Book Review: The Global Climate and a Defense of Beef

Now for the other side of the argument. In this second of my series of three reviews of books and movies, I’ll consider a book that presents a spirited defense of beef. In fact, that’s its title: Defending Beef, by Nicolette Hahn Niman.

The book paints a picture of a better beef system, less damaging to the climate and the environment generally than the current system is. This is a vision I applaud, and one that my colleagues in the UCS Food and Environment program are researching. However, the book also raises scientific issues that I feel are worth exploring, since the dominant beef production system we have in place today, both globally and domestically, has some real problems.

As in the previous review, my focus will be on beef’s effect on the climate, which is the part of the subject that I know best. But I should mention that Hahn Niman’s book covers several other aspects—e.g. water, biodiversity, overgrazing, and especially health and nutrition. These are certainly concerns of mine and also aspects on which several of my UCS colleagues are working.

Chapter 1 of the book is titled “The Climate Change Case against Cattle: Sorting Fact from Fiction,” and it responds to a pattern that scientists have repeatedly found—that the climate footprint of beef is much larger than for nearly every other food, including other kinds of meat. This is not only the case globally, but for the United States as well. Thus, cattle are by far the largest source of U.S. emissions from agriculture, as shown by the graph below:

How significant are beef emissions?

Hahn Niman doesn’t defend the current agricultural system that is producing these levels of emissions. However she focuses her critique on the 2006 FAO report Livestock’s Long Shadow and its estimate that 18% of global emissions are due to livestock, a large majority of which is due to beef. This is despite the more recent scientific studies that have confirmed and reinforced its basic conclusions, with only small changes in the percentage. These changes have come about because newer data became available and, importantly, because fossil fuel emissions—the major component of the denominator of the percentage—have grown. Thus, a decade later, the overall story of Livestock’s Long Shadow has been confirmed and extended by more evidence.

U.S. beef production, consumption and deforestation

Two of Hahn Niman’s most important points concern the relevance of deforestation caused by livestock to Americans, and failing to consider the “offsetting” of beef’s emissions by the sequestration of soil carbon. So let’s consider those in turn.

Hahn Niman says that when considering the climate impact of beef, “including deforestation from developing countries … is unfair and unreasonable” (page 45). She claims that “I’ve shown that American beef has virtually no connection to deforestation emissions” (page 23). Thus, the issue with U.S. beef seems to be whether deforestation, an important source of global warming pollution (about 10% of the global total, by recent estimates) has anything to do with the U.S. While this is true of US beef production, it misses the important point that American beef is part of a global market and US beef consumption does play a role in deforestation:

Four relevant points:

1)     While the majority of beef consumption in the U.S. is produced domestically, we most definitely import appreciable quantities from tropical forest countries.

2)     That is because the beef market is now clearly a global one, in which increased consumption in any country, including the U.S., raises total demand and thus drives up world prices. And higher beef prices have been shown to lead to more deforestation. The U.S. is the world’s leading consumer of beef—24.1 billion pounds in 2014, according to the USDA.

3)     U.S. companies are an important part of the global beef trade, as explained in UCS’ recently updated web pages on the drivers of deforestation today. This gives Americans an opportunity as well as a responsibility. We can let our corporations know that we want them to act to eliminate beef-driven deforestation from their supply chains—not just those in the U.S. but everywhere in the world—just as we have done with deforestation driven by palm oil.

4)     Finally—and this is a criticism of our political leaders, not of Hahn Niman’s argument—we already have a long and sad experience of refusal to act on climate change, using the excuse that other countries are equally or more guilty than we are and therefore have to act first. This applies to all the causes of global warming—including deforestation.

Can U.S. beef be climate neutral?

A substantial part of Hahn Niman’s argument on the potential for carbon sequestration in pastures—11 pages—is based on the theories of Alan Savory, the former Zimbabwean rancher now famous for his TED talk. There have been detailed and extensive critiques of Savory’s arguments, both on the web and in scientific journals, so I won’t repeat all their points here. But just add one that to me is quite telling: after many years of controversy, Savory still has not published his studies on carbon sequestration in peer-reviewed scientific journals or made his data available publicly so that other researchers can assess it. This is particularly important since he is claiming to have made such a striking discovery. This omission alone weakens his case—and thus Hahn Niman’s use of his theories—very significantly.

What about carbon sequestration more broadly? Hahn Niman argues that it “may be more than enough to completely offset the emissions from grazing animals.” (page 45). How much evidence is there for this?

Zhongmin Hu and colleagues, in a 2016 article in Global Change Biology, reviewed experiments excluding grazing animals from grasslands at 51 different sites in China. They found that grazing exclusion led to an increase in carbon, both in the soil and in the vegetation, at most of the sites. In other words, they found that the carbon stock was higher without the grazers. This is in the opposite direction of the kind of effect that Hahn Niman’s “offsetting” argument assumes.

The same result—an effect on ecosystem carbon, but in the wrong direction for the hypothesis, comes from a large review of biomass and carbon recovery at 45 sites, with about 1500 total plots, in the New World tropics. In this study by Lourens Poorter and colleagues, both pastures from which cattle had been removed and abandoned agricultural fields showed substantial increases in biomass and carbon stock, with the annual rate of increase in carbon averaging 3.05 tons per hectare (1.23 tons per acre). There was no significant difference between former fields and former pastures in the rate of recovery of carbon.

So, the existing evidence doesn’t show that the difference in sequestration with and without cattle leads to a net carbon sink. Also, it remains unclear to what degree the total direct emissions from animals (ruminant methane, manure, etc.) and indirect ones (e.g. deforestation, fertilizer used to produce feed grains, etc.) could be offset through best management practices (e.g., by soil carbon sequestration in grasslands, avoided conversion to rangelands, avoiding chemical fertilizers, etc.)

This is not to say that we shouldn’t be working hard to increase soil sequestration in pastures, as well as under agricultural fields. And indeed, there have been some promising results in this kind of research. For example, Teague et al. recently proposed a set of scenarios for North American beef production, involving reduced soil erosion through conservation cropping and “adaptive multipaddock grazing” (AMP), under which net emissions could be decreased significantly Likewise, I have colleagues at UCS modeling various agricultural scenarios that will add to our knowledge on this question. But for now, whether or not beef production could ever become carbon neutral is far from settled science.

The reality of beef today

While I state at the outset that Hahn Niman does not defend current beef production practices, it is instructive to look at the current situation. Beef’s much higher emissions are associated with much more use of water and much more need for land. The figure below, from a recent review by Raganathan et al. published in a chapter in IFPRI’s annual report and also as a separate report from the World Resources Institute, shows the size of these differences.

How do we solve the problem?

Changing what we eat is one of the steps that we can take to confront this challenge, but it is not “the solution.” This is not only because emissions related to beef, although significant, are still considerably less than those from fossil fuels. It’s also because the necessary transformation of diets needs to recognize that the consumption of foods from high-emissions, ecologically inefficient production systems varies enormously between countries. It’s in the Americas—both North and South—and to a lesser extent in Russia and Europe that beef consumption rates are highest, and thus where emissions could be cut the most by diet changes.

A final point, is that this is a matter of reducing emissions, not an all-or-nothing question of morality. Personally, I have tried to reduce my emissions over the past decade by making changes such as driving a hybrid car, using public transport whenever possible, and changing our home’s electricity supplier to one that provides 100% renewable energy. These reduce my carbon footprint, but they don’t make it zero. Similarly, I now eat beef less frequently and in smaller amounts, but I haven’t eliminated it from my diet entirely.

There’s a real irony in this, because Nicolette Hahn Niman doesn’t eat beef—in fact, she doesn’t eat meat at all. She explains (page 184) that having given up meat in earlier years when she became a vegetarian, “to date I simply have not had the urge to eat it. If I ever regain the desire to eat meat, I will.”

So, a defender of beef doesn’t eat it, while this critic of it does. I don’t see this as making either of us more ethical than the other. But I do admit that it very likely means that my emissions from what I eat are probably larger than hers.

In my final review of this series on the book Cowed, I’ll consider how we can move towards reducing such emissions, but will also argue that beef consumption should continue, although at a lower level in many countries, including the U.S. Here I have looked at data showing the impact of removing grazing, because it’s a key test of the offsetting hypothesis, not because that’s my policy recommendation. Testing a hypothesis is one thing, and science gives us some a basic method for how to do it. But using that method—comparing “with” and “without”—is quite different from considering how to change beef production and consumption systems in the future.

What’s most important, though, is not just changing our individual carbon footprints, but doing things to change the overall emissions and sequestration of the whole planet. For example, if we could get American companies to insist that the beef and other products that they source from the tropics are deforestation-free, it would have much more impact than simply reducing our own consumption. These kinds of changes will help move our global society towards ways of eating, ways of farming and ranching, and ways of living, that will create a better future for those with whom we share the Earth.