The organic dilemma

As I observed last week, I've been trying over the past couple of months to make my diet lighter on the earth. After reading a study back in October arguing that eating less meat and dairy was the single best way to shrink your total ecological footprint, I've eliminated milk from my everyday eating, and I'm now working on finding alternatives to cheese. And Brian has started habitually making more of our everyday meals vegan when he can, using substitutes like flaxseeds and water in place of eggs.

So you might think that, while I'm at it, I should also be making a point of eating more organic food, right?

Well—maybe not.

My doubts about organic food began last summer. That's when I listened to an episode of "Science Versus," a podcast that explores the science behind controversial issues of the day, called "Science Versus Organic Food." At the outset, chipper host Wendy Zukerman announced that she would be addressing three specific questions about organic food: does it taste better, is it better for you, and is it better for the planet?

I figured I wouldn't learn much of anything new from this podcast, since I was already pretty confident that the answers were no, mostly no, and yes. I listened impatiently through the first half of the podcast, as Zukerman revealed that people can't tell organic tomatoes from conventional ones in blind taste tests, that there's no evidence organic food contains more nutrients, and that there's no difference in cancer rates between people who eat organic food regularly and those who don't (although there is evidence that the workers who pick the conventionally grown food suffer higher rates of cancer). All this was old news to me, and also, I felt, beside the point. I was waiting to hear the evidence explaining why organic food was better for the environment—lower water use, lower carbon emissions, less damage to wildlife, etc., etc.

At first, it looked like the second half of the podcast was going to confirm these views, as Zukerman cited a study showing that organic farms have better soil health than their conventional counterparts. But then things took a turn for the worse as she started exploring the question of pollution. She pointed to studies showing that one of the main types of pollution associated with farming, nitrogen runoff from the soil, was actually worse on organic farms, which rely on slow-release organic fertilizers like manure rather than chemical fertilizers that can be carefully timed and measured to release nitrogen just when it's needed. And then she followed this up with the real kicker: since organic farms have lower overall yields than conventional ones, making more of our food supply organic will divert more land from other uses, while also producing still more of this harmful runoff. (She did concede that if the shift toward organic were accompanied by a shift toward vegetarianism, we could feed the world organically without using more land. But just buying organic won't necessarily help make that happen.)

Hearing this threw me for a bit of a loop, but I quickly rallied. After all, there was no reason to take this one half-hour podcast, which necessarily can't cover any topic in all that much detail, as the final word on the subject. I knew it had left out one of the main reasons I'd always had for choosing organic over conventional food, a lower carbon footprint. And while it had discussed pollution from nitrogen runoff, it hadn't mentioned the environmental impacts of all those nasty pesticides and herbicides used on conventional farms. Clearly it was worth taking little time to look into these issues on my own before just deciding to drop organic food altogether.

So I did a little Googling, making sure to focus on the most reliable sources I could find. But to my shock and dismay, these sources generally seemed to come down on Zukerman's side of the argument. For instance, a highly detailed analysis of organic versus conventional farming in Environmental Research Letters concluded that "per unit of food, organic systems require more land, cause more eutrophication, use less energy, but emit similar greenhouse gas emissions (GHGs) as conventional systems." Even the environmental site Treehugger was forced to admit the validity of this study, though the author argues that "surely there are other reasons why Earth-friendly food production is a good idea" aside from carbon footprint.

That might be true, if organic farms really were more "Earth-friendly" in other ways. But the studies I found just don't seem to back up that conclusion. A piece from the Genetic Literacy Project noted that the rules for organic labeling often prevent organic farmers from following the most sustainable practices—for instance, blocking them from "using state-of-the-art soil building practices" and forcing them to rely on "older, ‘natural’ less targeted chemical pesticides" that can cause more collateral damage to beneficial insects. And an article in the Guardian pointed out that "for every acre increase in certified organic farmland there was an increase in greenhouse gas emissions from agricultural production in the United States." (The author argued that organic farms could have a lower carbon footprint than conventional ones, but the current standards give them no real incentive to do so.)

So what does this all mean? If I really want my diet to be as low-impact as possible, does it make sense to drop organic foods from my shopping list entirely?

Well, again—maybe not.

You see, as I've explained before, I don't always buy organic. I insist on it for only a few products—the ones that are most damaging to the environment when grown conventionally, including coffee, sugar, and bananas. The studies that conclude conventional farming is less damaging than organic farming are looking at agriculture as a whole, not at these specific crops. So until I see evidence to the contrary, it seems reasonable to continue to assume organic versions of these are less harmful, and shop accordingly.

As for the rest of the food I buy, I go by cost. I will buy the organic version of a product if its price is no more than 50 percent higher than the conventional versions. (I used to allow a markup of 60 percent, based on a study I'd seen that said this was the average price premium for organic foods. Hence, I concluded that if the markup was under 60 percent, it was a good deal. However, in 2015, Consumer Reports looked at over 100 foods and found that the organic ones, on average, cost only 47 percent more than their conventional equivalents. So I switched my "Rule of 1.6" down to a "Rule of 1.5," which also has the advantage of making the math easier.)

Now here's the thing—the biggest problem with organic food, and the biggest reason its carbon footprint can be higher than conventional foods, is that it requires more land to grow the same amount of food. This is also why the price difference for some organic foods, like grass-fed beef, is often so ridiculously high. But as Consumer Reports found, there are other organic foods for which the price difference is much lower, or even nonexistent. And it stands to reason that these cheaper organics must also be cheaper to grow—which means they probably also use less land. And if that's true, then the cheaper an organic product is compared to the conventional version, the more eco-friendly it's likely to be.

I admit I can't really prove this theory, since most studies comparing the environmental impact of organic versus conventional foods don't break it down by specific crops. However, I found one piece at the Genetic Literacy Project that shows the "yield gaps" between organic and conventional versions of specific crops, and there seems to be some correlation between those figures and the price differences between the corresponding foods shown in this Business Insider article. For instance, tomatoes, which have a yield gap of 61 percent, have a price gap of 50 percent; avocados, with a yield gap of only 12 percent, have a price gap of about 12 percent as well; almonds have a yield gap of 43 percent, and almond butter has a price gap of 35 percent. It's not perfect, but there's at least a hint of a pattern there.

So all in all, it looks like what I always thought was the organic dilemma—that doing the right thing for the earth was more costly—is exactly backward. Instead, if you let price be your guide about when to buy organic, you'll end up making the right choices for both the planet and your wallet. In other words, buying organic, which I thought of as one of the few exceptions to the rule that ecology and economy go together, actually turns out to be a perfect example of it.