Ever felt like you wanted to do something for the environment, but wasn’t really sure what? Well, researchers have the solution: eat less meat and dairy.

It might not seem like the most straightforward thing, but a new study has found that livestock provides only 18% of all the calories we consume, but takes up 83% of all farmland.

Without meat or dairy consumption, global farmland use could be reduced by more than 75%, freeing up an area larger than all of the US, China, European Union and Australia combined. It would free up countless ecosystems, drastically reduce environmental pressure, and reduce much of our greenhouse gas emissions.

“A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use,” said Joseph Poore, at the University of Oxford, UK, in a press release. “It is far bigger than cutting down on your flights or buying an electric car,” he said, as these only cut greenhouse gas emissions.

The study assessed the full impact of these foods, from farm to fork, on land use, climate change emissions, freshwater use, water pollution (eutrophication) and air pollution (acidification).

“Agriculture is a sector that spans all the multitude of environmental problems,” Poore continues. “Really it is animal products that are responsible for so much of this. Avoiding consumption of animal products delivers far better environmental benefits than trying to purchase sustainable meat and dairy.”

Of course, that’s not realistic — we can’t expect all meat and dairy consumption to disappear overnight, but even so, we could reduce it. Every pound of meat we reduce from our diet has an important effect on the environment. For instance, every pound of beef requires about 8000 liters of water, whereas an equivalent quantity of potatoes consumes over a thousand times less water. Even eggs only need about of fifth of what beef needs. The figures for land use are similar.

Okay, you might say, but potatoes don’t provide the same nutrients as beef, do they? Well, the new study found that the plant-based replacements of meat, which offer similar nutrients, also have a dramatically lower environmental impact.

“Avoiding consumption of animal products delivers far better environmental benefits than trying to purchase sustainable meat and dairy,” Poore added.

It’s not even about reducing all the meat. The study found that if only the most harmful half of meat and dairy production was replaced by plant-based foods, that would reduce more than 66% of the impact of the entire industry.

The study also highlighted a few unpleasant surprises. For instance, freshwater fish farming, long thought to be an environmentally-friendly practice, was responsible for a surprising amount of emissions. This is largely due to the methane produced by the unconsumed fish feed and excreted material, which deposit at the bottom of the lake. Grass-fed beef, thought to be a more sustainable practice, was found to be anything but.

“Converting grass into [meat] is like converting coal to energy. It comes with an immense cost in emissions,” Poore said.

This shouldn’t be taken as a call to turn vegetarian or vegan overnight — not at all. But it is a call to understand the impact our consumption is having on the planet, especially as this isn’t the first study to come to this conclusion. In fact, there’s a mountain of research documenting the negative impact of meat and dairy, and showing that reducing our consumption of animal foods can be impactful on many levels.

Moderating our meat and dairy consumption is not just eco-friendly, it’s also healthy. No amount of processed red meat is good for you, and even low amounts can be dangerous for your health.

The bottom line is simple: want to live a longer, healthier life, and do something amazing for the environment? Eat less meat!

Journal Reference: J. Poore, T. Nemecek. Reducing food’s environmental impacts through producers and consumers. Science. DOI: 10.1126/science.aaq0216

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