Is veganism the environmental answer? Study finds plant-based diet produces 75% less greenhouse gases than high-meat

A new study of tens of thousands of Brits has found completely plant-based diets produce just a quarter of the greenhouse gases of high-meat diets - and could go a long way towards reducing individual environmental impact in other ways too.

The University of Oxford research - published in Nature Food on Thursday (20 July) - looked at the eating habits of 55,000 people in the UK. It found meat-free eating had a substantially lower environmental impact, across metrics including land use, water pollution risk, water use and biodiversity loss.

While past research has shown that plant-based diets generally produce fewer greenhouse gases, use less water and are healthier for the body, the Oxford University team said they may not have taken into account how and where that food is produced.

Lead author Professor Peter Scarborough said the researchers asked 55,000 people in the UK to fill out a questionnaire, categorising them into vegans, vegetarians, pescatarians, high and low-meat eaters.

His team then connected the information with databases estimating the environmental impact of various food to include in the final analysis.

“Cherry-picking data on high-impact, plant-based food or low-impact meat can obscure the clear relationship between animal-based foods and the environment," Professor Scarborough said.

“Our results, which use data from over 38,000 farms in over 100 countries, show that high-meat diets have the biggest impact for many important environmental indicators, including climate change and biodiversity loss."

Cutting down the amount of meat and dairy in your diet could make a big difference to your dietary footprint, he continued. Compared to high-meat diets, vegans were found to have a quarter of the environmental impact from greenhouse gases and land use, 27% of the impacts for water pollution, 46% for water use, and 34% for biodiversity loss.

Even eating less meat made a noteworthy difference, the study found, with low-meat diets at least 30% lower in these categories than high-meat.

The Oxford University team said these results meant policymakers needed take action to reduce meat production and consumption, to support the UK in meeting its environmental goals - such as net zero greenhouse gas emissions by 2050.

In a Commons committee hearing on food security last week, farming minister Mark Spencer said he would prefer to see meat production made more efficient than to tell people what to eat.

He said agriculture is improving its efficiency by 1% a year, and he would like to see genetically-modified cows that emit less methane.

But Caroline Lucas, questioning Spencer, slammed government’s disinclination towards encouraging vegetarianism as “perverse”, and it had “double standards” for raising tax on sugar, tobacco and alcohol, but not meat.

A government spokesperson told PA: “People should make their own decisions around the food they eat.

“Achieving the net zero target is a priority for this Government, and whilst food choices can have an impact on greenhouse gas emissions, well-managed livestock also provide environmental benefits such as supporting biodiversity, protecting the character of the countryside and generating important income for rural communities.”

Agriculture is a major source of deforestation and biodiversity loss, according to the UN. The food system is responsible for 70% of the world’s freshwater use and 78% of freshwater pollution, and is the second-largest producer of greenhouse gases after energy.