You Eat What You Are, Part 2 (Ep. 78)

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(Photo: Carl Wycoff)

Our previous podcast, “You Eat What You Are, Pt. 1,”explored how American food got so bad, how it’s begun to get much better, and who has the answers for further improvement.

Now it’s time for “You Eat What You Are, Part 2.” (You can download/subscribe at iTunes, get the RSS feed, listen via the media player above, or read the transcript here.)

In this installment, we look at the challenge of feeding 7 billion people while protecting the environment, especially from all the pollution associated with the long-distance transportation of all that food. In that regard, it would seem that going local is a no-brainer — until you start to look at the numbers.

We begin with David Cleveland, an environmental studies professor at U.C.-Santa Barbara. Santa Barbara County grows $1.2 billion worth of produce a year, putting it in the top 1 percent of U.S. counties. Cleveland started out simply trying to learn how much of the produce consumed locally was also produced locally:

CLEVELAND: This is what really shocked us: we found that when you added up all these different ways in which locally grown produce got to people in Santa Barbara County, that less than five percent of the fruits and vegetables consumed in Santa Barbara County were actually grown in Santa Barbara County, and the other ninety-five percent were imported.

Next, Cleveland wanted to know what kind of environmental and nutritional effects would result if Santa Barbara were to go totally locavore. (The resulting paper, “Effect of Localizing Fruit and Vegetable Consumption on Greenhouse Gas Emissions and Nutrition, Santa Barbara County,” can be found here.)

CLEVELAND: We wanted to look at what effect 100 percent localization of the Santa Barbara County system — which is a physically and biologically a very feasible thing to do — what effect would that have on greenhouse gas emissions? And we found that it wouldn’t make a lot of difference. Our savings in greenhouse gas emissions, per household, as a proportion of the total food system greenhouse gas emissions, was less than one percent.

Cleveland’s research built on earlier work by Christopher L. Weber and H. Scott Matthews. (You’ll hear from Weber in this episode as well; he used to teach at Carnegie Mellon and is now a researcher as the Science and Technology Policy Institute.) Their paper (PDF here) is called “Food-Miles and the Relative Climate Impacts of Food Choices in the United States.” We’ve written about it before; it argues that the vast majority of the energy associated with food production is in the production phase rather than the transportation phase, which means that relying on locally produced food as a means to limit pollution isn’t necessarily a winning battle.

You’ll also hear from economist Ed Glaeser (whom you might remember from our “Why Cities Rock” podcast). He too took notice of the Weber-Matthews argument but put his own spin on it: Glaeser is an urbanist who feels that by overvaluing ideas like local-food production (a garden in every yard, e.g.), we are potentially undervaluing the greater gains to be had by living more densely. Glaeser also talks about why we get so emotional about food in the first place:

GLAESER: The idea of there being something wrong with our food cuts to the very heart of our stomachs; of our souls, almost. So it’s not so surprising that people have these deep emotional reactions to food. And we certainly are right to worry a lot about whether or not our food is fresh, and good, and tasty, but I just keep coming back to feeling a certain amount of satisfaction that I’m eating grapes that are keeping up the standard of living in Chile.

So what’s an environmentalist to do? For starters, as Weber-Matthews suggest, stop eating so many cow products. As we put it in SuperFreakonomics:

It is generally believed that cars and trucks and airplanes contribute an ungodly share of greenhouse gases. This has recently led many right-minded people to buy a Prius or other hybrid car. But every time a Prius owner drives to the grocery store, she may be canceling out its emission-reducing benefit, at least if she shops in the meat section.

How so? Because cows — as well as sheep and other cud- chewing animals called ruminants — are wicked polluters. Their exhalation and flatulence and belching and manure emit methane, which by one common measure is about twenty-five times more potent as a greenhouse gas than the carbon dioxide released by cars (and, by the way, humans). The world’s ruminants are responsible for about 50 percent more greenhouse gas than the entire transportation sector. …

The best way to help, Weber and Matthews suggest, is to subtly change your diet. “Shifting less than one day per week’s worth of calories from red meat and dairy products to chicken, fish, eggs, or a vegetable-based diet achieves more greenhouse-gas reduction than buying all locally sourced food,” they write.

You could also switch from eating beef to eating kangaroo — because kangaroo farts, as fate would have it, don’t contain methane. But just imagine the marketing campaign that would be needed to get Americans to take up ’roo-burgers. And think how hard the cattle ranchers would lobby Washington to ban kangaroo meat. Fortunately, a team of Australian scientists is attacking this problem from the opposite direction, trying to replicate the digestive bacteria in kangaroos’ stomachs so it can be transplanted to cows.


I think this presented a much more balanced approach than Freaknomics has taken to the local food market in the past, at least with some of the posts on the blog.

The way I look at it is, dollars = votes. By buying local food you don't necessarily have to image a "local" utopia but it is a way of letting the food industry know you don't approve. There are obvious benefits to a more global system, especially in terms of stability but things have obviously gotten out of control.

Enter your name...

"Letting the food industry know you don’t approve" of what?

I live near the biggest strawberry fields in the USA. Standard, conventional, commercial strawberries are "local" for me. I could actually ride a bike out to buy fruit from several strawberry growers. So if I "buy local", what exactly am I disapproving? And why is it that you think exactly the same strawberries carry a different message two big cities away (a place whose climate makes growing strawberries wildly inefficient)?


I probably should have been more specific. The Farmer's market I goto has quite a bit of meat. I have tried to buy all my meat and eggs there instead of the grocery store.

I know you can find meat without anitbotics/hormones and/or grass fed outside of the farmers market, but living in Ohio they are basically from the same source anyways. Its really not the travelling that I am concerned about it is the practices that have been compromised to maximize profit/output. In terms of produce we do buy a lot at the Farmers market but that is mostly due to the seasonal issue. When tomatoes are in season the prices are often times better than the super market.


I'd be interested to know how the cost of venturing to and from the local farmer's market factors into the economic impact of buying locally. I would presume that most people drive to and from the market (I know I do), and maybe some people drive further (or much further) to get to said market than they would to get to the grocery store.

Here, our farmer's markets are located downtown, so in order to get to them you have to drive 15-20 minutes to the place, drive around looking for a parking space, and then drive home. Whereas with the grocery store, you drive 5 minutes, park, and leave.

Enter your name...

It happens that I can and do walk to both the nearest farmers' market and the nearest grocery store. But I think you're on to something: my area has something like four big grocery stores for every farmers' market. On average, people will drive much further to the farmers' market.

But our big grocery stores also make a point of buying local produce, so a trip to the farmers' market is not actually necessary to acquire local produce. (And I don't mean the "somewhere in the state, or the next one" kind of local, but the "Here's a bin of apples from this specifically named apple producer, whose orchard all the schoolkids in the county visit during first grade" kind of local.)

Guy Judge

Just a small point - according to my colleague Andy Thorpe 96% of the methane emitted by cows comes from burps not farts! Do kangaroos fart?
Thorpe, Andy (2009) Enteric fermentation and ruminant eructation: the role (and control?) of methane in the climate change debate. Climatic Change, 93 (3/4). pp. 407-431. ISSN 0165-0009

Eric M. Jones

"...David Cleveland, an environmental studies professor at U.C.-Santa Barbara...."

Ahem, so now we know why this very strange county is used as a standard, but cummon....Santa Barbara (known as the American Riviera) is so wildly non-average that I'd be really careful about drawing conclusions based on it....

There average knock-down fixer-upper house in the city of SB is well over $1,000,000.00

Enter your name...

Actually, when I looked up the current listings, it appears that $1M will get you some rather nice 4 bed/4 bath homes on large lots these days. Perhaps the last time you looked was in 2007, when the median single-family home price (not fixer-uppers) was running just over $1M, or you were looking in a particular neighborhood?


I found this topic very interesting, but also thought that a huge opportunity was missed in actually talking about the cost of meat production, especially since the topic was introduced in this episode. At the end of the episode (as on these notes), you did touch on Meatless Mondays, and the environment issues of cows, but to then turn the discussion to transferring cow production to kangaroos is just ridiculous! I get that maybe it's to be snarky or a joke or something, but there is so much information demonstrating that raising animals for food is enormously energy-intensive, waste-producing, and resource-sucking. To say that we should stop raising one animal for food and sub another one is, is not only cruel in a day when meat unnecessary for nutrition and is costing us our health and resources, but is also just preparing to replace one type of problem with another! I'd love to see this topic revisited, with the same opening line "who has the answers for improvement," and take a hard look at the meat industry and the obvious answers to it.


Christopher Browne

I'm not so sure that the suggested action will actually have the desired effect.

Namely, the fact that some people decide to stop eating beef may not lead to the desired change in levels of production of beef.

If only *some* people stop eating beef, that may lead to the price of beef *slightly* lowering, making it more economical for the rest of us to "pull up the slack" and eat the resultant cheaper beef more often, and, importantly, still allowing the market for beef products to, in economic terms, continue to "clear."

I suspect that the *real* set of actions to reduce beef production would involve heading down a much more disturbing trail that would smell more than a little like terrorism.

- Gotta make sure that people are a little afraid to eat beef. BSE / Mad Cow Disease was pretty wonderful for that a few years back.

- Gotta make sure that farmers are a bit afraid to produce beef, considering it a risky endeavour. BSE had this same effect. Relatives in Western Canada found BSE to be quite an injury to their farming.

Dilettantes may say "I'll stop eating beef." Those seriously trying to effect change probably need to find and try to spread the next "BSE." And they'd need to be sufficiently cold-blooded to realize that they'll be inducing the deaths of millions of cattle. And realize that farmers have sufficient troubles with wild animals that they tend to be reasonably well-armed...



"And think how hard the cattle ranchers would lobby Washington to ban kangaroo meat. Fortunately, a team of Australian scientists is attacking this problem from the opposite direction, trying to replicate the digestive bacteria in kangaroos’ stomachs so it can be transplanted to cows"

Does anyone else see it as odd that, as a society, we would rather genetically bastardize cows than just switch to eating a different kind of meat?


Or come to terms with eating less or no meat altogether.

jay cobal

Joel Salatin of PolyFace Farms has a very convincing response to the notion that it is cows that are responsible for methane production and could be reduced by cutting back on beef:

Robin Marlowe

Left out of the calculations for going local and organic: fertilizers and pesticides. Any chance you can run those numbers for us, your loyal audience?

Thank you!


Farming techniques involving synthetic fertilizer, draining ancient aquifers, waste runoff, etc I'll agree are a major problem, but I'm not convinced about the methane argument with respect to cows. A bit of googling reveals that the breakdown of plant matter in the world's wetlands produce far more methane than red-meat farmed animals.

Equally important to the increase in methane emissions is that methane is quickly reabsorbed back out of the atmosphere. Methane takes a dozen years to leave the atmosphere--in contrast to the hundreds of years for carbon dioxide and oxides of nitrogen. For this reason, the tiny extra methane emission over and above that naturally occurring in wetlands (or anywhere else where plant matter is decomposing) will quickly stabilize as the reabsorption rates increase with increased concentrations. This is similar to another chemical that is far more potent at trapping heat and is released into the atmosphere in prodigious amounts; with this other chemical, the removal from the atmosphere is so common we have a special name for it: "rain."



It would be informative to compare the amount of methane produced by burping cows to that released as a byproduct of oil & natural gas extraction, and from coal mining.

We might also compare the cow population (about 100 million) to the size of the buffalo herds - estimated at 30-60 million animals. The buffalo is similar enough to the cow that they can be crossbred to produce fertile offspring - "beefalo" or "cattalo", and is, on average, a larger animal, so there should not have been that much overall change in bovine methane emissions. Many other large grazing animals - sheep, deer, moose, etc - are also ruminants, and so their digestive systems would produce methane.

The Aggie

Most of this - and quite a bit more that is not touched upon - is not 'news' to agricultural economists. A much more meaningful and detailed discussion on this topic would take place at UC-Davis, Riverside or even Berkeley, not Santa Barbara. When, oh when, will 'general' economists stop 'discovering' food as a topic?


On the matter of cows and their burps, I do think you folks ought to do a little background research on the carbon cycle, instead of apparently relying on the Heartland Institute for information. It's the addition of a large amount of CO2 from fossil fuels that is responsible for global warming, not minor changes in the number of cows.

Cows - like all animals, ultimately - eat plants, breaking down complex carbon compounds to CO2, and sometimes methane, which quickly degrades to CO2 and H2O. Plants then use the CO2 plus sunlight to produce more complex, energy-rich carbon compounds. This is a cycle: there is no net increase in atmospheric CO2 over time. (Though actually you can see a small yearly variation as northern hemisphere land plants increase photosynthesis in the summer.) Any change, such as increasing the number of beef cattle in the US, or sharply decreasing the number of grazing buffalo in the mid-19th century, don't really affect this cycle.



Kangaroos fart methane after all


An interesting link from that page, hypothesizing that increased CO2 is responsible for the obesity epidemic: