A cowboy warms up before a roping event at a rodeo in Wyoming. (Michael Smith)

Each week, In Theory takes on a big idea in the news and explores it from a range of perspectives. This week we’re talking about meat consumption. Need a primer? Catch up here.

Blake Hurst is a farmer in northwest Missouri and president of the Missouri Farm Bureau.

Pity the poor cowboy. Once the hero of hundreds of movies, television shows and pulp novels, he’s no longer an icon. Instead, he’s a social pariah, spending his days caring for cows, the worst environmental villain that modern man can imagine.

No longer a larger-than-life figure like John Wayne or Gary Cooper, the present-day cowboy has the social cachet of an Exxon executive without the stock options or the private jet. He’s still out there on his horse or his four-wheeler, but he’s no longer anyone’s hero.

True, he’s finally free of the diet mavens who bedeviled him for a generation (four meta-analyses published since 2009 have failed to find any connection between consumption of saturated fat and heart disease). But now our lonely cow-puncher is attacked by global climate-change warriors, who have decided that only the hamburger stands between modern man and Eden.

I remember my fall 1975 introduction to the rumen, which is one part of the cow’s four-part stomach. The cow had a viewing port in her side, and college classmates and I had the chance to get a firsthand view (and smell) of what was going on in our beef animal’s stomach. It still strikes me as something of a miracle. Grass, hay, weeds, thistles — all plant material useless to humans — changed by the rumen into porterhouse steaks.

What we smelled that day was methane — the proximate cause of the cowboy’s present malaise, but we didn’t know that then. We just knew that most land isn’t suitable for the production of corn, lettuce, cabbage, kale or arugula — and it isn’t today. Cows make marginal land a source of nutrition, and that’s an amazing thing. The main indictment of the beef industry is that it isn’t sustainable, but surely a large part of sustainability is the cow’s ability to use what we cannot, benefiting us in the most delicious of ways. And yes, I know that cows eat corn — but they typically only do so in the last few weeks before they go to market, while “grass-fed” cattle spend their whole lives eating grass and other roughage.

Yet today we are told as often as a cow regurgitates her cud that the methane from millions of those miraculous rumens is an especially powerful cause of global warming. According to the United Nations Food and Agriculture Organization, livestock accounts for around 15 percent of global greenhouse gas emissions. Is that too much? Not if you are hungry — if you’re in a developing nation where the only easy food source is meat, for instance, do what you must. But as Americans who have plenty to eat, we should certainly ask about the environmental cost of our love affair with steak.

Economist Jayson Lusk has attempted to answer that question by using the Environmental Protection Agency’s estimate of the carbon equivalent of methane emissions released by the production of beef, dividing that total by the pounds of beef we eat and multiplying the result by the EPA’s estimated carbon cost to the environment. When you’ve done all those calculations, you have an estimate of the carbon cost of beef. That number, according to Lusk, is about 18 cents per pound — not an enormous cost in the grand scheme of things. Worried about the environmental impact of eating beef? Just consume what you would if a Quarter Pounder cost an extra four cents.

Before we decide that beef is a luxury that humankind can no longer afford, a little bit of history might be in order — a reminder that the future is hard to see. In 1980, the U.S government published the first set of dietary guidelines, which called for less saturated fat and less red meat. Since then, we’ve cut our consumption of beef by about a third, and the obesity rate in the United States has nearly tripled. Of course, correlation doesn’t mean causation, but we at least should apply skepticism to the latest dietary fad or grand plan to save the world by a single change in our diet.

Cowboys will always be my heroes. And I will always eat steak to celebrate the milestones in my life. Somehow, tofu for a graduation or broccoli for a promotion just doesn’t seem right. Cowboys have learned to produce beef more efficiently, cutting methane emissions significantly in the past 30 years using better feed efficiency and encouraging faster growth. If that trend continues — and there is no reason it shouldn’t — we can celebrate our special occasions without guilt. So, fire up the grill, and enjoy beef. It’s the cowboy way.

Other perspectives:

Brian Kateman: We can save the earth without giving up bacon. Here’s how.

Laura Wellesley: We need to eat less meat. Should the government step in?