genec

Frankly, I think he is clueless...
https://momentummag.com/carnivorous-...rd-researcher/

Great, now factor in vegetarian cyclists, and the fact that even if a Prius only uses 8X more energy than a bike, that is still 8X more, and it still requires more road. Sheesh

Bike on my friends, this is an old and poorly supported argument.

Lemond1985

But ... Harvard ... and math formulas! There's simply no defense to those.

rseeker

One counter-argument (against that author) is that the exercise we do when biking -- or equivalent -- is necessary for our health, and should be taken as a baseline when we budget for sustainable emissions. And if we can't afford -- in terms of sustainability -- for everyone to be living healthy then there are too many of us.

livedarklions

In the comments, section, one commenter points out that to make his numbers work, you had to assume a 440 pound rider on a paleo diet vs. a Prius driver while not figuring in the carbon impact of producing the car, the batteries and disposing of same after the car's end of usefulness.

A couple of silly assumptions built into this analysis, even if you ignore the clear math errors:

He assumes people's calorie consumption closely tracks their activity levels--we have an obesity trend in this country that makes it clear that isn't the case.

He assumes that if one wasn't riding a bike, one's energy needs would diminish. One of the reasons people bike to work is it turns their commute into a fitness program. He has to assume that such people would not, if they were not biking, going to find some other way to burn those calories while exercising. I don't know about you guys, but when it's not biking season around here (New England), I spend an awful lot of time burning calories churning an elliptical machine. When I'm doing that, I'm also driving to the gym instead of just hopping on my bike and starting my routine.

genec

He makes a lot of a asumptions... such as two vegetarians in a Prius vice two Paleo cyclists... the latter which could easily be riding single file and drafting... thus using less road, and less energy.

It's a dumb argument supported by marginal assumptions and lazy math.

DrIsotope

The entire thing is based on a flawed premise from the get-go-- I'm not petite by any means, and while in full-hammer mode I burn around 50kJ/km.

On Friday, I rode 112km at a fairly brisk pace of 31.5km/hr, doing 2,304kJ of work. That's 20.6kJ/km. So on that day, a Prius would have used 20x as much energy, and a typical car 42x as much.

In simpler terms, 42 people on bikes doing 20mph use the same energy as one car. They better put a whole lot of people in that car to improve that offset.

I would imagine a bike commuter, unless conditions were particularly difficult, or they were combining their commute with a workout, might use 10-12kJ/km. So the "study" could be off by as much as factor of five.

Hoopdriver

This study seems to ignore the fact that motorists also burn food energy and produce CO2 while driving. Wouldn't you need to add that to the amounts produced by the vehicle?

In any case, the publication is prefaced with this note:

The bigger issue is that the news media may present these "findings" in a way that misrepresents reality. In this context, "may" means "yep, you better believe they will". How is the normal citizen supposed to understand these complex climate issues when sensationalism sells better than a boring presentation of reasonable thought?

wphamilton

He leaves out the emissions cost of producing the Prius, overestimates the energy cost of cycling, neglects the lowered calorie requirements of more fit and less obese individuals, and makes a dubious assumption about cyclists' diet .

debade

In addition to many of the criticisms made above, it would be interesting to consider a cradle to grave analysis. The manufacture, repairs and disposal of a car must be a big negative contributor to the environment.

JoeyBike

Don't electric cars run on Pixie dust? Or do they run on power that comes from burning fossil fuels, nuclear fission, hydroelectric, wind, or solar PRODUCED energy?

Obviously it would be more efficient to just put fossil fuels in the gas tank than burn the fuel at a remote plant to convert it to electricity (which uses energy in the process), then waste energy pumping that power miles though power lines, then have the car convert that energy into turning the wheels. Fossil fuels are darned efficient. This is why we use them.

I'm certain most of us know that nuclear power comes with a price to pay in harmful byproducts and hydroelectric dams are generally environmental nightmares that destroy rivers and natural habitats for all sorts of creatures. Windmills slice and dice migrating birds like there is no tomorrow and are regionally specific. Solar energy comes pretty close to Pixie dust and about as close to a free lunch as we can get so far, but how many electric cars are 100% powered by solar these days?

Don't even get me started on the environmental impacts of battery manufacture and disposal.

The gas-powered Geo Metro was the answer. An electric version would have been cool as well. But the American people opted for monster trucks instead. We had our chance but chose the shortest road to disaster.

Electric cars are not the answer. Fewer cars is the answer. Fewer people though ZPG (zero population growth) would be a big help to the environment as well, and a nice start to fewer motor vehicles. If we cut our emissions in half but double the population, what's the point?

Leisesturm

Oh boy, there is so much to unpack here ... your heart is in the right place, I can see that, but many of these premises are just plain wrong. It's important that they are pushed back on because if we are to really make progress we need accurate facts. 1. Fossil fuels are energy dense compared to any alternatives we have at present. Energy dense does NOT mean efficient. How much of the potential energy that can be extracted, that is the formula for 'efficient'. The theoretical maximum efficiency of an internal combustion motor is (don't quote me) ~ 20%. Actual production engines range from ~10% to ~15%. That's awful. And we have billions of them in use around the world. If we did NOTHING besides convert every single car, truck, boat, diesel locomotive, etc. to electric it would be a very, very, very, good start. A lousy electric motor would be 80% efficient. Production examples are on the road now with efficiencies in the 90% range. It is way more efficient to have a powerplant using fossil fuel than a motor vehicle. The powerplant turbine always runs at the maximum efficiency rating of the generator. A motor vehicle spends scant minutes at the speed where its efficiency is highest. There is no comparison!

Electric cars that are simply gasoline cars with electric motors are better than nothing but ... what about electric cars that are built out of composites rather than steel and aluminum? Instead of weighing 3500lbs they would weigh (empty) 700lbs! If cars were built like velomobiles using bicycle drivetrain components and bicycle based structural elements you wouldn't have to reduce the number of cars they would be a fraction of the weight, size and energy requirement. And, since you haven't noticed ... we are doing better than ZPG in the U.S. We are in negative population growth for the first time ever and not for any good reason. We've never had so many Americans in the 30 - 50 age group killing themselves in recorded history and that's just one reason. There is zero danger of the population doubling and a much greater chance for a catastrophic population crash going forward. Still, if the overall attitudes towards birth control and sex education remain mired in the Victorian Era ... ... The present administration has de-funded any aid organizations operating in the Third World that do not promote an abstinence only birth control protocol. Individually most people want everyone to behave themselves and stop having sex. They want less people around, not more. This freaks out the ruling class because as it is every day there are fewer and fewer people buying gasoline, cars, car accessories, car insurance ... ... they want more people around, not less. It's over my pay grade to resolve but it doesn't appear that the average guy understands what they are dealing with. Things are the way they are because people much more powerful and influential than you are WANT them that way. Did someone say /thread?

tyrion

How many cyclists "consume mostly meat"? My guess is that people that eat mostly meat don't cycle much.

And I didn't dig into it much, but does the study account for the Prius driver's diet? What if the Prius driver eats mostly meat?

tyrion

Exactly. It's a gift to those that want to propagate misinformation. Coming soon to Fox News:

Harvard Study Indicates Gasoline Powered Cars Better for Environment than Bicycling

indyfabz

One more reason I am glad I went to Penn, not Harvard.

mcours2006

I've seen this a few years back. Pretty silly stuff.

What about the energy used to extract the fuel from the ground in the first place? Oil sands? What about refining it? Transporting it? Environment impact of pipelines, development, roads, etc. in addition to the manufacturing cost of the vehicles in the first place?

We should just all grow our own vegetables in the backyard of our mini-house or balcony of our mini-condo, and find a job that's within walking distance of said condo/house.

I-Like-To-Bike

You must have been reading the LCF - Save the World mantra, proselytizing asceticism on the LCF list by a few "critical thinkers".

mcours2006

You caught me!

Aubergine 

Maelochs

As far as I know an internal combustion is about 33 percent efficient, with the loss being mostly heat. From what I have heard, electric cars In Operation are still using less fossil fuel than a gasoline-powered car. However, those batteries .....

As for the topic of the OP ... I refuse to even acknowledge it further than this. i do not deliberately step in dog waste while walking .... or browsing the internet.

mcours2006

Party pooper..

Hoopdriver

The tactic of presenting preliminary studies to the media before doing real research is becoming more and more common. The objective is to cause a stir (panic if they are lucky) that precipitates additional research funding. "Shaking the money tree" is another way to describe it. This behaviour is not as bad as falsifying research to get more funding, but it's just a few steps away.

mr_bill

venturi95

It sounds like study funded by the fossil fuel industry. I don' t think I have ever seen such a great example of what science calls "cherry picking data". A truly steaming pile of horse manure. Doesn't matter anyway, the only level of technology that is truly sustainable is stone age technology.

JoeyBike

True dat.

79pmooney

But only at a radically smaller population. Of course, if we reverted to stone age technologies, that would sort out fast (in Earth time; say two or three generations. It wouldn't be pretty.)

Ben