Math Lessons for Locavores

[groovedaddy]

IT’S 42 steps from my back door to the garden that keeps my family supplied nine months of the year with a modest cornucopia of lettuce, beets, spinach, beans, tomatoes, basil, corn, squash, brussels sprouts, the occasional celeriac and, once when I was feeling particularly energetic, a couple of small but undeniable artichokes. You’ll get no argument from me about the pleasures and advantages to the palate and the spirit of eating what’s local, fresh and in season.

But the local food movement now threatens to devolve into another one of those self-indulgent — and self-defeating — do-gooder dogmas. Arbitrary rules, without any real scientific basis, are repeated as gospel by “locavores,” celebrity chefs and mainstream environmental organizations. Words like “sustainability” and “food-miles” are thrown around without any clear understanding of the larger picture of energy and land use.

The result has been all kinds of absurdities. For instance, it is sinful in New York City to buy a tomato grown in a California field because of the energy spent to truck it across the country; it is virtuous to buy one grown in a lavishly heated greenhouse in, say, the Hudson Valley.

The statistics brandished by local-food advocates to support such doctrinaire assertions are always selective, usually misleading and often bogus. This is particularly the case with respect to the energy costs of transporting food. One popular and oft-repeated statistic is that it takes 36 (sometimes it’s 97) calories of fossil fuel energy to bring one calorie of iceberg lettuce from California to the East Coast. That’s an apples and oranges (or maybe apples and rocks) comparison to begin with, because you can’t eat petroleum or burn iceberg lettuce.

http://www.nytimes.com/2010/08/20/opinion/20budiansky.html?th&emc=th

[RandomThoughts]

1. Note, the groups that believe in local food production.

that are against the WTO and things like that, are not anarchist, although some take that name, they are not trying to remove rules, they are trying to make issues more equal.

[Dead_Parrot]

2. Careful...

...I dared to question the sanctity of food miles a while back and went down like the Hindenberg. People like simple rules, not hard stuff like math...

[AlecBGreen]

3. +1

"People like simple rules, not hard stuff like math..."

as a teacher I cant tell you how often my freshmen whine, "Just TELL US what to doooooo!" Logical, coherent thinking for oneself is apparently kryptonite to most American teenagers in my neck of the woods. Sadly, it appears this doesn't wear off with age.

[txlibdem]

4. You can't eat petroleum

I'm not disagreeing with you entirely, but food miles is a more complex topic than you make it out to be. And comparing greenhouse crops to ones shipped from the opposite side of the country is problematic in a number of ways.

The greenhouse you decry may not get it's heat from fossil fuels. Would your opinion change if the greenhouse used waste heat from a nearby building or factory? Or if the greenhouse was 100% electric and was powered by under-water turbines getting their power from the nearby Hudson River? Would it change your opinion if you knew that the greenhouse-grown veggies use only 5% of the water that a field-grown crop would use? How about if it uses electricity for heating and lighting the greenhouse - and that electricity came from the wind. Or solar. Or nuclear power plants?

In other words, a greenhouse tomato is always better than field grown in terms of water usage (even those grown right next door to each other). In addition, the greenhouse can improve its carbon footprint. A trucked-in tomato from clear across the nation cannot.

[Dead_Parrot]

5. On the other hand...

...the greenhouse has to bring in the fertilizer: a field can be left fallow for a time to recover, but I've never heard of a commercial greenhouse doing that - not surprising, as it's a closed system (of course, fields aren't often left fallow either, but it's always an option). They could replace the soil in bulk, which I've not come across, or top-up the soil with fertilizers and nutrients which carry their own cost.

There's also the question of microflora and microfauna. The activities of these are responsible for a large chunk of the natural carbon cycle - about 60Gt/Yr, an order of magnitude over fossil fuel releases - and in an artificial environment the natural balance goes to pot: If your greenhouse's soil is constantly seeping methane because you've got the wrong sort of nematodes, you can easily match the damage done by a truck run every three months.

Swinging the other way for a second, there are two ideas you missed: Composting greenhouses, where the crops are grown on deep troughs of waste, are self heating and to an extent self fertilizing: You need to keep an eye on the levels, but it kills the heat, fertilizer and local waste problems with one stone. Or, "animal heated" greenhouses where you produce tomatoes and eggs (or whatever). You get a source of heat, a supply of fertilizer, and a commercial sideline.

Of course, almost nobody does these, either.

The ideal solution would be to stop demanding fresh tomatoes in the middle of winter - like that's ever going to happen.

[Terry in Austin]

6. Food fight: setting the "curmudgeon" straight

This piece was so amazingly wrong in so many ways, I didn't quite know where to start. Fortunately, there are others who also noticed, and went ahead and plowed right in.

Check out the roundtable at Grist. It isn't about misplaced math lessons...

It's about peak oil:

{U}nlike Mr. Budiansky, ...I have noticed that oil supplies are peaking. In 20 years, I have no reason to assume that this massive fossil-fuel-based system will be able to find the oil it needs to bring foods to local stores, let alone whether I will be able to afford price of that energy. I want to bring those sources of uncertainty a little closer to home, where I can see them.

It's about sound argument:

{Budiansky} totally misses the point. ...To begin rebutting this pack of B.S., I must correct his notion of locavory. Despite attempts by national retailers to reduce "local food" to a mere question of miles, true locavores are after more than just miles. At its heart, the movement is about relationships.

It's about better public policy:

What we grow and where we grow it is the predictable result of massive public subsidies to the largest industrial producers. {T}he question that we locavores are asking is what kind of support and subsidies should we have, directed at which outcomes, and in whose interest? Do we want a food system that subsidizes chemical farming and feedlot meat production... Or one that fosters sustainable practices, fairly paid farmers and food workers, clean water and healthy soils, all while bringing us affordable good-tasting food?

[Javaman]

7. One also has to eat seaonally...

My wife and I try as best as we can to eat only local produce and what this means is eating only what is in season.

When we visit our local farmers market, we ask them how the vegetables were grown. Just buying them doesn't necessarily mean they are green, just that they are organic.

While sometimes it's tough to keep to the seasonal commitment, once you get used to it, it becomes just part of life like anything else.

This type of eating is how all humans once fed. We will eventually go back to this way again, but it will take a while.

Bottom line: educate yourself about the food you eat, how it is grown and how far it has traveled.