Beef's Impact on Climate

Eating Less Meat Won't Save the Planet. Here's Why

Can you sketch the argument here? I'm happy to make a counterargument, but I don't have 15 minutes to spend watching something that may be boring.

In broad strokes, my position is that meat eating--particularly beef, to a lesser extent others--uses more carbon than a plant-based diet. One coarse piece of evidence for this is that vegetarian diets cost less than beef-based diets today, indicating less energy intensity and fewer hours of human labor going into it.


There is a popular argument that meat, beef in particular, has a large negative impact on climate due to the amount of water, food, land, and GHG emissions required to produce it. All four prongs are misleading and meat from ruminants (ex: cows, sheep) isn't obviously worse than other food sources and is compatible with environmentally friendly agriculture.

On water, it's common to see arguments like "this hamburger required >1000 gallons of water to produce", but what's not stated is where that number comes from. The common versions of that statistic come from estimating how much food the cow ate and then estimating the water needed to produce that food. But, ~95% of that water came in the form of rain or other renewable water sources, which is then recycled into the environment. Only the remaining 5% come from non-renewable fresh water sources like wells, etc., and the absolute amount is comparable to that used to produce other foods: for 1/4 lb of food, beef requires ~120L of water, compared to 90L for rice or 1000L for almonds.

For food, it's argued that it's wasteful to feed cows a lot of food and then only get a small amount of beef rather than eating the food directly. However, >90% of what ruminants eat is inedible to humans, including a lot of agriculture byproducts. Ruminants needs only about 2.8kg of human-edible food to make 1kg of meat (slightly better than non-ruminants which use more human edible food!). Note that this is taking generally high starch foods and converting it into high protein food, which would serve most Westerner's diets well.

On land, it's often quoted that the amount of land devoted to raising cattle is much greater than that devoted to raising food. This is true, but ignores that not all agricultural land is equally valuable. Since ruminants can eat food inedible to humans, they can use marginal land (rocky, hilly, poor soil, etc.) that can support some vegetation but can't be productively used for human crops.

Most important in my mind is the issue of GHG emissions, where meat is blamed for a significant share of emissions in the form of methane, which of course creates an even more potent greenhouse effect than CO2. However, there are two large problems in the popular anti-meat arguments. First, most of the highly publicized cow GHG emission numbers are gross emissions not net emissions. For fossil fuels gross and net are essentially the same. But beef, like all agriculture, is more like a biofuel: the methane emitted by cows comes from carbon in the vegetation they eat which comes from atmospheric CO2. So the net GHG emissions are much lower and mostly involve the external energy inputs into the system. [It didn't give a number how much lower and I consider this the video's biggest omission. It mentions a little later that all livestock emissions account for 2-4% of global emissions but I'm not sure if that is based on gross or net emissions. My guess would be gross, so this is an upperbound.]

Second, methane breaks down in the atmosphere after about 10 years, compared to 300-1000 for CO2. So, if your cattle numbers are constant over at least 10 years, as they have been in the US, then it's not making additional GHG emissions on net since the system is at equilibrium. Conversely, CO2 levels will continue to rise for hundreds of years even if emissions stopped growing.

The video also spends some time discussing that the averaged percent of emissions due to livestock isn't a very meaningful number, but I don't really think this is an important point. However, it was interesting to point out that the efficiency, in terms of product per cow, can vary by an order of magnitude, suggesting there are lots of gains to be made.

Finally, it concludes that we shouldn't let meat distract from the most important sources of GHG, fossil fuels and concrete, especially since meat eating quickly becomes politically divisive. It also notes that if you do want to focus on a food related aspect of carbon emissions, you would be much better served by looking at food waste since it is a substantial fraction of food related emissions, and has nothing in its favor like meat does.