Adaptation to Climate Change

I ran across this fascinating paper by Richard Sutch on the the relationship between the Dust Bowl and hybrid corn adoption.  The discussion is interesting in light of current discussions bout how and whether farmers will be able to adapt to climate change and whether technology development can help mitigate some adverse effects.

Here's a passage from Sutch.

“The suggestion that I make in this chapter is that the severe drought of 1936 revealed an advantage of hybrid corn not previously recognized— its drought tolerance. This ecological resilience motivated some farmers to adopt hybrids despite their commercial unattractiveness in normal years. But that response to climate change had a tipping effect. The increase in sales of hybrid seed in 1937 and 1938 financed research at private seed companies that led to new varieties with significantly improved yields in normal years. This development provided the economic incentive for late adopters to follow suit. Because post- 1936 hybrid varieties conferred advantages beyond improved drought resistance, the negative ecological impact of the devastating 1936 drought had the surprising, but beneficial, consequence of moving more farmers to superior corn seed selection sooner than they might otherwise.”

This long quote is from the conclusions and is well worth reading.

“The sociologists Bryce Ryan and Neal Gross, writing in 1950, studied the diffusion of hybrid corn in two communities located in Greene County, Iowa (Ryan and Gross 1950). In their view, late adopters were farmers bound by tradition. They were irrational, backward, and “rural.” The early adopters by contrast were flexible, calculating, receptive, and “urbanized.” “Certainly,” they summarized, “farmers refusing to accept hybrid corn even for trial until after 1937 or 1938 were conservative beyond all demands of reasonable business methods”. They drew a policy implication: “The interest of a technically progressive agriculture may not be well served by social policies designed to preserve or revivify the traditional rural- folk community”. In part, this view was based on Ryan and Gross’s (incorrect) belief that hybrid corn was profitable in the early 1930s. I have suggested that this was not the case. Figure 7.11 should also give pause to the view that rural laggards delayed the adoption of hybrid corn. It would be hard to argue that the farmers in Iowa Crop Reporting District 6 were predominantly forward-thinking leaders, attentive, and flexible, while those in Indiana and Ohio were predominately backward rustics trapped by inflexible folk tradition.

I think an implication of this study is that farmers (even those of rural America in the 1930s) are remarkably resilient and adaptive. Sudden and dramatic climate change induced a prompt and prudent response. An unexpected consequence was that an otherwise more gradual process of technological development and adoption was given a kick start by the drought and the farmers’ response. That pushed the technology beyond a tipping point and propelled the major Corn Belt states to the universal adoption of hybrid corn by 1943. The country as a whole reached universal adoption by 1960.”

The paper has a number of interesting discussions about the role of the USDA, federal research, and strong personalities that pushed along the development of hybrid corn.  For more on the history of the development of hybrid corn, see this previous post.

Lab grown meat

Quartz.com just ran a piece taken from one of the chapters of Unnaturally Delicious on lab grown meat.  Here's the start:

“On Aug. 5, 2013, Mark Post went out to grab a hamburger. This was no drive-through Big Mac. Rather, Post bit into his $325,000 burger in front of an invitation-only crowd of journalists, chefs, and food enthusiasts in the heart of London.

The strangest part wasn’t the cost or the crowd but the meat. Post, a professor of vascular physiology at Maastricht University in the Netherlands, grew the burger himself. Not from a cow on his farm, mind you, but from a bovine stem-cell in a petri dish in his lab. Post’s research, partially funded by Sergey Brin, one of Google’s co-founders, has the potential to upend conventional wisdom on the environmental, animal welfare, and health impacts of meat eating.

Ironically enough, I first met Post at a meeting of some of the world’s largest hog producers. ”

The Quartz editors left out what I think is one of the most important points made in the chapter about relative inefficiencies of meat eating.  So, for sake of completeness, here's the segment they left out (long time readers will recognize that I've touch one this theme in previous blog posts).

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More broadly, this line of argument – that meat production (inside the lab or out) is “wasteful” because it requires feed inputs that humans might use – is misplaced.  To see this, it is useful to consider a thought experiment – an imaginary story that might help us get to the bottom of things. 

Imagine a biologist on an excursion to the Amazon looking for new plant species.  She comes across a new grass she’s never before seen, and brings it back home to her lab.  She finds that the grass grows exceedingly well in greenhouses with the right fertilizer and soil, and she immediately moves to field trials.  She also notices that the grass produces a seed that is durable, storable, and extraordinarily calorie dense.  The scientist immediately recognizes the potential for the newly discovered plant to meet the dietary demands of a growing world population.

But, there is a problem.  Lab analysis reveals that the seeds are, alas, toxic to humans.  Despite the set-back, the scientist doesn’t give up.  She toils away year after year until she creates a machine that can convert the seeds into a food that is not only safe for humans to consume but that is incredibly delicious to eat.  There are a few downsides.  For every five calories that go into the machine, only one comes out.  Plus, the machine uses water, runs on electricity, burns fossil fuels, and creates carbon emissions. 

Should the scientist be condemned for her work?  Or, hailed as an ingenious hero for finding a plant that can inexpensively produce calories, and then creating a machine that can turn those calories into something people really want to eat?  Maybe another way to think about it is to ask whether the scientist’s new food can - despite its inefficiencies (which will make the price higher than it otherwise would be) - compete against other foods in the marketplace?  Are consumers willing to pay the higher price for this new food? 

Now, let’s call the new grass corn and the new machine cow. 

            This thought experiment is useful in thinking about the argument that corn is “wasted” in the process of feeding animals (or growing lab grown meat).  Yet, the idea that animal food is “wasted” is a common view.  For example, one set of authors in the journal Science wrote,

“Although crops used for animal feed ultimately produce human food in the form of meat and dairy products, they do so with a substantial loss of caloric efficiency. If current crop production used for animal feed and other nonfood uses (including biofuels) were targeted for direct consumption, ~70% more calories would become available, potentially providing enough calories to meet the basic needs of an additional 4 billion people. The human-edible crop calories that do not end up in the food system are referred to as the ‘diet gap.’”

The argument isn’t as convincing as it might first appear.  Few people really want to eat the calories that directly come from corn or other common animal feeds like soybeans.  Unlike my hypothetical example, corn is not toxic to humans (although some of the grasses cows eat really are inedible to humans), but most people don’t want to field corn.    

So if we don’t want to directly eat the stuff, why do we grow so much corn and soy?  They are incredibly efficient producers of calories and protein.  Stated differently, these crops (or grasses if you will) allow us to produce an inexpensive, bountiful supply of calories in a form that is storable and easily transported. 

The assumption seems to either be that the “diet gap” will be solved by convincing people to eat the calories in corn and soy directly, or that there are other tasty crops that can be widely grown instead of corn and soy which can produce calories as efficiently as corn and soy.  Aside from maybe rice or wheat (which also require some processing to become edible), the second assumption is almost certainly false.  Looking at current consumption patterns, we should also be skeptical that large swaths of people will want to voluntarily consume substantial calories directly from corn or soy.

What we typically do is take our relatively un-tasty corn and soy, and plug them into our machine (the cow or pig or chicken, or in Post’s case the Petri dish) to get a form of food we want to eat.  Yes, it seems inefficient on the surface of it, but the key is to realize that the original calories from corn and soy were not in a form most humans find desirable.  As far as the human pallet is concerned, not all calories are created equal; we care a great deal about the form in which the calories are delivered to us.

The grass-machine analogy also helps make clear that it is probably a mistake to compare the calorie and carbon footprint of corn directly with the cow.  Only a small fraction of the world’s caloric consumption comes from directly consuming the raw corn or soybean seeds.  It takes energy to convert these seeds into an edible form – either through food processing or through animal feeding.  So, what we want to compare is beef with other processed foods.  Otherwise we’re comparing apples and oranges (or in this case, corn and beef).

 The more relevant question in this case is whether lab grown meat uses more or less corn, and creates more or less environmental problems, than does animal grown meat.  

How bad, really, is meat eating?

Last week, Scientific American published a piece on how to get people to eat less meat.  Apparently, the science is settled and we now only need to come up  with the right "messages." 

There are an awful lot of apocalyptic pronouncements about the adverse effects of meat eating on the environment.  In a widely viewed TED talk, Mark Bittman likens meat production to a nuclear explosion and says it is leading to a "holocaust of a different kind," pointing directly to impacts on climate change.  As another example, Bill Maher, comedian and host of an HBO talk show, has written, “But when it comes to bad for the environment, nothing—literally—compares with eating meat. . . . If you care about the planet, it’s actually better to eat a salad in a Hummer than a cheeseburger in a Prius.”   I could, quite literally, provide dozens of these sorts of quotes from well known journals, writers, actors, etc, but I think you get the point.  The overall message is pretty clear: we should become increasingly more vegetarian.  

Let's take a look at one of the outcomes people are most worried about and where externality is relatively clear: climate change.   I went to the EPA's calculations, and surmise the following carbon equivalent impacts for the US attributable to beef cattle, swine, and poultry production during the year 2014 (MMT is million metric tons):

• beef cattle: 116.7 MMT C02 (from digestion) + 4 MMT C02 (from waste management) = 119.7 MMT C02;
• swine: 1 MMT C02 (from digestion) + 22.4 MMT C02 (from waste management) = 23.4 MMT C02; and
• poultry: 0 MMT C02 (from digestion) + 3.2 MMT C02 (from waste management) = 3.2 MMT C02.

Elsewhere, the EPA suggests using using a social cost of carbon of $36/metric ton of C02 (assuming a discount rate of 3%) for cost benefit analysis and rule making.  Multiplying the C02 impacts above by the price tag of $36 implies the following total carbon costs in 2014.

• beef cattle: $4.3 billion;
• swine: $842 million; and
• poultry: $115 million.

That seem like a lot, but keep in mind that we also eat a lot of meat.  Data from the USDA suggests that in 2014, farmers/ranchers in the US produced 24.32 billion pounds of beef, 22.86 billion lbs of pork, and 44.98 billion lbs of poultry.  Putting the carbon costs on a per-pound basis (i.e., dividing total carbon cost by pounds produced), suggests the following.

• beef: $0.177/lb;
• pork: $0.037/lb; and
• poultry: $0.002/lb.

I don't know about you, but those don't seem like enormous costs.  Let's think about it a different way.  Suppose you wanted to "internalize" the the impacts you're having on climate change by altering how much beef, pork, and poultry you buy.  To do this, take the price you see at the grocery store and add about $0.18/lb to the price of beef, $0.04/lb to the price of pork, and less than a penny to the price of poultry, and act as if these were the prices actually being charged.  Would you change your behavior much based on such price increase?  If not, we'd could say the climate impacts are relatively small.

I saw the following from the economist Bob Lawson on twitter this weekend.

If you have ever said "externality" but don't understand that the optimal amount of pollution >0, then you're doing it wrong.

— Bob Lawson (@doclawson12) April 17, 2016

The key isn't to have zero greenhouse gas impacts, but rather to to make sure you're taking into account the cost of those impacts.  For the case of beef, that means acting as if the price were about $0.17/lb higher.  Do that and you can shop away, guilt free (well, at least the guilt of carbon impacts).

P.S.  USDA data suggests the retail price of beef in 2014 was around $5.60/lb.  An $0.18/lb price increase would represent about a 3% increase in the price of beef.  Assuming the own-price elasticity of demand is, say, -0.6, this price increase would lead to a 1.9% reduction in the quantity of beef demanded. So, to internalize the carbon impacts of beef eating, Americans would reduce beef consumption by 1.9%.   It's not zero but its a far cry from vegetarianism.  

An often forgotten benefit of biotech crops

Discussions on the environmental benefits (or costs) of genetically engineered crops tend to focus on relative volumes and toxicities of herbicides applied, effects of Bt, and possibilities of cross pollinating native plants.  In so doing, what is often missed is an important environmental benefit of herbicide resistant crops.  In particular, if a farmer can control weeds by spraying the entire field with a herbicide like glyphosate, that means they don't have to use other methods of weed control (like plowing) that may lead to soil runoff.  

A new paper just released by the American Journal of Agricultural Economics by Edward Perry, GianCarlo Moschini, and David Hennessy tackles this issue. Here's a portion of the abstract:

“We find that glyphosate tolerant soybeans and conservation tillage are complementary practices. In addition, our estimation shows that farm operation scale promotes the adoption of both conservation tillage and glyphosate tolerant seed, and that all of higher fuel prices, more droughty conditions, and soil erodibility increase use of conservation tillage. We apply our results to simulate annual adoption rates for both conservation tillage and no-tillage in a scenario without glyphosate tolerant soybeans available as a choice. We find that the adoption of conservation tillage and no-tillage have been about 10% and 20% higher, respectively, due to the advent of glyphosate tolerant soybeans.”

It should be noted that herbicide tolerance isn't unique to biotechnology.  There are several "non GM" crops on the market that are tolerant to certain herbicides but are not genetically engineered, at least as the term normally used.

Consumer Uncertainty about GMOs and Climate Change

A lot of the debate and discussion surrounding public policies toward controversial food and agricultural issues like GMOs or climate change revolves around public sentiment.  We ask people survey questions like "Do you support mandatory labeling of GMOs?"  However, as I've pointed out, consumers may not even want to have to make this sort of decision; they would prefer to defer to experts.  Thus, we're presuming a level of understanding and interest that consumers may not actually have.  This is related to the recent discussion started by Tamar Haspel in the Washington Post about whether the so-called food movement is large or small.  Are "regular" people actually paying much attention to this food stuff that occupies the attention of so many journalists, researchers, writers, and non-profits?

I had these thoughts in mind as I went back and looked at this post by Dan Kahan who took issue with Pew's survey on public opinions about GMOs (this was the survey that attracted a lot of attention because it showed a large gap in public and scientific opinion on GMOs).  Kahan wrote:

“the misimpression that GM foods are a matter of general public concern exists mainly among people who inhabit these domains, & is fueled both by the vulnerability of those inside them to generalize inappropriately from their own limited experience and by the echo-chamber quality of these enclaves of thought.”

and

“That people are answering questions in a manner that doesn’t correspond to reality shows that the survey questions themselves are invalid. They are not measuring what people in the world think—b/c people in the world (i.e., United States) aren’t thinking anything at all about GM foods; they are just eating them.

The only things the questions are measuring—the only thing they are modeling—is how people react to being asked questions they don’t understand. ”

This let me to think: what if we asked people whether they even wanted to express an opinion about GMOs?  So, in the latest issue of my Food Demand Survey (FooDS) that went out last week, I did just that.  I took my sample of over 1,000 respondents and split them in half.  For half of the sample, I first asked, "Do you have an opinion about the safety of eating genetically modified food?"  Then, only for people who said "yes", I posed the following: "Do you think it is generally safe or unsafe to eat genetically modified foods?" For the other half of the sample, I just asked the latter question about safety beliefs and added the option of "I don't know".  This question, by the way, is the same one Pew asked in their survey, and they didn't even offer a "don't know" option - it had to be volunteered by the respondent.  So, what happens when you allow for "I don't know" in these three different ways? 

When "don't know" is asked 1st in sequence before the safety question, a whopping 43% say they don't have an opinion!  By contrast, only 28% say "don't know" when it is offered simultaneously with the safety question.  And, as the bottom pie graph shows, only about 6% of respondents in the Pew survey voluntarily offer "don't know".  Thus, I think Kahan's critique has a lot of merit: a large fraction of consumers gave an opinion in the Pew survey, when in fact, they probably didn't have one when this option was allowed in a more explicitly matter.  

Moreover, allowing (or not allowing) for "don't know" in these different ways generates very different conclusions about consumers' beliefs about the safety of GMOs.  Conditional on having an opinion, the percent saying "generally safe" varies from 40% in the sequential question to 50% in the simultaneous question to 39% in the Pew format which didn't offer "don't know."  That support can vary so widely depending on how "don't know" is asked is hardly indicative of stable, firm, beliefs about GMOs among the general public. 

In last week's survey I also carried out the same exercise regarding Pew's questions on climate change.  For half of my sample, I first asked whether people had an opinion about the causes of changes in the earth's temperature; for the other half, I included "don't know" as an option simultaneous with the question itself.   Here are the results compared to Pew's, which again did not explicitly offer a "don't know."  

Again, we see big differences in the extent to which "don't know" is expressed depending on question format, varying from 37% in the sequential version to only 2% in Pew's survey.  In this case, it appears that people who would have said "don't know" in the sequential question format are more likely to pick response categories that disagree with scientists, when they are given questions where "don't know" isn't so explicitly allowed.  

What can we learn from all this?  Just because people express an opinion on surveys doesn't mean they actually have one (or at least not a very firmly held one).