[This article was first published in 2018]

Eating a vegan diet could be the “single biggest way” to reduce your environmental impact on earth, a new study suggests.

Researchers at the University of Oxford found that cutting meat and dairy products from your diet could reduce an individual's carbon footprint from food by up to 73 per cent.

If everyone stopped eating these foods, they found that global farmland use could be reduced by 75 per cent, an area equivalent to the size of the US, China, Australia and the EU combined.

Not only would this result in a significant drop in greenhouse gas emissions, it would also free up wild land lost to agriculture, one of the primary causes for mass wildlife extinction.

The new study, published in the journal Science, is one of the most comprehensive analyses to date, looking into the detrimental effects farming can have on the environment and included data on nearly 40,000 farms in 119 countries.

The findings reveal that meat and dairy production is responsible for 60 per cent of agriculture’s greenhouse gas emissions, while the products themselves providing just 18 per cent of calories and 37 per cent of protein levels around the world.

Researchers examined a total of 40 agricultural products in the study, covering 90 per cent of all food that is eaten.

They looked at how each of these impacted the environment by analysing climate change emissions, water pollution and air pollution.

Lead author Joseph Poore said: “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."

“It is far bigger than cutting down on your flights or buying an electric car,” he explained, which would only reduce greenhouse gas emissions.

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

The research also looked into the different techniques used to produce the same foods and found vast distinctions in terms of environmental impacts.

For example, beef cattle reared on natural pastures used 50 times less land than those raised on deforested land.

The latter can leads to up to 12 times more greenhouse gas emissions by comparison.

This starkly contrasts with emissions of greenhouse gases released as a result of plant-based protein production for items such as tofu and peas.

Poore also explained that even production methods which are thought of as sustainable, such as freshwater fish farming and grass-fed beef, can pose environmental problems.

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

Poore’s research is the result of a five-year-long project, which initially began as an investigation into sustainable meat and dairy production.

He stopped eating animal products altogether himself after the first year.

The next step, Poore told The Independent, is to find ways to test his proposed approach in practice.

"The problem is, you can’t just put environmental labels on a handful of foods and look to see if there is some effect on purchasing," he said.