For most of the past decade, meat consumption in the United States was falling. In 2014, Americans ate 18 percent less beef, 10 percent less pork, and 1.4 percent less chicken than they did in 2005, according to the US Department of Agriculture.

For environmental, health, and animal welfare advocates, this was great news. Surely it meant that efforts to raise awareness about the disturbing impacts of meat production were inspiring people to cut back on hamburgers and bacon. As Paul Shapiro, vice president of Farm Animal Protection for the Humane Society of the United States, wrote in 2012, "The pressure is being felt all over, and for the first time in decades, our overconsumption of meat is beginning to get reined in."

Now it appears that might have been a bit too optimistic. The American way of gorging on meat, it seems, isn’t budging anytime soon.

According to a recent analysis from Rabobank, a Dutch bank, consumption of meat in the United States rose by 5 percent in 2015 — the biggest increase in 40 years. And, the author notes, in the coming years per-person meat eating is expected to reach highs not seen in more than a decade .

"There’s a roller-coaster effect here, and we are about to start an upswing," says Will Sawyer, an animal protein analyst with Rabobank and the author of the report.

That means Americans will remain among the biggest meat eaters on Earth. And it’s clearer than ever that meat consumption is a really tough behavior to change.

Activists who desperately want us to cut back may need to think harder about what messages American consumers really respond to. They may need to reach new people who can't fathom how a plant-based diet could possibly be delicious. And perhaps it’s time to think about other ways to blunt the harms of meat production and consumption.

How US meat consumption bounced back after years of decline

As it turns out, there was a simple reason meat consumption dropped between 2005 and 2014. It wasn’t growing awareness about animal rights or the environment; instead, it was that supplies were tight and prices were higher.

Ranchers and farmers trimmed their herds because of the recession, historically high feed costs, and drought in the Great Plains. Meanwhile, domestic disease outbreaks like porcine epidemic diarrhea virus, or PEDv, meant that tens of thousands of hogs never made it to market. So Americans cut back on meat.

But by 2015, many of these issues driving higher prices were resolved. The retail price of beef has dropped by 22 percent, pork by 7 percent, and chicken by 5 percent. So Americans are eating more meat again.

"Consumers are responding to falling prices. That’s a big part of the story," says Sawyer. The chicken industry, in particular, has also gotten more efficient and more capable of raising chickens fast. (In some cases, there’s been oversupply and a rise in cold storage of meat.)

As a result, Sawyer expects that by 2018 we’ll find ourselves back at the per capita meat-eating levels of the mid-2000s. "All those US consumers that got priced out of the beef market are going to be able to come back to price level that they haven’t seen for five to six years," he says.

Still, a lot of influential people are worried about meat’s impact on the planet

While meat producers and meat lovers may cheer the "record US protein expansion" described in the Rabobank report, it also may represent the failure, so far, of the effort to convince Americans to eat less meat.

We now know that the de facto industrial model of raising livestock has had all kinds of negative impacts: It’s a major contributor to climate change, antibiotic resistance, water pollution, and air pollution. The people who raise and kill the animals often work in unjust, unhealthy conditions. Feeding the billions of animals we raise for meat with corn and soy takes up precious land and puts pressure on wildlife. And we have good evidence that high meat consumption is linked to risks of cardiovascular disease, diabetes, some forms of cancer, and premature death.

There’s a whole cottage industry of people raising concerns about the meat industry, from activists to nonprofits to scientists to international policy wonks at places like the Chatham House and the United Nations. We have piles of popular books (In Defense of Food, Eating Animals, The Meat Racket) and documentaries (Forks Over Knives, Food Inc.) on these topics, and we’ve seen everyone from Venus Williams to Bill Gates to Jim Cameron to Pastor Rick Warren decry the American way of producing and eating meat.

As author and neuroscientist Sam Harris noted on a recent podcast, he and Yale psychologist Paul Bloom think eating meat raised the conventional way will be something our descendants will be as scandalized by as we are about slavery: "We’ve both said our descendants would be horrified to know what we did with factory farming — the way we mistreated and killed billions of animals in a way we managed to do more or less with a clear conscience simply because we were keeping the details out of sight and out of mind."

Yet for all the pronouncements, reports, and "Meatless Monday" events urging us to eat less meat, it’s clear the needle hasn’t moved very much. (In fairness, it’s impossible to know what consumption would be without those awareness campaigns, as Paul Shapiro of the Humane Society of the US points out.)

Indeed, Blake Hurst, a Missouri farmer and longtime critic of the food movement, had a point when he wrote this month in National Review, "We now all talk like [Michael] Pollan, but, a decade on, we still like a good hamburger or a perfectly prepared steak."

Vegetarianism is growing, but it remains relatively small

What makes this result so surprising is that it often seems like vegetarianism is on the rise.

It's increasingly touted in popular media as a way to reduce greenhouse gas emissions and improve health. We’re seeing more and more veggie burgers and other meat alternatives on grocery store shelves and menus. A renowned Stanford geneticist invented a version of one with genuinely "meaty umami" flavor (listen to Vox’s Ezra Klein’s interview with him for more on that). Chef David Chang is now serving that very veggie burger in New York City.

So how do we square these two trends?

Jayson Lusk is an agricultural economist who runs a monthly survey of Americans’ food preferences. He says that overall, he hasn’t seen significant changes over time in terms of consumer preference for meat.

But in the past three years, Lusk has asked people if they were vegetarian or vegan. And here he has found a subtle but clear increase:

"There are two things going on at same time," Lusk says. "The average meat demand has stayed relatively steady. But also on one end of the distribution, there does seem to be uptick in consumers choosing to be vegetarian and vegan."

To him, it’s a sign that a few people are hearing the messages about climate change, health, and animal welfare and are changing their behavior. And there’s other evidence out there that Americans do aspire to eat less meat, like this survey NPR did with Truven Health Analytics.

But it’s hard to tell whether we can expect a bigger shift away from meat anytime soon.

"We know from other research that stories about climate change and animal welfare could have an impact on meat demand. We have a lot of good evidence that news stories on saturated fat had a big impact on demand for beef, eggs, and pork," says Lusk. "But it takes a long time for this kind of change to occur in a big way. It’s hard to predict when a trend will take off and have big impact on meat demand. "

Why is it so hard to convince Americans to eat less meat?

It’s worth looking at why shifting a nation like America away from a food like meat is such a tall order.

Let’s start with the obvious: Human beings enjoy eating meat for powerful biological reasons. It’s flavorful, nourishing, and satiating. It was essential to our evolution.

Biological anthropologist Richard Wrangham argues in his book Catching Fire that the invention of cooked meat made it possible for us to develop bigger, smarter brains. "The extra energy [in the cooked meat] gave the first cooks biological advantages," he writes. "They survived and reproduced better than before. Their genes spread. … There were changes in anatomy, physiology, ecology, life history, psychology, and society."

Meat is also deeply embedded into American food culture: Think of all the holidays, all the iconic meat brands like McDonald’s, all the traditions that revolve around eating meat. We are inundated with marketing and advertisements encouraging us to go for that carnitas burrito and the double bacon cheeseburger.

As food historian Rachel Laudan has argued, eating meat is the expression of being modern, progressive, and civilized: "Here’s the challenge of meat for those who want to persuade people to eat less. ... For many in the United States and for many, many more around the world, meat eating is not just matter of taste or the environment, it’s a foothold, it’s a stake in the rich, modern world. It’s a sign that they too can leave behind the hierarchical societies of the past and be full citizens and enjoy what we already enjoy in the United States."

It’s tough to convince people to cut back on something they crave, something so symbolic that’s largely very affordable and accessible (at least in the United States). Think about how long it took to persuade tens of millions of Americans to quit smoking.

And many have argued that you’re going to need a really compelling alternative to meat to win the battle. According to Sawyer of Rabobank, we’re not there yet. "Plant-based substitutes for meat have not gotten to the point where they can compete with meat on flavor, price, texture," Sawyer tells me. (We are seeing a more significant shift in the dairy sector, where almond and other plant-based milks and cheese have a rapidly growing market share.)

The Impossible Foods veggie burger that bleeds may turn out to be a revolutionary invention. So could some of the other synthetic and lab-grown meat products in the pipeline from the likes of Memphis Meats, Modern Meadows, or Mosa Meat. The group New Harvest is very optimistic about the future of "cellular agriculture." (Read New Harvest CEO Isha Datar’s vision for the "post-animal bioeconomy" here.) But these new technologies and products won’t be game changers unless a critical mass of people buy them and endorse them as palatable alternatives to meat.

Sawyer of Rabobank agrees that the plant-based trend has staying power and could take off; he notes that once people get turned on to and can access lots of vegetables (which many Americans still cannot), it’s easier to eat less meat. Yet "there are hundreds of millions of Americans who don’t really know about plant-based diets or haven’t been persuaded to follow one," he says. It also may seem more expensive (though that’s debatable, since beans are one of the cheapest high-protein substitutes for meat you can buy).

As Sawyer points out, we increasingly live in a tiered food system, where the wealthy can buy alternative products — meatless ones, but also organic and antibiotic-free meats. But those aren't universal. And most people still choose what meat to eat based on what’s the cheapest cut available at Walmart or the latest promotion at Burger King.

If we’re so sensitive to price, should we tax meat?

Americans ate less meat in the past decade because prices went up. So what if we added the costs of greenhouse gas emissions from livestock to the price of meat on a per-pound basis? After all, there’s good evidence that the single greatest contributor to the decline in smoking here was taxing tobacco.

A tax on meat is something Jayson Lusk has thought about quite a bit. Here’s what he writes in a recent blog post:

Suppose you wanted to "internalize" the impacts you're having on climate change by altering how much beef, pork, and poultry you buy. To do this, take the price you see at the grocery store and add about $0.18/lb to the price of beef, $0.04/lb to the price of pork, and less than a penny to the price of poultry, and act as if these were the prices actually being charged. Would you change your behavior much based on such price increase? ... The key isn't to have zero greenhouse gas impacts, but rather to make sure you're taking into account the cost of those impacts.

This is politically unfeasible in the short term — Americans are averse to more taxes, and the meat industry would likely fight any meat tax tooth and nail. Don’t forget that it successfully lobbied to dilute the most recent version of the dietary guidelines after a scientific panel recommended that the guidelines discourage red meat consumption for health and environmental reasons (they no longer do).

If a tax on meat sounds like it would be unfair to the poor, scholars are working on that very question: Check out this paper by researchers writing in the European Review of Agricultural Economics about how a meat tax could "address differing nutrient needs and purchasing behaviors among households."

Another possibility is that activists could focus more on changing production methods.

"It’s really hard to change consumer preferences, since a lot of people like to eat meat," says Lusk. "What can we do with technology and science to reduce environmental and animal welfare impacts of meat production?"

There’s a lot meat producers can do, and they’re already doing some of it. The carbon footprint of beef production fell 16 percent from 1977 to 2007, with much of that reduction resulting from responsible use of technologies. There’s a Global Roundtable for Sustainable Beef, with members like McDonald’s, that’s working to define and measure "sustainable beef."

The beef, pork, and poultry industries are all working to turn some of their waste into energy, use less water, and use fewer antibiotics. There’s a new push for research into breeding and genetic engineering animals that make the same amount of meat but need less food and water.

But as many advocates have pointed out, it’s not nearly enough. Big Meat could make a lot more progress in all of these areas and others. And it's increasingly important to reduce impacts since many countries in the developing world intend to dramatically increase their meat production in the coming years to meet rising demand.

We should also try to keep moving toward a more plant-centric diet. As Lusk notes, it’s possible that it’s simply too early to say the campaigns to reduce meat consumption have failed. One day, the majority of Americans could be turning down burgers and bacon for reasons other than price.

Further reading:

The Johns Hopkins Center for a Livable Future put out a detailed report in December 2015 on how reducing animal protein consumption could help mitigate the effects of climate change.

Vox’s Brad Plumer described how we could grow enough food for everyone on Earth without destroying the planet.

Over at the Conversation, two British researchers make the case for eating pulses to save the world.

Undercover videos help explain meat in America