Sedimentary people that begin exercise regimes don't generally consume more fuel. The average American's diet is already more than sufficient - calorie wise - to fuel a bike ride. Also, those 10.6 days of longlevity achieved not only assumes the bicyclist is only likely to die of heart disease (to assume that riding a bike will usher in more healthy aspects of living would fowl the hypothesis), it also ignores the unfortunate, but inherent, risk of riding a bicycle.

This study is interesting, but there's far too many factors at work to draw those conclusions.

I'm more of an igneous person myself.

Doh!

There's a better typo in there.

Utter nonsense. The big hole: sedentary people wouldn't need to eat more. They already eat too much. The assumptions are all just plain stupid: the worst possible american processed food diet, sedentary people at dietary equilibrium, every cyclist owning a car.
When I see a *study* like this, where assumptions so obviously contradict reality, I know what I'm looking at is a junk study designed to work back from results to whatever assumptions can be cobbled together to get you there.
Utter rubbish.
FYI I actually sat down months ago and computed my own energy balances for cycling versus driving, and with my nearly vegetarian whole food diet, the net amount of greenhouse gases I'm responsible for in my commute dropped to about 1/50th of what it was on average with a car. I based my energy balances on an average of a few standard sources.

Actually, given the level of obesity in America, how can you infer they would need _more_ food? They can probably easily bike on the current food intake - in fact, if they get healthy, they probably don't have to take as many meds, they won't need to burn up all those medical resources, they might start walking to the grocery store more often, and they might even buy local produce which will mean less energy/carbon to move the food from the growing location to their mouths.

Statistically, we can't say anything about it.

Besides, where's the control group?

It seems like this study didn't account for changes in living patterns.

If one is going to cycle, one would live closer to work, closer to grocery stores, drug stores, and so on.

Factor that in, and I suspect the books balence strongly in favor of cycling.

1. This "study" comes from an organization that wants people to stay in their cars and send it money to allieviate their environmentalist guilt.

2. "Studies" claiming to compare the "true" costs of alternatives, including knock-on effects, are nearly impossible to do objectively. You can always move the comparison in the direction you want by dreaming up new kock-ons and ignoring others. For this reason, such "studies" nearly always suffer irredeemably from ideological biases.

3. Even given #2, the premise of this "study" is a doozy. If people living longer goes in the "con" column, then clearly the optimal choice is mass suicide. Most people who aren't ELF suicide bombers care about the environemnt not as an end in itself, but as a means to improving the lives of people.

the fun of science is that when you don't know what you're doing, you can just make it up! experimental design and statistics and reason are just little speed bumps.. keep at it, karl! science really can be for everyone!

David Wright: what you said.

Since I haven't read the study to evaluate the scientific merit of it, I'm not gonna chime in much further, other than to say that this quote from Kinaidos is pretty frightening:

"When I see a *study* like this, where assumptions so obviously contradict reality"

That's exactly the kind of thinking that leads to bad science -- "Look, here's how I perceive reality, so any study that contradicts that perception must be nonsense!"

Science is designed to study reality, not to confirm your perception of reality. If it's bad science, the resulting conclusions will pretty quickly be disproved when other scientists evaluate the study. If it's good science, it'll be confirmed repeatedly, whether or not it meshes with your perception of reality.

It also doesn't take into account the sterilizing effect of so much time on a bike seat. We're far less likely to procreate and clog the earth with our progeny.

Fuzzy math. That's all in theory and assumes a unique trip for each piece of food transported, which is not the case. Food is transported in bulk, and the production quantity only changes in large bulk chunks. The marginal change in consumption will not affect the supply of most stores. This argument does not hold water.

Also, by the given argument, eating more and getting fatter is also a detriment on the environment for the reasons stated. Wouldn't obesity be considered an additional environmental factor then?

This reminds me of those studies by cigarette companies that argued cigarettes were good for gov't programs because people would die before they get to use them.

This study is arguing "biking is bad because people will live longer and healthier". The fuck?

Then again, bikers have fewer biological children, due to gonad damage, homosexuality, and those weird skin tight body suits. Biking can be the solution to ALL human energy use, for all eternity.

Even if I accepted the argument that just as much gasoline is used to produce the food needed for biking versus the gasoline needed for driving - at least the pollution would be way the hell out wherever the corn and tractors are, instead of in the city where all the people are.

Of course by their logic this would also be bad, since with less pollution near them, people would live longer.

Hi folks,

I wrote the original blog post that kicked all of this off, so I thought I'd chime in with a few comments:

1) People are wrongly fixated on the food portion of this equation. The increased caloric intake of bike riders is not the dominant effect. It's the increased lifespan that matters much more.

2) David -- the study did not come from TerraPass, and Karl Ulrich has no financial stake in TerraPass. The research was done at UPenn. And for the record, we at TerraPass support increased bicycle usage. No need for bizarre conspiracy theories.

3) The study does, in fact, take into the account of increased accident risk that cyclists face.

4) The study is pro-cycling, but casts the issue as more of a public health matter than an environmental matter.

For the record, I don't happen to agree with the study's main conclusion, but, to be perfectly fair, the study's goal is to raise questions about the relationship between human longevity and the environment, which it seems to have done.

Most of the questions and objections raised here are considered in some form in the study, which is quite readable. So if you're interested, I suggest you check it out.

By the same logic, heroin users are also better for the environment. They don't eat, they don't shit, and best of all, they die young. And they're experts at recycling- they can turn any neighbor's TV into a consumable substance!

The world will be better off when we all stop riding our bikes and start using smack!

Since when am I spending $850 a month on my car? Maybe they're counting the average of all NEW financed cars. I spend way under $100, which includes the amortized cost of my piece of shit Tercel, the gas (minimal), parking (minimal), and maintenance (minimal). The lady across the street with her thrashed Celebrity wagon spends much less than I do.

And those "health benefit" studies don't usually take into account the costs of riding along next to car tailpipes or the vastly increased rate of hospital and mortuary care due to conflicts with 3,000-lb steel behemoths.

I think longevity, not bike usage, is the issue brought up here. Even the unhealthiest of us live far too long, and these are people who are the biggest drain on society relative to what they produce for it. And they're a drain for far longer than they used to be.