More Analysis of the Environmental Impact of Walking vs. Driving

Last month I blogged about Chris Goodall‘s claim that walking could exacerbate global warming more than driving if the person doing the walking gets his or her calories from foods like beef or milk.

A group called the Pacific Institute has done some further analysis of the data. Their analysis suggests that for most reasonable assumptions about the diet of the walker, driving generates a greater carbon footprint.

I like how the Pacific Institute approached this issue. They used data and clearly articulated assumptions to better understand these claims. They put everything out on the internet so that people can check what they have done and challenge it if appropriate.

The A.F.L.-C.I.O. might take a lesson from this.


Subsequent to this question has any data been put forward and analysed as to the effects of the carbon footprint of the new hybrid cars Vs the traditional engines used today (petrol or diesel). I'm not referring to the immediate effects but rather the long-term effect, as I believe that the storage cells are more detrimental to the environment than the emissions emitted from the traditional engines.


189lb person, 2673 calorie diet? This is America people, shouldn't that be 245lb person and 5000 calorie diet? I'm sure if we spent more time walking or biking we might slim down though.


#1. speaking of someone who uses a lawnmower and (for a time) a robot vacuum cleaner and also drives to the gym and runs on a treadmill...

a. Pushing a reel mower or even a gas mower does not help me improve my speed in foot races or triathlons.
b. When I run on the treadmill, I can listen to music, I can think about interesting problems, I don't have to concentrate on where my feet are, or if there are rocks/balls/sticks ahead. I can multitask in ways that I can't when I'm mowing.
c. Mowing takes between 30 minutes and 1 1/2 hours per week, depending, and I can only do it during the day, almost always in bright sunshine. It's hot, sweaty, grimy and unpleasant. On the other hand, I can run early in the morning, late at night, in a climate-controlled facility, every night if I were so inclined.
d. To my knowledge, I've never gotten into a cardio-strengthening sustained pulse rate while mowing. It's just not the right exercise for that.

If the price of gas went to $50/gallon, I'd stop going to the gym, and run on the streets at home, or on a home treadmill. I still wouldn't consider the gas or reel mower to sufficient for the kind of workout I want to do.



Coincidentally enough one of the Seinfeld re-runs on TBS yesterday afternoon was the one where Kramer feeds the horse Beef-a-Reeno


?!- don't tell us- tell Goodall!- this post is inspiring- we should have green nerd SWAT teams go around and debunk all the repub talking points (as long as they don't hire even smarter red nerds to trounce the greenies)


Missing the point. Many people want to lose weight, and walking and NOT eating these extra calories is great for the environment and their waistlines. And then they'll weigh less and get better mileage in their cars later, too :)


So are they saying we would be less hungry (reducing carbon emissions by not eating beef), if we drove more?


None of this data ever mentions the energy cost associated with building the infrastructure to drive. If the the energy used to build and maintain roads and vehicles was included here, this wouldn't even be close. Instead, they are looking at a very limited data set. Also misleading (at least in the coverage of these studies), is making the assumption that the people who walk would eat more and the people who drive eat less.


I think what clouds this whole issue and what many economists fail to see is that individuals are already going to be looking to burn that 200 calories, either at the gym on a treadmill, jogging, or by walking instead of driving.
So if you do
(a) Drive to work and then use a treadmill. You have to bite all the harms of burning 200 calories, you have to power the treadmill, and you have to power the car. Thats 3 different sources that contribute to your carbon footprint.
(b) Drive to work and jog outside. here you bite the harms of burning 200 calories and to power the car. thats 2 different sources
(c) Walk to work. The only harms that exist here are from burning the 200 calories. Only 1 source.
So it seems environmentally sound to walk to work or wherever else you are going only if you are looking to burn that 200 calories elsewhere, because if you are then the energy to power the car is entirely extra.



I'm with MM.

jb, I'm very glad that your spoiled mentality of not being able to so much as run outside is causing so many externalities to be thrown at me. And that's not even considering your presumed "need" for a turf-grass lawn that is probably worse for the environment than if you paved it in concrete. And have you even considered a mechanical, push mower (no gas)? That'll increase your cardio, I bet, especially if you jog behind it like I do.


I like how people buy labor saving devices like fancy lawn mowers and robot vacuum cleaners so they can hurry up and get their lawn mowed in order to have time to drive to the gym and run on a treadmill.


The only conclusion that one can come to is that the best thing one can do for low GHG emissions is to reduce (not eliminate) your meat consumption.

Now, possibly with the delayed solar cycle, the recent colling of the planet, and the crazy winter we just had we may want to be pumping GHG up to avert the next ice age. Who knows what's really going on, climate science is far too new to make any calls either way.


well, somebody also needs to calculate the foot print of nothing-else-to-do researchers driving to their environmentally controlled office, use the power to turn on their fancy computers, the cost for the grid that provided them the electricity, etc....Now, that will be an excellent research idea.

Maybe the conclusion is everyone should commit suicide? wait...someone tell me the carbon footprint for the gun manufacturer, bullet, energy to transport that, energy to cremate or dig up a hole and embalm...etc...


For every minute of walking, the average person lives 3 minutes longer, so maybe that's another justification for not walking places. Longer living certainly increase carbon footprints right?


jb, I think you're missing the point of the first post. I don't think he was saying that you'd get your workout from mowing the lawn, just that the footprint you're leaving is negated by the fact that you drive to the gym to run on a treadmill.

I'm not endorsing his comments, I just think your response was a bit off point.



Wait a minute... why are we even researching this?

Suppose for a moment that driving in some sort of super-efficient non-human-powered vehicle resulted in a lower carbon footprint than walking/biking/etc. Would anyone seriously consider giving up that exercise? Do people not understand that, as humans, we were built to move under our own power and incur dire health consequences when we don't?


in general, i think the meat-guzzler that is the modern western diet is almost as bad as the gas-guzzler that is personal transportation in terms of carbon production... right up there with rice grown in rice paddys, and home heating and office building cooling. there are lots of sources of greenhouse gasses, and haggling over which one or the other causes a marginally worse impact does nothing of use... wait, it is fun to blog about...

moving on...

scott @ 12: you seem to be implying that we're in equilibrium between carbon produced and carbon absorbed. if that was at all the case, then global warming couldn't possibly be an issue.

if you are only merely suggesting that if we humans stopped adding extra carbon, there might be some sort of opposite backlash, i think the possibility is extremely remote. considering that for 99.7% of the existence of life on earth, we weren't going about addind extra carbon, and that most major adaptations take relatively long amounts of time, i doubt that the world has morphed into a state where a reduction in greenhouse gasses would cause serious backlash. it just doesn't pass the sniff test.


random comment: why is it that some people put down environmentalism as "too expensive for business," yet the expense of expelling undocumented immigrants seems to be of little consequence to them?



Riding a bike cuts energy expenditures by 60 to 80% (increasing travel range by a factor of 3 to 5) over walking.

In high traffic energy expenditure is nonlinear, everyone stuck in the traffic jam burns more gas and wastes more time. Cyclists and pedestrians are less effected.

May is bike month. Instead of a gas tax break, why don't we all use our rebate checks to buy a bike and make 5% of our trips on two wheels instead of four.


Perhaps this research would be more interesting if I went to the store every time I wanted a meal. Instead, I usually frequent the store only once per week and purchase much more food for my family of six than I could carry home with me on foot. I also buy food in bulk and store it in my basement; those trips down the stairs don't use much carbon at all. So for the way I buy and consume food, it's a lot more carbon-efficient for me to drive.


Yet another thing not being considered is that a zero carbon footprint probably has unintended consequences. The environment has adapted to handle things decomposing, burning, being flatulent, etc. With too few greenhouse gases, I'm sure that something bad would happen. I'm curious what the right carbon footprint per person is. I would wager that the planet will adapt to whatever we do. The worst case scenario is that the plantary adaptation causes lots of death and destruction to bring things back into balance. The best case scenario is that no one dies, but we all adapt. I highly doubt that any scenario involves the complete destruction of all life.