
The solutions are so simple! Knock down all places of work… offices, shops, factories etc… bingo… enough room for parking for EVERYONE to drive to work.
Anything that gets in the way of me driving to work, at a constant speed, in the most direct fashion, must be removed.
Humans aren’t particularly effiencent in turning input energy into bike powering energy – 25%? I can’t be bothered to look it up, but we generate a lot of heat to create the output force.
Fortunately the exercise also gives benefits to the individual, long term it may prolong life which is bad for the environment
But honestly driving a car with 1 passenger is a crap use of resources
I don’t know who this bloke is or what his commute is but I VERY rarely do 0-10mph…. for any significant time.
Get one of those driving apps that measures average speed, time stationary, time within certain speed ranges etc. I think you'll be very surprised at how bad it actually is!
My commute if I do it by car is 15 miles and involves 6 miles of motorway. Even travelling relatively early in the morning it's rare to do it in under 40 minutes, an average speed of 22.5mph. It can take over an hour.
In the morning, the motorway is always free-flowing at that time - let's call it 60mph to make the maths easy, 6 minutes so it stands to reason that the remaining 11 miles in 34 minutes involves an awful lot of very slow / stationary time even though it's all suburban A and B roads.
If I ride, it's 16 miles and I can do it in an hour. Every time. 16mph average vs 22.5mph in the car. I imagine the difference would be even less if I drove the same route as I ride (which I can't as it involves a couple of segregated / back street cycle lanes).
@mikewsmith Gut feel tells me the same, and I always feel better for bike commuting rather than driving... but I also like a solid numerical argument.
Well a 10mile commute here, 45mins and 450 starve calories each way. Food intake about the same as normal.
40 min drive option 10-15 miles
40 min tram ride
The drive will mostly be spent stop start being held up by bloody cars and traffic lights and the only real hold ups on the bike commute are cars
so do I, but this is just a load of numbers pulled out of someone’s arse to support a totally ludicrous proposition!but I also like a solid numerical argument.
A bike does emit in the same way as a car…. the engine emits CO2 and methane…
Are you talking about driverless cars?
just to illustrate hat is the difference in environmental impact from potato fuelled vs chocolate? How do you measure that?
Potatoes
770cal/kg
2.9kgco2/kg
265 calories per kg co2.
Chocolate
5000 cal/kg
Between 1.1 and 8.5 kgco2/kg depending on brand
Assuming 5 as a sort of average then 1000 calories per kg. So eating chocolate as fuel is environmentally better, presumably because its energy dense and easy to transport.
so do I, but this is just a load of numbers pulled out of someone’s arse to support a totally ludicrous proposition!
If that's referring to me. Then no, they were all googled except where I stated an assumption.
I asked did anyone want to check my working and numbers because I was as surprised as anyone that cycling was barely 50% better than a car (and a not particularly efficient car at that).
I could have use<span style="font-size: 0.8rem;">d different numbers, my commute home today was an estimated 1750 calories, over a third more than I allowed for.</span>
I could have used the manufacturer figure of 100g co2/km (mine works out around 300).
If I had done that then I think cycling wouldn't come out on top? But that would be stretching the assumptions a bit far (we know Strava is probably optimistic as are car emissions in the other direction).
Here's a comparison chart of energy costs for different methods of transport:
https://www.exploratorium.edu/cycling/humanpower1.html
Unless your inventor/scientist/skeptic is using an electric car then his 10 minute journeys are the worst of all
(With or without his curiously synchronised cyclist impeding progress)
Latest stats from Emissions Analytics show that the time spent in a car to cover these short distances - especially in urban areas - are not sufficient for a vehicle’s pollution control system to warm up and become fully functional.
After reviewing a number of new models last year, it found that it can take more than five minutes for pollution control systems to reach operating temperatures, thus allowing harmful nitrogen oxides (NOx) to be emitted into the air and the car's cabin.
While diesel cars have a much higher NOx output, proportionally it is petrol cars that perform worse in the first minutes of driving, the study showed.
It means that for a journey of five miles covered at an average speed of 30mph, half of the 10 minute trip would have exposed the car occupants to these higher pollution levels.
Licky for us all that most peopel mKe such short journeys by other means than car? Oh...
so do I, but this is just a load of numbers pulled out of someone’s arse to support a totally ludicrous proposition!
This, in spades!!!
But Malvern rider what if the horse rider being chased by a swimmer needs to go to Wickes to pick up a piece of plasterboard ?
But Malvern rider what if the horse rider being chased by a swimmer needs to go to Wickes to pick up a piece of plasterboard ?
What kind of horse? How frequent are these journeys? Can we call them a journey at all?
😆 @ Trail_rat!
The 1-10mph thing is because I work at the same place as the scientist twonk and so I kind of am able to assume in a blinkered way which roads he uses. Like, it's one of the bloody reasons I cycle. For my own benefit.
@Stevextc - I'd like to suggest you find a more succinct/edited/condensed way to express yourself on the forum, cos I don't know about anyone else, but I really can't be bothered to read a whole one! so I might miss I vital piece of information.
All I know is Steve goes to Wickes alot and he drives 200 miles to ride a bike. Nothing else went in.
Motorists hate us because they look out of their box and see our fantastic legs,its that simple.
I'm struggling to understand why there is even any debate about this.
Stop start driving is problem caused by drivers of motor vehicles collectively not driving progressively.
My old Volvo did 19 to the gallon driving it how I liked, in town and I did a prolonged experiment of accelerating very steadily, coasting where possible and anticipating when I'd need to brake so I'd coast rather than brake and therfore not accelerate as much to get back up to 30mph and I got the fuel efficiency up to about 25mpg average town driving.
Granted its a big engine but it's a huge percentage saving in fuel efficiency.
The conclusion is clear, cyclists don't cause drivers of motorised vehicles to emit more pollution, drivers of motorised vehicles who don't or won't drive progressively, don't use anticipation or use their gearboxes inefficiently cause more pollution.
Stop start driving is problem caused by drivers of motor vehicles collectively not driving progressively.
& I agree to a large extent. The amount of times I have to actually stop at a roundabout cos the divvy in front doesn't/can't read the road is unbelievable. It's not hard is it? Watch the roundabout & see who's doing what FFS!
It all mounts up.
If he drives for 10mins the car will be running rich as its not warmed up fully , so maybe 20mpg average.
10 min drive is probably 4 - 5 miles given the locality and time of day .
Why does he not buy an E-bike ? His commute would be almost identical in time.
Ah, now, you're assuming he has some desire to change his commuting ways.. I believe the only desire he has is for the pesky cyclists to get out of HIS WAY.
What if we all commuted by skateboarding? Would the extra calories needed from potatoes plus the added strain on the NHS mean it would be worse than driving ten miles in a steam engine?
Would the extra calories needed from potatoes
I thought we were not allowed to eat potatoes these days because they were too complicated, or was it because they were clever can't remember. Do potatoes have feelings?
Ah, now, you’re assuming he has some desire to change his commuting ways.. I believe the only desire he has is for the pesky cyclists to get out of HIS WAY.
Exactly, the environmental thing is just a smokescreen (probably caused by accelerating around cyclists...). Just like when people say they want cyclists off the roads, or to have to wear hi-viz all the time, or not be allowed on main roads, or be forced to ride no more than 3cm from the kerb. They'll say "I've nothing against cyclists, I just want them to be safer" and yet they never petition for new kerb-protected cycle lanes or 5 yearly retests or tougher penalties for bad drivers, in fact they'd probably petition AGAINST all those things that actually would make the roads safer.
Anyone who's so concerned about his or her environmental footprint that they're moaning online about having accelerate around a cyclist shouldn't be driving a car anyway. If he likes driving his car and just doesn't want to slow down for 5 seconds when he meets a cyclist then he should be brave enough to just say that, not pretend that he's an ecowarrior trying to save the planet.
Potatoes have feelings but they are going through counselling, they are unsure whether they are simple or complicated.
Don't ask them, or you may trigger an existential crisis..
Long story short, if you eat enough meat the extra calories burned by biking can lead to similar emissions as driving a car with good fuel economy
https://keith.seas.harvard.edu/blog/climate-impacts-biking-vs-driving
Seems to have a fair bit of similar information to that of TINAS. You could say you're a vegan....