Cows and climate change

By now you’ve probably heard rumours about cow farts containing greenhouse gases or that reducing the meat in your diet will save the planet. But how true are the things you’re hearing? Today, I’d like to go through and fact check some rumours and claims to see where the truth is.

First of all, I’d like to establish what climate and climate change is. Climate is not weather. Weather is how cold or warm or rainy or sunny it is on one particular day. Climate is the pattern. It’s how consistently it is warm or cold or rainy or sunny during certain times of the year. We are experiencing climate change. Things like warmer Arctic temperatures delivering an Arctic blast as far south as the Midwest and more frequent severe storms during the summer months attest to this.

In agriculture, climate change is especially concerning, because agriculture is dependent on Mother Nature cooperating. We have benefited greatly from advanced crop breeding and management techniques that help keep our corn and soybeans healthy during drought or mild flooding, but if there are multiple feet of water standing in a field when the crop is ready to harvest, no amount of genetic superiority can get a combine out and save that crop from spoiling.

“Rising temperatures, extreme heat, drought, wildfire on rangelands, and heavy downpours are expected to increasingly disrupt agricultural productivity in the United States. Expect increases in challenges to livestock health, declines in crop yields and quality, and changes in extreme events in the United States and abroad threaten rural livelihoods, sustainable food security, and price stability.”

– National Climate Assessment, Fourth National Climate Assessment, Volume II

Because we know climate change to be a real threat to agriculture and rural communities, it’s important that we take steps to understand and mitigate its risk. At least one piece of that is hearing arguments and deciphering what is true and what is distracting us from solving the issue.

Cow farts are causing climate change

I personally started hearing about this idea about 12 years ago. At the time, I thought it was a joke (I mean, I was 12). But now, it’s being taken much more seriously. What is going on with cow farts, and do they really impact our atmosphere?

Cattle, like people and all other animals, do fart and burp. It’s just a thing that happens in a healthy digestive system. When you hear people talk about “cow farts” in conjunction with climate change, they’re really getting at methane (CH₄). The kicker is, cows don’t actually fart methane; they mostly burp it.

Yes, cattle do burp (or eructate, in scientific terms) methane. Methane is a greenhouse gas, so naturally, this has been a concern in the climate change conversation.

There are a couple key pieces to this conversation to remember. First, though methane has a higher atmospheric warming potential than carbon dioxide (CO₂), it breaks down much faster. Like, 16 times faster.

Secondly, we have to think about where those gases are coming from. A big part of CO₂ being added to the atmosphere comes from burning coal and oil. This is bad, because that carbon used to be stored underground, and we took it out and released it into the atmosphere. This increases the net CO₂ in the atmosphere.

With cattle, the net carbon doesn’t necessarily increase because of where the carbon comes from. Grasses use atmospheric CO₂ to grow, cattle eat the grasses, and they burp methane, the methane breaks back down to CO₂, which feeds the grass, which feeds the cow, and so on.

For an illustration on this cycle and how it compares to other forms of greenhouse gases, check out this video from New Zealand.

Land used to grow food for livestock should be used for human food

This is a common argument, and on some level it makes sense. It seems almost like cutting out the middle man. Why not just eat the food you grow for livestock instead of wasting the time and energy to feed the animals? Well, mostly because crops aren’t that interchangeable.

Take Iowa for example. We are phenomenal at growing field corn (different from the sweet corn we eat) and soybeans. These crops are key ingredients in many livestock feeds. Therefore, we raise lots of pigs and chickens in the state, which become pork and eggs.

It is sometimes argued that these crops are grown because of a need to feed the livestock, but it’s actually that we raise the livestock because we are easily able to grow what they need. The argument that we should eat the crops instead doesn’t take into account that all crops and all environments aren’t created equally. We cannot use field corn the way cattle can, and lettuce can’t use Iowa land like field corn can. Though it may seem cleaner and simpler to compare all calories as equal, it, unfortunately, doesn’t end up working like that.

More plant-based diets will save the planet

OK, so, cow burps are part of a cycle, and cattle feed depends on the types of feed grown in an area, but should we still think about changing our diets? Will that help?

One argument is that in order to raise more cattle, we will need to cut down more forests to increase grazing land, reducing the amount of trees that are currently helping reduce atmospheric carbon. If this were the whole story, you bet, that would be a huge issue.

This argument, much like the previous statement, has kind of been flipped backwards. In reality, cattle raised on pastures, grasslands, and rangelands, are often raised there because that’s the only way to gain value from that land. We don’t create pastures to raise cattle as much as we raise cattle because we have pastures.

For example, in northern Iowa (on the Des Moines lobe, if you know your geographical features), you find miles and miles of flat land growing acres and acres of row crops. You don’t see a lot of cattle grazing here, because the land lends itself better to using tractors and implements and growing high quality crops. In southern Iowa (on the Southern Iowa Drift Plain), you see steep hills, more forested areas, and lots more pastures. These steep hills are at much greater risk of erosion if they were to be worked under to grow annual row crops. We can still get food from this land, however, because of ruminant animals like cattle. This idea is called upcycling.

The big picture in any major issue is often messy. We innately try to clean it up by quantifying qualitative things or comparing apples to oranges, but that doesn’t actually help solve our problems.

Admittedly, cow burps do contain methane and that methane is contributing to the overall levels of methane and other greenhouse gases in the atmosphere. To curb climate change, we all need to pay attention to this and what we can do to reduce greenhouse gases. But, we can still stand by data stating only 2% of emissions are coming from cattle production, and other agriculture is contributing up to 6% of methane emissions. This is a small piece of the puzzle. While agriculture will work to address these issues, a much larger impact could be made by addressing carbon dioxide emissions from fossil fuels and industrial processes (accounting for up to 65% of global greenhouse gas emissions, according to the EPA). Most of our emissions are coming from using non-renewable resources, like coal and oil.

At least for me, that’s good enough to keep eating burgers.