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Can organics feed the world? May 11, 2010

Posted by Angelique in Global warming.
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Robert Paarlberg pointedly decries the Luddite sympathies of elite Western foodies in a recent piece in Foreign Policy. In “Attention Whole Foods Shoppers,” Paarlberg argues that today’s trendy push to make food sustainable, which he defines as “organic, local, and slow,” hampers our ability to solve a more important food problem: world hunger. Defenders of sustainability, swayed by romantic visions of pre-industrial agriculture, want to take us back to the days before artificial fertilizer and genetically-engineered seeds. If successful, they will prevent the developing world from taking advantage of the huge productivity gains that those tools bestowed on the West, thereby ensuring a future as dogged by hunger as its past.

Paarlberg makes several good points, including that farmers in the developing world need access to improved infrastructure (like better roads to bring products to market) and that they would benefit from food-safety improvements such as reliable refrigeration and packaging. Of course, none of these points would be denied by any advocate of sustainable food, so Paarlberg is attacking a bit of a strawman here. I’d like to focus on one of his more controversial views, which centers on the “organic” part of sustainability. Paarlberg states that organic farming is not friendlier to the environment than conventional farming; that, in fact, it’s worse for the environment because it requires the use of more land to grow the same amount of food. If we force organic practices down the throats of developing nations, then, we aren’t relieving their hunger, and we’re actually speeding up the degradation of their natural resources.

Paarlberg cites two reasons for rejecting organic farming. The first is that without the use of synthetic nitrogen fertilizer, which is not allowed under organic standards, developing countries would need a lot more animal manure, which means they’d have to do a lot more land- and resource-intensive animal grazing. Oddly, to support this argument Paarlberg uses statistics from the US:

Less than 1 percent of American cropland is under certified organic production. If the other 99 percent were to switch to organic and had to fertilize crops without any synthetic nitrogen fertilizer, that would require a lot more composted animal manure. To supply enough organic fertilizer, the U.S. cattle population would have to increase roughly fivefold. And because those animals would have to be raised organically on forage crops, much of the land in the lower 48 states would need to be converted to pasture.

This is neither true of the US nor applicable to the developing world. Not true of the US because cattle are not the only source of manure. Currently, excess manure produced by conventional livestock production (especially swine production) results in both miles of manure lagoons and toxic overapplication of manure in areas adjacent to livestock facilities. Redistributing this manure to crops that are currently artificially fertilized would greatly reduce the need for nitrogen fertilizer, but fertilizer is so cheap relative to the cost of transporting manure that doing so is not financially sound. (Pricing the environmental externalities of artificial fertilizer into its cost would address this problem.) Nor is Paarlberg’s point applicable to the developing world. Meat consumption in the developing world is forecast to rise dramatically through 2050 simply due to increased demand as populations become richer, not because of the need for natural fertilizer.* Nonetheless, with more abundant meat comes, inevitably, more abundant shit. One might argue that meat consumption won’t rise without a prior rise in conventional, non-organic, crop production to feed the engine of intensive animal agriculture, but there is an alternative: the development of farms which raise both plants and animals in a self-sustaining balance (more on that below).

Paarlberg’s second argument against organic methods is an oft-repeated one: that organic crop yields are lower than conventional yields, so farming organically requires more land to produce the same amount of food. In his words, “Organic field crops also have lower yields per hectare. If Europe tried to feed itself organically, it would need an additional 28 million hectares of cropland, equal to all of the remaining forest cover in France, Germany, Britain, and Denmark combined.” Implication: organic techniques in the developing world would require massive deforestation there.

Even proponents of organic, such as the folks at the Organic Center, agree that organic crop yields are generally lower than conventional yields. However, it’s important to realize that most organic agriculture still makes use of low-performing monocultures. All the organic lettuce we Whole Foods shoppers get from Earthbound Farm comes from land that is dedicated purely to lettuce production, and producing monocultures this way results in soil that is lower-yielding. Superior yields have been produced by farmers who reject monoculture crops in favor of so-called “stacked” production methods that rotate plant and animal species frequently, but since these efforts are so new and small in scale the evidence remains purely anecdotal. In sum, we shouldn’t write off organics because they are often grown in monocultures with comparatively low yields; we should continue to explore higher-yielding ways of producing organically.

In any case, even though organic yields in the West are typically lower than conventional yields there, they are still far higher than conventional yields in the developing world. Michael Pollan, that foodie guru, cites a University of Michigan study in his New York Times essay Farmer in Chief demonstrating that adoption of modern organic practices in the developing world could increase food production by as much as 50%. It would seem that feeding the world and sustainability are not mutually exclusive goals.

Having said all this, I’m not insisting that organics are the way to go. The moderate in me says that there are almost certainly cases in which a judicious use of synthetic fertilizers or pesticides is part of an optimal food production system. But we do need to get a lot closer to the organic ideal. Paarlsberg misses his mark in dismissing that project as no more than misguided foodie elitism.

*UN Food and Agriculture Organization, Livestock’s Long Shadow, p.10.

Meat: the new diapers March 19, 2010

Posted by Angelique in Global warming.
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I’m sure you recently-minted parents out there know about the diaper controversy. Disposable diapers create mountains (literally) of waste. So, maybe twenty years ago, environmentalists started to attack them as yet another example of Americans’ willingness to trade sustainability for convenience. In response, some well-meaning parents decided to go back to smelly, messy cloth diapers. But then people realized that the environmental impact of washing all those cloth diapers was no joke, either. It turned out the story wasn’t as simple as it first seemed, and it wasn’t obvious what a sustainability-minded parent should do.

The current outcry about the unsustainability of meat-eating looks headed toward a similarly unsatisfying end. Proselytizing vegetarians (among them Paul McCartney, Jonathan Safran Foer, and Peter Singer) are pushing a very simple story: if you want to stop global warming, you should stop eating meat. Credible support for this argument comes from the UN Food and Agriculture Organization’s (FAO) 2006 report “Livestock’s Long Shadow,” which claims that meat consumption is a bigger contributor to global warming than transportation. Since that report was published, the meat-bashing momentum has snowballed, culminating in one subsequently discredited study claiming that meat consumption was responsible for 51% of all global warming emissions!

If only it were that straightforward. The first problem with the blanket directive to eschew meat is that it characterizes all meat as climate-unfriendly. In fact, the global warming impact of different sources of meat (and dairy) varies widely. According to research published in Scientific American, beef cattle are thirteen times worse for the climate than chickens. And on a calorie-for-calorie basis, chicken meat is responsible for fewer greenhouses gases than plant-based foods like apples, bananas, spinach, and rice.* That means that eating low-impact meats like chicken can actually be better for the climate than eating high-impact plant-based foods. Once you start to compare low-impact meats to highly-processed vegetarian alternatives like tofu, a vegetarian diet can start to look downright irresponsible.

Not only does the meat-bashing movement disregard key distinctions between types of meat, it ignores the effects of producing meat in different ways. Nicolette Hahn-Niman elegantly defends the climate credentials of grass-fed beef in an October 2009 piece for the New York Times, and while I don’t agree with every claim she makes, her main point is valid. When cattle are raised on natural prairies – meaning that no rainforest is cleared to graze them and no grain is grown to feed them, but they simply eat naturally-occurring grasses – they have a relatively small climate footprint. That is, relative to conventionally-raised feedlot cattle. The fact that pasturing beef improves its climate “hoofprint” doesn’t, of course, prove that a diet which includes grass-fed beef is as benign as a vegetarian one (and that’s where I think Niman’s claims are overblown), but it does mean that even beef-eating doesn’t have to be quite the villain it was made out to be.

Finally, focusing on meat-eating as the biggest source of greenhouse gas emissions ignores other food-based sources of emissions that might actually be bigger, but are less-easily quantified. I haven’t been able to track down hard numbers on this, but commentators like James McWilliams in his book Just Food: Where Locavores Get It Wrong and How We Can Truly Eat Responsibly have identified the energy used in food preparation as one of the main contributors to global warming. That means that a burger cooked in a few minutes on the stove might be a more climate-friendly dinner than a (vegan!) pot of rice and beans that requires an hour of simmering. 

So a better slogan than “Stop Eating Meat to Stop Global Warming” might be “Stop Eating Conventionally-Produced Meat from Ruminants, Highly-Processed Foods, Foods Grown on Clearcut Forest and Foods Requiring Substantial Cooking to Stop Global Warming.” Think it’ll catch on?

*Calculated using greenhouse gas emissions per kg food produced for consumption in the UK (http://assets.wwf.org.uk/downloads/how_low_can_we_go.pdf) and calories per 100g food eaten (http://www.keepandshare.com/doc/13243/calories)

Industry: 1. Back-to-nature: 1. And we’re even January 22, 2010

Posted by Angelique in Global warming.
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[Hypothetical debate between technophiliac conventional industrial dairy farmer (Mack) and back-to-nature ex-hippie independent dairy farmer (Meadow) on the most climate-friendly way to raise dairy cattle.]

Meadow: the fact is, cows that eat grass burp and fart less than cows that are forced to eat grain, like your feedlot cattle. So, they release less climate-destroying methane into the air. We need to go back to feeding cows what they were designed to eat: grass.

Mack: Maybe if you hadn’t smoked so much of your cherished grass in the 60s you’d still be able to do math. Your dainty little cows might emit less methane per cow than mine; but when you take into account how little milk each of them produces, it’s not such a bargain. My cows produce so much more milk than yours that it more than outweighs the extra gas they pass. The fact is, my modern dairy machine emits less methane per gallon of milk produced than your old-school farm.

Meadow: What you people never take into account when you trot out this tired line are the greenhouse gas emissions associated with making the grain that your cows eat to become so super-productive. What about the emissions associated with all the fertilizing, tilling, processing and transporting of the grain to your “modern dairy machine?”

Mack: Yeah yeah yeah, everyone knows that those emissions are peanuts compared to the actual animals’ emissions. Are you going to deny that concentrated feed, in the form of enriched grain, increases milk yield and decreases greenhouse gas emissions per gallon?

Meadow: Again, oversimplifying. OK, it is general knowledge that concentrated feed increases yield and reduces emissions (again, not including the emissions from manufacturing and transporting the concentrate). But that’s not the only thing you’re doing over there in your little shop of horrors. You’re also breeding cows for yield and nothing else, and that’s increasing emissions, even on a per-gallon of milk basis.

Mack: Bull. Breeding for higher yield means we can produce all the milk we need with fewer cows, which means a smaller herd and lower emissions, overall and per gallon of milk. Case closed.

Meadow. If only. The problem is, as you well know, that cows bred for high yield are less fertile and less healthy overall. That means you have to engineer a bigger herd because you know that a large proportion of it will be infertile (and therefore won’t produce milk) and will die young due to poor health. My naturally-raised beauties, however, are all happy and healthy down by our little red barn.

Mack: Well, we are always doing more research to maximize the combination of high yield and high fertility. Granted, we’re not there yet, but where are your numbers to show that reduced health and fertility is such a big problem that it outweighs our gargantuan milk yields?

[Cut. Where, indeed, are the numbers? Many quantitative studies of livestock’s greenhouse gas emissions, misleadingly cited by one side or the other in this debate, analyze only one gas (e.g., only methane, only nitrous oxide) or only one source (e.g., only farting, only manure). Many also discuss emissions per animal, but not per unit of output, or do not include the off-farm emissions associated with inputs like fertilizer or cattle feed. One excellent 2006 study,* however, quantifies all these factors for pastured dairy cattle, and concludes that we can minimize GHG emissions by feeding generous amounts of concentrate (grain) to cattle that are bred for medium- (not high-) yield. While this study only analyzes pastured dairy cattle, these strategies also apply to feedlot dairy cattle in the US. What does it mean? From a climate perspective, the conventional dairy industry gets kudos for feeding cows grain instead of just grass, but the back-to-nature folks are right that conventional breeding for high yields is bad news. Looks like each side has something to learn from the other.]

*Lovett et al, “A Systems Approach to Quantify Greenhouse Gas Fluxes from Pastoral Dairy Production as Affected by Management Regime,” Agricultural Systems 88 (2006): 156-179.

Grass-fed: something to chew on January 15, 2010

Posted by Angelique in Animal welfare, Global warming.
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My article for Simple, Good, and Tasty says grass-fed beef may not be all it’s cracked up to be. The best solution, as always, is to know your rancher.

Correction November 24, 2009

Posted by Angelique in Global warming.
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One correction to my previous post Munching your way to a hotter climate? The emissions from flying were incorrect and have been updated from 1.7 tons to 1.1 tons. All the data on eating stayed the same. Thanks to my friend Eric for the catch!

Climate chicanery October 30, 2009

Posted by Angelique in Global warming.
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More fodder for global warming skeptics comes from a report by two World Bank affiliates in the November-December issue of World Watch. The article, “Livestock and Climate Change,” does not deny the reality of global warming or the role of livestock in accelerating it, as presented in the 2006 UN Food and Agriculture Organization’s report Livestock’s Long Shadow. Rather, authors Goodland and Anhang assert that the UN FAO report, which is the definitive study of this topic, understates the volume of livestock greenhouse gas (GHG) emissions by a whopping 400%. Which makes the climate change researchers at the FAO – and people like me who have relied on their analysis – look like idiots.

But if the FAO report really is massively wrong, out the truth must come, regardless of the resulting damage to the credibility of climate research. So, are Goodland and Anhang courageously exposing a botched analysis, or disingenuously furthering the anti-meat cause with a botched analysis of their own?

First, the sniff test. Goodland and Anhang’s revised GHG estimates imply that livestock are responsible for 51% of anthropogenic global warming! Really, with all our heavy manufacturing in industries from construction to apparel? And all the clever ways we move without actually moving, from elevators to 747s? And all the heating and air conditioning that leaks out our doors and windows? And the long showers and the dishwashers? And (let’s not forget) all that breathing we do? Over half of our emissions come just from livestock? Intuition is not in Goodland and Anhang’s favor.

But let’s dig into the science. Their first point is that the FAO estimates don’t include livestock breathing as a source of CO2 emissions. True, and the FAO isn’t as clear as it could be on why they shouldn’t be included. Stephen Walsh provides an accessible explanation: “the normal fate of a plant is to make way to new plants by dying, decaying and releasing the carbon it absorbed from the atmosphere back to the atmosphere mostly as CO2.  Whether the release of CO2 is facilitated by a large animal’s digestive system or by insects and bacteria in the soil doesn’t matter.” In other words, livestock breathing is just one way plants release carbon in their normal life cycle. If the livestock didn’t exist, plants would do it on their own. (Here is Walsh’s full analysis.)

And if you did think that livestock breathing emissions should be added back into total emissions, you should also add human breathing emissions back in. So when Goodland and Anhang conclude that livestock emissions are 51% of anthropogenic emissions, they are conveniently neglecting another major source, thereby incorrectly inflating the proportion that comes from livestock.  

Next the authors tackle land use. They acknowledge that the FAO counts emissions from converting land from forest to livestock use, but say the estimate is too low because it doesn’t count emissions from all the pre-existing land used to support livestock, which could instead be used to grow climate-friendly biofuels. That’s like saying we should count my bathroom floor as a GHG emitter, because I’m not currently growing biofuels on it. Nutty.

Then the authors get into the tricky business of trying to figure out how to appropriately convert units of methane, which is a GHG released by livestock as they burp, fart, and poop, to CO2-equivalent units. (Emissions of different gases have to be converted to CO2-equivalent units so they can be added together to get a picture of total emissions.) Methane is a far more potent GHG than CO2, but CO2 lasts much longer in the atmosphere. Therefore, the shorter the timeframe you choose to analyze, the worse methane emissions look relative to CO2. Goodland and Anhang suggest that instead of using the 100-year timeframe proposed by the FAO, we analyze emissions over 20 years. This triples how bad methane emissions look once they’re converted to CO2-equivalent units. Here, neither the FAO nor the authors is correct, and neither is incorrect. The choice of timeframe is subjective – if you’re interested in short-term effects of emissions, you’ll choose a shorter timeframe, and if you’re interested in impact over several generations, you’ll choose a longer timeframe. Certainly it’s disingenuous to suggest, as the authors do, that the FAO understates emissions. The FAO is just studying a longer timeframe.

Then the authors have the nerve to avoid recalibrating methane emissions from non-livestock sources as they did for livestock, saying it requires “further work.” So, just as they did with livestock breathing emissions, they inflate livestock methane emissions but conveniently neglect to inflate non-livestock methane emissions. Then of course the percent of emissions from livestock looks astronomical.

Finally, the authors have a catch-all “other” category for miscellaneous emissions they claim the FAO understates. The rationale for increasing the estimates of these “other” categories is often that the FAO is using old information – from the 1990s and early 2000s, mostly. But we know that livestock inventories have increased since then, so we know livestock emissions must have increased too, the authors argue. Yes. And, I would add, we also know that the Chinese are driving a hell of a lot more cars, so emissions from the automotive category should increase. And flying more, and consuming more imported designer clothes… Again, if you’re going to increase livestock emissions to more accurately capture what’s happening in the year 2009, you have to increase all these other categories of emissions as well. But Goodland and Anhang don’t, and that’s why they come up with the eyeball-popping and totally false conclusion that over 50% of current GHG emissions come from livestock.

In sum, we already knew that eating meat was a big driver of global warming. No need to bolster the case with inflated numbers and trumped-up analysis. But thanks, Goodland and Anhang, for making climate change research an easy target for all those naysayers out there.

Even happy cows poop October 16, 2009

Posted by Angelique in Global warming.
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Thousand Hills Cattle Company is huge on the Minneapolis organic/local/sustainable food scene. If you’ve been here and eaten any part of a cow at one of those restaurants whose menu lists where its food comes from, it was probably from Thousand Hills. The company distributes beef from Upper Midwest family farms which pasture their cattle for their entire lives, contrary to the conventional industrial practice of “finishing” them in confined feedlots. At a recent screening of the movie Fresh, the owner, Todd Churchill, gave a speech about why he’s such a proponent of keeping cows on pasture.

Todd extolled the many virtues of pastured beef for human health, animal welfare, and the environment. It’s hard to argue with his view that raising animals on pasture is better than keeping them in confinement, but one of his claims struck me as a bit disingenuous. “Who has heard,” he asked, “that you should be a vegetarian if you care about global warming?” Several people in the audience, including myself, raised their hands. “Well,” said Todd thoughtfully, “that’s true if you’re talking about industrial cattle production. But what’s the energy source for my farmers’ cattle?” An audience member dutifully raised his hand and called out: the sun. “Yes,” said Todd, “that’s right – we feed our cows on grass that uses the sun’s energy. We don’t fertilize and till grain. We use almost no tractors.“ So, the implication was, if you just stick to grass-fed beef you avoid all those nasty chemicals and pollutants that are cooking the earth. No need to give up those burgers.

Is it true that eating pastured beef is just as good, from a global warming perspective, as being a vegetarian? Well, if the aspects of beef production that cause global warming are the fertilizer and tractors that go into it, then eliminating them would make eating beef climate-friendly. If not, we have a problem.

Here’s the breakdown of the sources of livestock emissions from the UN Food and Agriculture Organization’s 2006 report Livestock’s Long Shadow.*

P10 16 09 for blog 

Houston, we have a problem. Turns out only about 4.5% of livestock greenhouse gas emissions come from fertilizers and on-farm fuel use (e.g., to run tractors). The biggest portion – over 35% – is due to deforestation and desertification, which happens when forest or other virgin land is cleared to provide space to graze animals. Now, to be fair to Todd, if the farmers he works with are using existing grassland rather than clear-cut forests to graze their cattle, they aren’t contributing to greenhouse gas emissions in that way. So add that to the savings from forgoing fertilizer and tractors and they are cutting emissions about 40% by raising cattle on grass.

But two other categories of emissions kind of smack you in the face when you look at that UN pie chart – the emissions from manure (pooping) and enteric fermentation (burping and farting). No, this isn’t the burping and farting that the guys on the tractors do while they’re bouncing along the prairie; this comes from the animals and as such is not eliminated in Todd’s world of happy cows on pasture. Again, I’ll give him the benefit of the doubt and shave 9% off because certain emissions happen when poop that’s been deposited on the ground gets leached or eroded away, and according to the UN that’s negligible for grassland. So Todd has saved 49% of emissions farming his way, which leaves 51% of livestock emissions still there, even in his relatively clean system. His cows may be happy, but they still poop. Score one point for the vegetarians.

*Pie chart is from UN FAO as quoted in McMichael, Powles, Butler, and Uauy, “Food, Livestock Production, Energy, Climate Change, and Health,” The Lancet 370 (October 6, 2007): 1258. Information is for all livestock, not just cattle, but cattle are worse than average emitters of greenhouse gases. Therefore using these numbers understates their emissions.

Munching your way to a hotter climate? October 8, 2009

Posted by Angelique in Global warming.
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There’s never any good news about climate change. Not only is it always getting worse – happening faster than we’d thought, wreaking unimagined levels of havoc – but everything we do seems to contribute to it. Why bother changing your light bulbs when your daily commute could illuminate your whole neighborhood? And if you thought driving a car was bad – well, you could drive clear across the planet with the greenhouses gases your Thanksgiving flight home will release. And flying is nothing compared to the damage you’re doing every time you eat a burger!

Reasoning that everything can’t literally be worse than everything else, I did a little research and composed a ranking of our actions’ impact on greenhouse gas emissions, and where meat-eating falls on that list. This ranking is rife with assumptions, but see the chart below for my best shot at the average person’s annual CO2 emissions from various sources.

The greenhouse gas savings from replacing the average US diet with a vegan diet are pretty significant, but it’s even better to leave the Suburban in the garage.

NOTE: The emissions for flying have been corrected; in the initial version of this graph, they were listed as 1.7 tons. (11/24/09)

Sources

Diet and cars: Eshel and Martin, “Diet, Energy, and Global Warming,” Earth Interactions v.10 n.9 (2006)

Light bulbs: Fat Knowledge

Air travel: Gallup Poll 12/06 cited in Uclue and Terrapass Carbon Footprint Calculator

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