A nuclear power plant equals 100 billion bags of potato chips

PepsiCo’s Walkers unit in the UK spent two months to figure out that the carbon footprint of a bag of chips is 75 grams (Business Week). There are about a million grams in a short ton, and at $20 external cost of a ton of CO2 that’s 0.2 cents (see my previous posting about those numbers). Of course, there are no regulations covering how this number is generated, and there is no audit, nor any liability for PepsiCo if they get it wrong. But even at face value, we have a new reference point for CO2 emissions: bags of chips.

So consumers are supposed to include this as a guide to their behavior. What’s wrong with this picture? Well, let’s look at some other alternatives a consumer can look at.

Replacing a single 75W incandescent light bulb with an energy star alternative saves 100 lbs per year (EPA estimate). That’s 600 potato bags per year.

A typical pair of cheap PC speakers (with subwoofer) that are left turned on 24/7 can on passive use pull 40W. That’s what one of mine did that I measured using the highly useful Watts Up? meter. In terms of bags of potato chips, that’s almost 3000 bags. Turning off those speakers when you’re not playing games will save you thousands of potato chip bags.

Replacing an old gas or oil furnace or boiler with a new one saves about 3000 lbs per year of emissions (again, EPA estimate). That’s about 20,000 bags of potato chips per year. Per household.

The EPA estimates the average US household emits 41,500 pounds of CO2 per year, in total. That’s the equivalent of a quarter million bags of potato chips. So consumers are supposed to approach the CO2-reduction in their lifestyle in increments of 1/250,000?

Building a single additional nuclear power plant unit (upping our national production by less than 1%) instead of coal-based power is equivalent to about 100 billion bags of potato chips each year. Those are more interesting increments in my mind.

Carbon labeling products like potato chips is a nutty approach to global warming. It’s about being eco-chic, about feeling good, not about actually doing something about the problem. Plus it’s misleading, since a price difference of 1/5 cents is more significant than whether or not you buy that bag. The only practical solution is of course a carbon tax, which will allow the market to figure out how to minimize the aggregate effects.

Still, you do save CO2 by eating the chips and then walking it off, instead of driving. By my estimates, your car emits the equivalent of six (6) bags of potato chips per mile. If you use the chips directly to fuel your own biological engine, a single bag will get you about 1 1/2 miles, so that’s about ten times as efficient.

Now that would be a smart consumer decision.


  1. Peter, thanks for your comment on my carbon labeling post over at Flamming Grasshopper (crossposted at Fguide.org). I’m not sure what you were referring to about an analogy with dietary labeling, but it was interesting to see your point about the absolute scale of something like a bag of chips. Yes, in the grand scheme of things, carbon labeling a bag of chips hardly seems worth the effort. However, in the context of an attempt to introduce carbon labeling as a general scheme, it seems to make sense to be more inclusive rather than less, though even assuming that’s true it still is sensible to rank the importance of items in terms of which you calculate and label sooner rather than later (since not all can be labeled immediately). Also, even something as absurdly micro-emitting as a bag of potato chips can benefit from a labeling scheme, assuming the labels allow for easy comprehension of relative emissions. Any one bag of chips is associated with minuscule emissions. But one heck of a lot of bags of chips get produced and sold each year. For all we know, depending on type of oil the chips are fried in, the source of the potatoes, and the transport involved, there might be significant disparities between one bag of chips and another. Linking back to my preference for as near to universal labeling as possible, even something as minor as the chips can be part of a cultural change in which people start noticing relative carbon impacts and making informed choices as a result. The bags of chips themselves don’t add up to all that much, but their contribution to changed behavior could reach beyond that.

    [PSM] Jonathan, thank you for dropping by and commenting. I see your point of being more inclusive rather than less. But I think therein lies a great danger; what I find lacking in the public reaction to global warming is a good sense of proportion. We need to have significant policy discussions on the emissions side (e.g. should we or should we not accelerate growth of nuclear power, and if so, how? should we accelerate improved building codes?) and the “damage” side (e.g. what infrastructure projects in Bangladesh should we be starting? how will we organize redistribution of carbon taxes globally?). Labeling the carbon footprint of a bag of chips is sharply out of proportion, therefore a distraction, and therefore an injury (however slight) to moving public policies forward.


  2. I show on the Miastrada website (click my name) a way to drastically reduce CO2 emissions yet still drive around fast in personal cars. The main sacrifice is the usually empty right front seat. And I am not talking about potato chips. This really makes a big difference.

    But we do need for people to realize there is a meaningful choice and that there is a reason to seriously rethink the way we ride in cars and how they should look.


  3. Ok if all thats true, but the question is do you know how much cups/ounces of oil is in a bag of chips in general? Also, what types of oil is used in the diffrent amount of chips? People look at it the way when its like300 cups of oil it would amuse them and then thy would like to save. But to them a bag of chips looks small and has no meaning to them. Thats why a few people are taking the situation seriously.

    [PSM] Well, there’s about half a cup of oil (gasoline) worth of CO2 in a bag of chips, apparently. Which is a striking amount, but the point is that it’s a useless scale in which to be thinking about the problem. World CO2 emission, with these metrics, is 200,000,000,000,000 cups of gasoline (equivalent). My point is that our debate shouldn’t be about eating fewer bags of potato chips, but about building fewer coal plants and more nuclear plants. It’s the production of energy that matters, more than the consumption.


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