This article is part of a special report on Red Meat. To see the other articles in this series, click here.
After reading my recent articles about red meat, I hope none of you are concerned that eating it will negatively impact your health. But I realize that nutrition is only one of the factors that motivate people to limit or eliminate red meat consumption; one of the primary reasons many go vegetarian is their concern about environmental impact.
We’ve all heard the claims that red meat production is harmful to the environment, so in this two-part series, I’d like to address some of those concerns. In many ways, the environment is as complex as the human body, so measuring the impact of meat production isn’t clear-cut. But at the very least, I hope to shed some light on the topic, dispel some common myths, and put the issue in perspective.
A commonly cited statistic is that cows produce more greenhouse gases than all the world’s transportation combined, or 18% of all greenhouse gases. This statistic originated from a report by the UN Food and Agriculture Association called Livestock’s Long Shadow, and has since been cited frequently in the media and elsewhere as a reason to stop eating red meat. If you think that figure sounds unbelievable, you’re right; it turns out that the researchers were quite biased in their calculations, resulting in numbers that were skewed. One of the authors of the report even admitted later that it wasn’t a fair comparison. A more accurate analysis of the data resulted in a much more respectable estimate: that cattle contribute less than 3% of global greenhouse gas emissions. (1)
However, even the revised figure doesn’t take into account that grazing livestock can actually help remove carbon from the atmosphere. (2) Grasslands are capable of sequestering more carbon than any other ecosystem, and livestock can enhance the incorporation of carbon into the plants and soil. (3) One study showed that grazing cattle can also reduce the land’s natural emissions of nitrous oxide, a greenhouse gas that environmentalists agree is more damaging than carbon dioxide. (4) Some research shows that when cattle are raised on natural pasture with no additional fertilizer or supplemental feed, their ability to enhance carbon sequestration actually outweighs their greenhouse gas emissions. In other words, under the right circumstances, cows are carbon negative!
Another common argument against red meat production is that it supposedly uses way more than its fair share of water. Graphics like this are often used to display how water-intensive red meat is compared with other foods. But are these figures accurate? Consider that previous studies have come up with water usage figures anywhere from 209 L/kg of beef to 105,400 L/kg of beef. (5) That’s a huge difference! When there’s that much variation, it usually pays to look a little deeper into the research to see what’s going on.
One reason for this variation is simply location. Water usage is going to be very different, say, for a feedlot in the US than for a pastoralist in Australia. But another reason is that researchers don’t always agree on how to classify ‘water use,’ and this creates some serious methodological inconsistencies in the literature.
Feed production is the most water-intensive part of raising livestock for red meat, whether the feed is grain, soy, or forage-based. (6) Some of this water comes from natural rainfall, while some is supplied through various irrigation methods. The problem is that many researchers don’t distinguish between rainfall and other forms of water use. This means that a large portion of the water attributed to red meat production is simply rain that falls on the fields or pasture used to feed the livestock.
Although measuring in this way does give an accurate depiction of the sheer amount of water that’s necessary to produce red meat, it gives little to no indication of how environmentally friendly red meat production is. It doesn’t make sense to say that raising cows on non-irrigated pasture drains water resources, when the only water being used is natural rainfall. Even feed crops often receive much of their water through rainfall, and it just isn’t logical to classify that in the same way as, say, drawing water from a nearby reservoir for irrigation.
Luckily, some researchers from Australia thought the same thing, so they did their own analysis. (7) They measured the actual water usage of three different production systems in southern Australia over the course of two years. They classified ‘water use’ as water that was “removed from the course it would take in the absence of production or degraded in quality by the production system.” Thus, under their calculations, things like rainfall and evaporation weren’t counted towards the total ‘water footprint’ of beef unless the water quality was somehow reduced when it reentered the water cycle. To me, this approach gives a much more accurate picture of the impact red meat production has on water resources.
The researchers analyzed a small organic beef supplier, a larger supplier where the animals spend part of their time in a feedlot, and a mid-sized sheep meat supplier. For the systems without a feedlot, they came up with a range of 18-214 L/kg of meat, depending on the year and whether they were measuring water use based on input amount or output quality. For the feedlot system, they came up with a range of 34-540 L/kg. Compared to earlier estimates of 15,000 L/kg and beyond, these new estimates are tiny! However, these results can only be generalized to southern Australian production systems, and systems in the US tend to be more irrigation-intensive.
For a US-specific estimate, we can look at an older study on the average water required for beef production in the US. (8) This study was based on national government statistics as opposed to actual water usage measurements from individual production systems, but they classified ‘water use’ in a similar manner to the previous study by excluding rain and only counting the water needed for irrigation, drinking, and processing. They came up with 3,682 L/kg of meat, which is significantly higher than the Australian estimate. This reflects the higher use of concentrate-based feeding in the US, which usually requires more irrigation than natural pasture. However, this estimate is still much lower than some of the most commonly cited numbers, and demonstrates that red meat isn’t singlehandedly draining the world’s freshwater resources.
In the second article of this two-part series, I’ll discuss the claim that grazing livestock leads to soil erosion and desertification, as well as the different environmental impacts of grass-fed versus grain-fed meat.
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