David HoA person on a bicycle is by far the most energy-efficient among animals and machines per distance traveled relative to body weight. The bicycle is magic.
Karl Urban@davidho and the person even uses very little exosomatic energy compared to other machines in this plot.
Janne@pikarl @davidho in practice the energy use is still non-negligible and should be accounted for in planning. Especially the energy should be derived from plant matter...
https://www.nature.com/articles/s41598-020-66170-y
Bicycle is still a magical invention!
Fuelling walking and cycling: human powered locomotion is associated with non-negligible greenhouse gas emissions - Scientific Reports
Reducing motorized transport and increasing active transport (i.e. transport by walking, cycling and other active modes) may reduce greenhouse gas (GHG) emissions and improve health. But, active modes of transport are not zero emitters. We aimed to quantify GHG emissions from food production required to fuel extra physical activity for walking and cycling. We estimate the emissions (in kgCO2e) per kilometre travelled for walking and cycling from energy intake required to compensate for increased energy expenditure, and data on food-related GHG emissions. We assume that persons who shift from passive modes of transport (e.g. driving) have increased energy expenditure that may be compensated with increased food consumption. The GHG emissions associated with food intake required to fuel a kilometre of walking range between 0.05 kgCO2e/km in the least economically developed countries to 0.26 kgCO2e/km in the most economically developed countries. Emissions for cycling are approximately half those of walking. Emissions from food required for walking and cycling are not negligible in economically developed countries which have high dietary-related emissions. There is high uncertainty about the actual emissions associated with walking and cycling, and high variability based on country economic development. Our study highlights the need to consider emissions from other sectors when estimating net-emissions impacts from transport interventions.
@janvenetor wait, walking / cycling is in the range of 200g CO2/km/person?! This is the value for flying as well. Can this be right?@davidho
Martin Stengel@pikarl @janvenetor @davidho It obviously is. But not from fossil sources and not up in the atmosphere and not 800 km in 2h.
@mstengel that's the interesting question which I do not see in this paper. I'd expect fertilizers or diesel for tractors indeed being fossil fuels which end up in the atmosphere (as CO2 or laughing gas). Same for direct emission from farm animals (especially methane). Indirectly also from pasture plants on areas of former rainforrests or swamp land which has an "emissions tag" into the atmosphere. 1/2
Of course non-animal nutrition might nullify this. But for an average western meat-based nutrition it seems to me that "biking 2000km a year" vs. "making a long-range flight" can be equivalent for the climate.
Correct me, please. 2/2
@pikarl @mstengel @davidho the range of uncertainty is very large, but if you eat half of all that locomotive energy extra in UK or Australian diet...
This serves mostly to highlight the cost of even one flight, and our dietary choices, though.
Cycling all year around is still magical in every other respect.
Solar🌄Garden@janvenetor @pikarl @mstengel @davidho
Personal anecdotal evidence for #eBike more efficient than pedal-alone: regular 40km shopping trip on eBike often undertaken without /much/ extra food, indeed often set off with just coffee.
However, motor [gear] failure half-way to the collection resulted in return from the breakdown place - a long slow mountainous pedal home. Over the next few hours, I ate about 3 extra energy-rich meals before my hunger was satisfied, at least a normal day's /extra/ food!
The eBike typically consumes about 1 kW.hr on the return trip. Load complicates potential calc, of course.
@pikarl @janvenetor @davidho And this nice consideration quickly starts to falter when the passenger who forgoes the bike for climate protection reasons ;-) then finds his way to the gym or the running track for health reasons and puts in the same amount of energy there without getting off the ground, while the cyclist has already done this on his everyday commute.
Lydia Trivia@pikarl @mstengel @janvenetor @davidho I've wondered about this and I concluded:
1. the carbon is coming from plants (maybe via fungi and meat animals) and therefore came out of the atmosphere shortly before
2. we use energy even at rest, even while sitting in a car or on a plane
3. we need to do exercise to stay healthy anyway
1. the carbon is coming from plants (maybe via fungi and meat animals) and therefore came out of the atmosphere shortly before
2. we use energy even at rest, even while sitting in a car or on a plane
3. we need to do exercise to stay healthy anyway
@lydiafacts thanks. Certainly the "magic parts" of cycling are true, like physical wellbeing etc.
But for the agriculture there are critical ressources in use which are not all fuels but certainly fossil. Like phosphorous which is mined. And like nitrogen which is mostly produced via the Haber Bosch process using "natural" (fossil) gas.
Those are not at all reasons to stop cycling but to think of sustainable living with a systems view.
Magnus Ahltorp@pikarl @mstengel @janvenetor @davidho Are you saying the first diagram is incorrect? Because according to that, even counting per gross weight, “man on bicycle” is far more effective. If you only count payload, the airplane is even less efficient.
@pikarl @janvenetor @davidho You're right with this indirect view, there are fossil componets due to the way we source our nutrition. This coincides with the huge variation over different stages of economic development. And yes, Methane is a huge lever in climate questions (though not fossil).
jaseg@pikarl @janvenetor @davidho There are some very large error bars on these numbers, primarily because the base data they used for the assumption that people who walk more also eat more had very imprecise results. Also this assumes an average non-vegetarian diet, which is vastly more greenhouse gas intensive compared to other options.
@pikarl @janvenetor @davidho A fun tidbit I just found out: The reduction in total life-cycle greenhouse gas emissions for switching from a meat-based to a vegan diet is in proportion roughly equal to what you get switching from a gas car to an EV.
Ramin HonaryA person on a bicycle is by far the most energy-efficient among animals and machines per distance traveled relative to body weight. The bicycle is magic.
@davidho I don’t think that chart accounts for the energy cost of building the roads over which we ride our bicycles. We can’t easily cycle of sand, grass, or mud. We at least need gravel, and probably concrete. And concrete is one of the most carbon-intensive materials to make.
Once that initial energy cost is paid, that cost can be divided across many individual cyclists and divided across many years of use. The more people who use the road, and the longer they use it, the lower the total energy cost per individual. This just goes to show how important good city planning is for reducing our carbon footprint.
@jaseg Thanks for this pun 💚. I'd appreciate more research in life-long cycling life-cycle research. 🚴🏾 @janvenetor @davidho
AL@jaseg @pikarl @janvenetor @davidho
found out where?
The provenance of the data is important in todays world.
jer@jaseg @pikarl @janvenetor @davidho
I guess it's a good analogy, but it wouldn't work for anyone who happens to not be concurrently considering exactly those two life choices. 😃
draeath@pikarl @janvenetor @davidho humans are very well adapted to "outwalking" prey, apparently. Stalk, spook, and repeat. Eventually the thing can't run away anymore. That's not a very quick process, however. Note the graph doesn't include speed as a variable.