Credit: Garry Gay via Getty Images Beef is one of the most resource-intensive foods you could eat. Time to cut back.

We’ve known for some time now that eating meat is putting a massive strain on our planet.

But if you want to take steps to reduce the carbon footprint of your dinner, it’s not necessary to eliminate animal products entirely to have a big impact on diet-related greenhouse gas emissions that contribute to climate change.

According to a new working paper released Wednesday by the World Resources Institute, a D.C.-based nonprofit research organization, simply cutting back on meat and dairy would help the average American cut the environmental impact of what they eat almost in half.

The paper calculated the environmental impacts of several different dietary scenarios and found that if countries currently over-consuming meat cut back their average consumption to 60 grams a day — about half what Americans currently eat — the result would be a drop of 40 to 45 percent in agriculture-related greenhouse gas emissions.

Janet Ranganathan, the paper’s lead author and vice president for science and research at WRI, said those numbers show that a vegetarian or vegan diet is not required to increase the sustainability of the world’s food supply.

“Small changes, small shifts and reductions can make for a meaningful reduction in your carbon footprint,” Ranganathan said. “It’s easy to make shifts here and there and make a big difference. You don’t have to go all out.”

A somewhat less ambitious strategy focused solely on beef, which uses dramatically more land and water than other animal proteins, could also prove effective.

If the world cut its beef intake by 30 percent, agriculture-related greenhouse gas emissions would drop 35 percent. This could be achieved by countries that currently over-consume beef ― such as Canada, the U.S. and Brazil, among others ― reducing their intake to the world average of 3.2 grams of protein from beef a day.

Similarly, if regions that over-consume beef cut their intake by 33 percent and replaced the beef either with other animal proteins like pork and poultry or with legumes, emissions would drop about 15 percent.

The reason these diet changes would have such a dramatic effect is because we’re eating so much meat to begin with.

Per-capita meat consumption has been rising internationally since 1961. While the United States and Europe continue to lead the way, emerging economies like Brazil, China and Indonesia have seen growing demand that is projected to continue in the decades ahead.

At the same time, the WRI analysis notes, Western-style diets that are high in animal-based foods, as well as refined carbohydrates, sugars and fats, are becoming more of the global standard as incomes rise, urbanization increases and technology improves.

This is all bad news for the environment.

Animal-based foods are responsible for about two-thirds of the agriculture sector’s production-related greenhouse gas emissions globally, but only contribute about 37 percent of the protein consumed. All told, the agriculture sector is said to be responsible for 18 percent of the world’s emissions of gases like carbon dioxide, nitrous oxide and methane, according to the United Nations Food and Agriculture Organization.

In the U.S. alone, animal-based foods account for almost 85 percent of those emissions.

This is also bad news for our ability to feed a growing world population.

Based on the FAO’s projections, the world will face a 70 percent “food gap” between the amount of crops available to consume in 2006 and the global food demand projected by the year 2050.

Because increases in agricultural yields can only do so much to fill that gap, conserving resources and decreasing consumption of resource-intensive foods, like meat, appears increasingly necessary.

Americans, it turns out, have a lot of room to cut back.

The average American currently eats almost double the average daily protein requirement of 50 grams, and consumes less plant-based protein than people in any other region considered in the study.

The degree of protein overconsumption came as a surprise to Ranganathan. She told HuffPost the trend flies in the face of typical defenses of meat-heavy diets — that we are otherwise at risk of running a protein deficit.

“I don’t think people appreciate that they are getting as much protein as they are,” Ranganathan said. “There’s an anxiety about cutting meat back that people won’t get enough protein. But, by and large, most people don’t need to worry about that.”

So can it work? Ranganathan sees room for optimism.

Along with the paper, the WRI released a scorecard that helps consumers evaluate the environmental impact of the proteins they eat. One of the biggest culprits on that scorecard has already taken a hit: U.S. beef consumption, which peaked in the 1970s, has already been on the decline for decades.

But more work is needed, and some of the efforts to cut meat intake -- educational campaigns and "Meatless Mondays" -- have had a limited impact.

“The strategies we’re using today are not proving effective,” Ranganathan said. “They might be with a small group of people, but not with the billions of people who need to shift their diets. But we think we have a fighting chance here.”

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Joseph Erbentraut covers promising innovations and challenges in the areas of food and water. In addition, Erbentraut explores the evolving ways Americans are identifying and defining themselves. Follow Erbentraut on Twitter at @robojojo. Tips? Email joseph.erbentraut@huffingtonpost.com.