What if we got rid of all livestock? Would that reduce greenhouse gases? And what would we eat instead?
Those are some of the questions that authors Robin White and Mary Beth Hall tried to answer. To see what would happen they modeled a United States where no livestock existed, and we ate only plant-based diets. Their conclusion, published in their paper, “Nutritional and greenhouse gas impacts of removing animals from US agriculture,” is that the total US greenhouse gas emissions would only be reduced by 2.6% and that this decrease would come at a high cost.
First, with a plant only diet, it would be much more difficult for people to meet their nutritional requirements. Animals are our only non-pill form of calcium, 3 fatty acids, and vitamin B12. Two of these fatty acids reduce heart disease and are critical for the visual and mental development of infants. The authors found that, “Even though it is possible to balance plant- based diets for individual humans, it may be a challenge for these diets to scale well within the US food production system because of the types of crops that can be grown in the available climates and soils.” They pointed out that animals convert energy-dense, micronutrient-poor foods like grain into micro-nutrient dense foods like meat, milk, and eggs, making it possible for the U.S. to meet the population’s nutritional requirements.
We might also have to import more food. Current U.S. fruit and vegetable consumption is 203% and 164% of what we produce domestically. The authors point out that given this high demand, if it was viable to produce more of these high-value crops in the U.S., it would already be occurring. They concluded that limitations on production may be a result of suitable land, climate and infrastructure to grow these crops.
According to the authors, we’d face other challenges as well in a no-livestock world. Assuming we kept our pets, how would we replace the almost 1.5 billion pounds of protein and almost 300 million pounds of fat we need to feed our cats and dogs every year? How would we get rid of the inedible vegetable waste that we currently feed to animals? We’d also have to produce more synthetic fertilizers to replace animal manures. Finally, with no animal agriculture, 1.6 million people would need to find new jobs, and we’d need to replace a $32 billion hit to our exports.
One of the reasons for suggesting getting rid of livestock is their role in greenhouse gas emissions. Past models of a shift to a plants-only diets have shown reductions in a household’s carbon footprint when people ate less meat. But these Life Cycle Assessments did not consider all the changes that White and Hall realized would have to be made in the food system as a result. That’s why their numbers have come out so differently.
In the end, after subtracting out greenhouse gas emissions for livestock, and adding in increases to synthetic fertilizer production, disposal of inedible waste, and changes in land use, agricultural emissions were reduced from 622.6 CO2 equivalents to 446. Since agriculture makes up only 9% of U.S. greenhouse gas emissions, this change meant a reduction of only 2.6% in total U.S emissions.
Based on their results, White and Hall concluded, “Overall, the removal of animals resulted in diets that are nonviable in the long or short term to support the nutritional needs of the U.S. population without nutrient supplementation.” They recommend that any discussion of our food system should include the kinds of direct and indirect effects they considered in their paper so we can properly evaluate impacts of potential changes.
Thanks to Jon Previant for inspiring us to follow up on this article!
I’m only a few paragraphs into the article, and this quote alone impunes its credibility: “Animals are our only non-pill form of calcium, 3 fatty acids, and vitamin B12. ” Calcium–and in its optimally-absorbable form–is found in leafy greens, cruciferous vegetables (and many other vegetables) and is found most abundantly in seseame seeds. Plant-based calcium is far more absorbable than dairy calcium, and its absorption involves no bone loss–as does dairy calcium. Essential fatty acids are ALL in plants, especially walnuts, flax seeds, leafy greans, other nuts and seeds and legumes. People who eat meat can be B12 deficient. Pill forms of B-12 are bacteria-grown. This is basic nutritional science.
Did this study include Bison, Elk, Deer and Pronghorn? Would the animal haters want to destroy them also; and, if not, who out there thinks they would not fill the void left by the removal of domestic animals?–at least partially.
Hello Burke,
This study included livestock only. In addition, I think it’s unfair and unkind to classify people asking these questions as “animal haters.” Rather, people everywhere are asking questions about how we manage our food system and the livestock that are part of that and what kind of environmental impacts we need to consider. I think that asking these questions is important and we should be thoughtful in our responses. As to your question about whether other animals might fill the void left by the removal of domestic animals, as the scientists in this study noted, they only studied one aspect of this large system and there are other things to consider. There are always more and more questions.
I guess I’m one who questions whether our wild ungulates would take up the eco-niche if we remove cattle from the equation. In the western half of the US we have tremendous amounts of non-tillable land that provides habitat for deer, elk, antelope and other species. Some of this land is privately held, some public. Replacing cattle with a similar biomass of wild species would be extremely challenging, and the conflict with humans would be intense. Beyond the carnage on the roads, the idea of our Wildlife agencies allowing a 10 or 100 or 1,000-fold increase in elk and deer numbers seems highly unlikely to me. Wildlife is viewed as a financial asset by our wildlife agencies, and our government sells tags and licenses in order to maintain specific populations. I believe the conflict caused by massive herds of wildlife would simply result in increased pressure to control those populations.
Thinking back to old National Geographic films showing huge population of ungulates in Africa, you will note that all of the vehicles had huge protective bumpers due to the inherent conflict. I doubt Americans will stand for having to share the highway with herds of wild animals.
Thank you for your article on a Livestock-free America. You raised some important issues, such as pet food. We Americans do love our dogs and cats! I do wish to correct a scientific error, however — calcium and other nutrients can ALL be obtained through several vegetables, including brocolli and spinach — the ONLY nutrient that meat and dairy provide that plants can’t is vitamin B-12, and any good vegan will attest to the need for supplemental B-12 in their diet. Just sayin’. 🙂
From my read of the article, the authors agreed with you about the value of plants for nutrients. As I remember it, their conclusion was that it would be very difficult to grow enough to provide adequate nutrition to everyone. You might check the article and see what you think. I could have misunderstood.
There is a difference between plant forms and animal forms of most vitamins, fats, and nutrients. We are terrible converters of plant-to-animal forms, such as the super important omega-3 DHA (from ALA, the plant form, we humans max out at 5% conversion). We also need fat in our diet to help us absorb the fat-soluble vitamins, like A, D, and K, which in animals comes as a package (liver, milk, etc) but in plants needs to be combined. Unfortunately vegans miss this, and slowly erode their health away. We are hunter-gatherers, and any variance from this keeps us from health.