Adventures in Ethics and Science

At the New York Times Room for Debate Blog, a bunch of commentators were asked to weigh in with easy-to-make changes Americans might adopt to reduce their environmental impact. One of those commentators, Juliet Schor, recommends eating less meat:

Rosamond Naylor, a researcher at Stanford, estimates that U.S. meat production is especially grain intensive, requiring 10 times the grain required to produce an equivalent amount of calories than grain, Livestock production, which now covers 30 percent of the world’s non-ice surface area, is also highly damaging to soil and water resources.

Compared to producing vegetables or rice, beef uses 16 times as much energy and produces 25 times the CO₂. A study on U.S. consumption from the University of Chicago estimates that if the average American were to reduce meat consumption by just 20 percent, that would be the equivalent of switching from driving a Camry to a Prius.

Americans currently rank second in world in meat consumption, weighing in at 271 pounds a year, up from 196 pounds 40 years ago. And that doesn’t include dairy. We get an estimated 75 grams of protein a day from animals, and 110 grams total; the government recommends only 50 grams a day.

The idea of eating lower on the food chain to save the planet isn’t a new one. However, this isn’t a suggestion that helps the Free-Ride household reduce its environmental impact, since we are already meatless.

What’s more, figuring out how to tweak our dietary choices to further reduce our impact is made difficult by the lack of transparency about the real environmental costs of our options. The labels in the supermarket don’t list how much water, land, or petroleum-based fertilizer went into producing your pound of potatoes or peas. Nor do they reflect the amount of energy used to process your tofu, nor the natural resources to can you chickpeas, nor the fuel to ship your bananas.

All of which makes it very hard to know how to make better choices about the foods we eat.

For example, so far this year we’ve been eating significantly more legumes each week. Nutritionally, they’re a slam-dunk, high in fiber and protein. And, since legumes tend to enrich the soil they’re grown in, I’m hopeful that we’re expending less fertilizer than we would be otherwise. So far, so good. But now, in our quest to be environmentally responsible, should we be buying beans in cans or bags of dried beans?

The dried beans need to be soaked in water, then boiled in water (and it’s generally recommended that you don’t boil them in the water you soaked them in). So, here you’re consuming water (which we’re very short on in California) plus whatever source of power you use for cooking — just to get your legumes ready for your recipe.

Canned beans, on the other hand, don’t need to be soaked or boiled … at least not at home. I’m unclear on what state the beans are in when they enter the processing plant — maybe they’re freshly picked, but maybe they’re dried beans that need to be soaked and boiled at the factory before being canned. (The latter option strikes me as a silly one, but as a consumer, I can’t rule it out.) The beans are packed in steel cans — it takes both metal and energy to make those cans and to put the beans in them. And while steel cans are recyclable, recycling requires energy inputs, too.

Indeed, there’s packaging for the dried beans, too — plastic bags — which requires petroleum and energy to make. And unless the legumes are sun-dried, there’s likely an energy input required to dry the beans.

So, dry or canned? Which choice is more responsible? How on earth is a consumer supposed to evaluate this choice?

The cooking method introduces another decision point where I don’t have as much information as I’d like. Lately, I’ve been rocking the slow-cooker. It tends to use less water than cooking stuff in a pot on the electric range, but over a much longer cooking time. Am I saving water only to use more electricity? Is there a good way to evaluate this?

If any of y’all know a good source for this kind of information, can you point me toward it? I have a feeling that there are other people who would like to take account of the environmental costs associated with their food choices, if only they knew what those costs really were.

Comments

#1 anon
February 26, 2009

I wonder if you could become essentially autotrophic.

For starters, Suppose one covered ones roof with a sort of solar panel that grows spirulina.

Basically a sealed water filled panel. Then a pump to circulate water, taking co2 out of the air in your house, and the nitrates and minerals from , uh, bodily wastes. Maybe after composting in a composting toilet.
#2 Janne
February 27, 2009

Not that long ago there was a well-publicized study showing that eating just a little meat – but not going altogether vegetarian – is optimal from an environmental standpoint. Basically you can support some level of meat and dairy production with the scraps from farming and our own food wastes, and there’s some amount of land that is very good for pasture but not for farming. And the resulting product – meat and dairy – is high quality (energy and nutritionally) and uses relatively less resources for processing and transport. So going entirely meatless would increase the overall environmental impact over having a limited amount. of course, that doesn’t mean everybody should eat meat; it’s the average that counts.

For the bean question: my thought is, dried are substantially better. The water is only wasted if you throw it away. If you use it to water your plants, for instance, the effective water use is zero since you avoid using tap water for that. When we wash the rice before boiling, my wife always uses the wash water for our houseplants; the water has a lot of nutrients that the plants can make use of, making it better than unused tapwater for them.
#3 Kim
February 27, 2009

There’s a device you can use to find out how much electricity various devices use. I think it’s called “Kill-a-watt.” I haven’t used it, but I know people who have. It might be useful for testing whether the slow cooker uses more electricity than the stove. (Could be a cool experiment for the sprogs, too.)
#4 Larry Ayers
February 27, 2009

I’m reasonably sure that canned beans enter the cannery dried; pintos, great northerns, etc.

A good source of info on complementary protein from vegetable sources is “Diet For a Small Planet”, by Francis Moore Lappé.
#5 D. C. Sessions
February 27, 2009

A good source of info on complementary protein from vegetable sources is “Diet For a Small Planet”, by Francis Moore Lappé.

And I’m going to say some seriously rude things to whoever (the ex?) made off with my copy of “Recipes for a Small Planet.” Great cookbook, that.

Canned beans come into the factory dried, because that’s how the mature seeds are in the field. Soak, boil, etc. all in the plant. It’s a bit more water-efficient than at home, but not that much. Yes, the water for soaking (with a pinch of baking soda to reduce flatulence) can be used in the garden — it’s a very low-grade form of grey-water recycling. Actually, a lot of cites (Phoenix, for one) process sewage into tap water anyway.

Pressure cookers are more efficient both for energy and water use.

If you have the land (I do) you can landscape with edible plants. Route your roof gutters and arrange runoff correctly and you can get by without much added water; grey-water of course helps. This year it’s scarlet runner beans (which are water misers and grow like lightning, plus they fix nitrogen), okra (another low-water explosive grower), basil, tomatillos, and a few curcurbits. Maybe some others; there’s a new arbor on the west wall that needs some fast growth to keep the wall shaded.
#6 gmh
February 27, 2009

The figure that livestock production covers 30% of the terrestrial land surface (excluding ice) beggars belief.
#7 Sarah
February 27, 2009

Seems to me that dried beans are far superior, not only because of the reduced packaging waste, but because they’re so much lighter to transport. I’m sure there are efficiencies in bulk cooking but I’d be shocked if they made up for the additional energy required in canning. Water use at the household cooking scale is pretty negligible, and soaking/ cooking water doesn’t have to go down the drain.
#8 speedwell
February 27, 2009

If, like me, you are a diabetic managing to keep her blood sugar under control with a low-carb diet (works well for me, YMMV), then you must buy canned… why?

Because the only cooked dried haricot-type bean that isn’t sky-high in carbs (and too high in glycemic impact, despite the fiber) is black soybeans. If you try to cook those things yourself, you’d better have some time on your hands… literally days in a slow cooker, all day in a pot, and at least a couple-three hours in a pressure cooker.
#9 chezjake
February 27, 2009

My inclination is to think that dried beans are more energy friendly than canned, but I don’t have data to back that up. It’s certainly possible to dry beans without an external heat or air circulation energy source, but I’d guess commercial growers probably do something to speed up the process.

Here’s another thought: Has anyone done any research/development toward producing an economical solar powered slow cooker? It seems something like that could become quite successful commercially and could prove very useful in developing countries as well.
#10 Larry Ayers
February 27, 2009

I saw just such a solar slow cooker a few years ago at Dancing Rabbit, a neo-hippie ecological community in Scotland County, Missouri. Google it; they might have a plan available.
#11 Katrin
February 28, 2009

I’d say dried beans are better – lighter weight for transport, and as far as I know, you can use the soaking water for cooking with most sorts. I have even read recommendations that you should not replace it, because it contains a lot of minerals after soaking.
For energy-efficient legume cooking, a good long soak helps a lot – and then you could heat up the pot to a good boil and then stuff it into a haybox or into a similar insulated environment. What worked with the electricity shortage in post-war Germany should work for energy-saving purposes today!
#12 D. C. Sessions
February 28, 2009

For energy-efficient legume cooking, a good long soak helps a lot – and then you could heat up the pot to a good boil and then stuff it into a haybox or into a similar insulated environment. What worked with the electricity shortage in post-war Germany should work for energy-saving purposes today!

Mmmmmmm! Cholent.

The slow-cooked bean dish goes back a lot farther than WWII.
#13 Courtney
March 1, 2009

Never, ever eat food from cans if you can help it. Almost all canned food is lined with plastic that contains BPA.

http://www.ewg.org/node/20944
“Our testing of canned foods found that BPA leaches from the liner into the food itself. Sensitive groups such as kids and pregnant women should limit canned food consumption. Beverages appear to contain less BPA residues, while canned pasta and soups contain the highest levels. Rinsing canned fruit or vegetables with water prior to heating and serving could lessen BPA ingestion.”

http://www.govlink.org/hazwaste/schoolyouth/BPA.html
Reduce your use of canned foods by using fresh or frozen foods or foods packaged in other containers like glass or cardboard brick cartons. Save canned foods for convenience or emergencies. Almost all food cans are lined with bisphenol A epoxy resin (sealant) and industry studies confirm that BPA is in canned foods and beverages.
#14 Anna
March 2, 2009

I think that you are looking for information on something called life-cycle analysis or life-cycle assessment. Of course, this isn’t easy information to find, but having the right search terms is a step in the right direction. For example, searching on “life-cycle assessment milk” turns up a journal article titled “Life cycle assessment of milk production — a comparison of conventional and organic farming.” Sound like what you are looking for?