This research, leveraging the eating habits of 55,000 individuals, further demonstrates that diets free from meat substantially decrease environmental impact, affecting land use, water use, water pollution risk, and biodiversity loss.
“Cutting down the amount of meat and dairy in your diet can make a big difference to your dietary footprint,” said study lead author Professor Peter Scarborough.
This research adds to a growing body of evidence suggesting that a radical change in our dietary habits could be key for mitigating the accelerating effects of climate change.
Agriculture is a chief contributor to deforestation and biodiversity loss, and has commanded three-quarters of ice-free land for human use, according to UN data.
Additionally, our food system is responsible for a staggering 70% of the world’s freshwater use and 78% of freshwater pollution. As if that wasn’t enough, it also ranks second in producing greenhouse gases, just behind energy production.
A previous study from 2015 found that the direct and indirect greenhouse gas emissions from food production constituted approximately one-third of total emissions for that year.
Although it has been established in earlier research that plant-based diets yield fewer greenhouse gases and demand less water, these studies may not have fully considered the ways and places where food is produced.
This latest study, recently published in the journal Nature Food, involved a survey completed by 55,000 UK participants. Respondents were categorized as vegans, vegetarians, pescatarians, and either high or low meat eaters.
The Oxford research team proceeded to integrate these data with databases that quantify the environmental impact of different food types for a comprehensive analysis.
According to Professor Scarborough, focusing on the data for high-impact, plant-based food or low-impact meat can distract from the salient correlation between animal-based foods and environmental degradation. He emphasized the importance of their comprehensive approach.
“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,” said Professor Scarborough.
The environmental impact of vegans was found to be a mere quarter of that of high-meat diets, in terms of greenhouse gas emissions and land use.
For water pollution, this figure was 27%, 46% for water use, and 34% for biodiversity loss. Even those following a low-meat diet showed considerable improvements, exhibiting at least a 30% reduction across these environmental impact categories.
The research team suggests these findings should inform policy making, encouraging strategies to curtail meat production and consumption. However, this proposition has already sparked debate.
In a recent Commons committee hearing on food security, Farming Minister Mark Spencer stated a preference for enhancing meat production efficiency over dictating dietary choices. He highlighted a yearly 1% efficiency improvement in agriculture and a vision for genetically-modified cows emitting less methane.
Green MP Caroline Lucas challenged Spencer’s view, criticizing the government’s reticence in promoting vegetarianism as “perverse.” She pointed to what she perceives as governmental “double standards” for levying taxes on sugar, tobacco, and alcohol, yet exempting meat.
“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,” said Lucas.