A new online calculator has shown the shocking impact of meat-heavy Western diets - and what would happen if everyone ate the diet of people in the US.
If everyone on the planet consumed an American diet, some 138% of the planet’s surface would be needed to produce the food, scientists found.
Researchers at the Omni Calculator Project checked over 1,500 studies and consolidated data from over 38,000 farms in almost 130 countries. You can calculate your own environmental impact using the Omni Calculator tool.
In the last 50 years, the amount of meat eaten globally has quadrupled, exceeding 320 million tonnes per year, the researchers said.
PhD student Hanna Pamula created the calculator by looking at how meat consumption impacts land use, water and air pollution, and the carbon dioxide equivalent.
Eating just one serving of chicken, pork, beef, lamb or fish a week can have a devastating impact on your carbon footprint, the researchers said.
Five servings of meat a week wastes 14,363 litres of water, the amount of water 13 people drink in a year.
Thirty-one trees are needed to absorb the CO2 emissions over a month and the amount of energy used is equivalent to 7,320 smartphones charged, 24.4 litres of petrol used or 228 kilometres travelled in an average passenger vehicle.
The Omni Calculator Project, based in Poland, is a small team of doctors, scientists, economists and PhD students building online tools.
Ms Pamula said: "I'm not trying to convince everyone to go vegan. Even a small reduction in meat consumption can make a noticeable difference.
"We don't need a handful of people performing meat reduction perfectly, by changing to a vegan or vegetarian diet.
"We need millions of people doing it imperfectly, reducing meat consumption as much as possible."
She added: "Animal agriculture is the second largest source of human-caused greenhouse gas emissions.
"Meat consumption has recently soared, as more countries begin to develop and global society is getting richer.
"Unfortunately, meat is a very inefficient food if you take into account the resources needed for production and the amount of protein obtained."
Ms Pamula said: "Beef production needs the most water - it requires over 4,000 gallons of water to produce 2.2lbs (1kg) of meat, making it the most water-intensive protein.
"That's rather a lot, especially when compared to what we drink on a daily basis."
Ms Pamula also noted that meat takes up far more land than growing vegetables, with beef production requiring 22 times more land than pea production.
She said: "Differences in dietary habits are immense - if every person in the world had the UK's meat consumption and average diet, 95% of global habitable area would be needed for agriculture.
"Even more terrifying results appear if the whole world chose the US average diet - 138% of the global habitable area would be needed.
"Unfortunately, we can't do it - we don't have a spare planet.