TonyR wrote:You are forgetting the very high carbon footprint of agriculture (fertilizer, farm vehicles etc), the processing and transportation of the resultant food and the cooking of it when you get it home. Those are all mainly fossil fuel based activities. You can readily estimate that a person on an Atkins diet (lots of meat) has a fossil carbon output per mile that exceeds that of the average family car.
Does this estimate for the average family car's footprint include the driver's food footprint. And the passengers' plus the petrol station attendant's food, the tanker driver's food, the food of the assembly line workers, the food of the iron ore miners etc.etc.?
All this presumes people in cars don't eat. If they do, they may burn less Existential fuel than a cyclist but they will burn it.
nez dans le guidon wrote:All this presumes people in cars don't eat. If they do, they may burn less Existential fuel than a cyclist but they will burn it.
If you burn up more calories by cycling then you will need to replace them with eating or drinking. In a car it takes far fewer calories to move from A to B.
TonyR wrote:If you burn up more calories by cycling then you will need to replace them with eating or drinking. In a car it takes far fewer calories to move from A to B.
Of course it would probably good for the driver's health to use up more calories.
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
TonyR wrote:If you burn up more calories by cycling then you will need to replace them with eating or drinking. In a car it takes far fewer calories to move from A to B.
Of course it would probably good for the driver's health to use up more calories.
The problem is not that people who cycle (or walk or run) eat more but that people who don't cycle/walk/run continue to eat more.
I already eat more than I need because I live in a Western country with abundant food (and I am at the poorest end of the nation's spectrum). In the years when I was doing 7,000 miles, mostly in hilly areas, I still didnt lose enough weight.
People are already eating enough in the UK that any potential extra emissions due to cycling food were emitted anyway.
I dont know about that as it isnt part of my lifestyle.
I just try and get my regular meals, even on an Audax. If I eat five meals a day on a very long Audax that is because I am staying awake, if I was staying awake at home I would still be snacking every so many hours if I wasnt sleeping.
For commuting to and from work, over a normal distance, yes it is all bunkum.
Mark1978 wrote:But your emissions from riding will come from food, most of which is in the form of atmospherically fixed carbon into plants, some of which is fuel for the food manufacturing process.
You are forgetting the very high carbon footprint of agriculture (fertilizer, farm vehicles etc), the processing and transportation of the resultant food and the cooking of it when you get it home. Those are all mainly fossil fuel based activities. You can readily estimate that a person on an Atkins diet (lots of meat) has a fossil carbon output per mile that exceeds that of the average family car.
I dont eat meat and welcome any chance to promote the vegetarians' benefits to the greater world good but I find this a bit hard to believe, even for such an extreme case as the Atkin's diet.
My stinky diesel can (quite literally) do about 13 miles on a litre of veg oil. I think that would power a cyclist a lot, lot further than 13miles. Obviously we can not live on veg oil alone but it was something that both a human and a car can convert to motive force (ie fuel).
meic wrote:I dont eat meat and welcome any chance to promote the vegetarians' benefits to the greater world good but I find this a bit hard to believe, even for such an extreme case as the Atkin's diet.
My stinky diesel can (quite literally) do about 13 miles on a litre of veg oil. I think that would power a cyclist a lot, lot further than 13miles. Obviously we can not live on veg oil alone but it was something that both a human and a car can convert to motive force (ie fuel).
The carbon footprint of beef, thanks to its carbon intensive production methods, is 13kg per kg and butter is even worse at 24kg per kg. If your 13 miles were done on fossil fuel in an average car it would produce about 2.5kg of CO2. If you did 13 miles cycling on beef its about 2.5kJ of energy consumed which at 1.3kJ/100g for beef is 200g of beef with a carbon footprint of 2.6kg. So cycling powered by beef has about the same carbon footprint as an average car while its about twice the average Class A car. A butter powered cyclist is even worse. QED.
meic wrote:I dont eat meat and welcome any chance to promote the vegetarians' benefits to the greater world good but I find this a bit hard to believe, even for such an extreme case as the Atkin's diet.
My stinky diesel can (quite literally) do about 13 miles on a litre of veg oil. I think that would power a cyclist a lot, lot further than 13miles. Obviously we can not live on veg oil alone but it was something that both a human and a car can convert to motive force (ie fuel).
The carbon footprint of beef, thanks to its carbon intensive production methods, is 13kg per kg and butter is even worse at 24kg per kg. If your 13 miles were done on fossil fuel in an average car it would produce about 2.5kg of CO2. If you did 13 miles cycling on beef its about 2.5kJ of energy consumed which at 1.3kJ/100g for beef is 200g of beef with a carbon footprint of 2.6kg. So cycling powered by beef has about the same carbon footprint as an average car while its about twice the average Class A car. A butter powered cyclist is even worse. QED.
Your maths implies that you have a requirement of 100g of butter to cycle 13 miles. I dont believe that either or I could theoretically shift a Kg of "belly pork" by riding a 200K Audax.
meic wrote:Your maths implies that you have a requirement of 100g of butter to cycle 13 miles. I dont believe that either or I could theoretically shift a Kg of "belly pork" by riding a 200K Audax.
All reputable data whether you believe it or not. Of course if you know better perhaps you would share your source. "I don't believe it" is not generally accepted as proof.
meic wrote:Your maths implies that you have a requirement of 100g of butter to cycle 13 miles. I dont believe that either or I could theoretically shift a Kg of "belly pork" by riding a 200K Audax.
All reputable data whether you believe it or not. Of course if you know better perhaps you would share your source. "I don't believe it" is not generally accepted as proof.
I now nothing about the subject, but if a person rode 200K without eating or drinking would they be 1Kg lighter?
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
I'm no expert but I know this bit. You can't metabolise either from your liver or stored fat to ride 200k. You have to eat /take on glucose. So no losing kg in a simple ride.
meic wrote:I dont eat meat and welcome any chance to promote the vegetarians' benefits to the greater world good but I find this a bit hard to believe, even for such an extreme case as the Atkin's diet.
My stinky diesel can (quite literally) do about 13 miles on a litre of veg oil. I think that would power a cyclist a lot, lot further than 13miles. Obviously we can not live on veg oil alone but it was something that both a human and a car can convert to motive force (ie fuel).
The carbon footprint of beef, thanks to its carbon intensive production methods, is 13kg per kg and butter is even worse at 24kg per kg. If your 13 miles were done on fossil fuel in an average car it would produce about 2.5kg of CO2. If you did 13 miles cycling on beef its about 2.5kJ of energy consumed which at 1.3kJ/100g for beef is 200g of beef with a carbon footprint of 2.6kg. So cycling powered by beef has about the same carbon footprint as an average car while its about twice the average Class A car. A butter powered cyclist is even worse. QED.
I think those kJ should be MJ. Sorry to be pedantic.
