In 2011, the Catholic bishops of England and Wales urged congregations to return to the above meat on Fridays. Only around a quarter of Catholics have changed their eating habits – but this has still saved more than 55,000 tonnes of carbon emissions a year, according to a new study led by the University of Cambridge.
The researchers say that in terms of CO2 emissions, this is equivalent to 82,000 fewer people making the return journey from London to New York over the course of a year.
The current Catholic leader, Pope Francis, has called for “radical” responses to climate change. Researchers say that if the pope restores meatless Fridays in the global church, it could mitigate millions of tons of greenhouse gases annually.
For example, they say that if only Catholic bishops in the United States issued a “commitment” to not eat meat on the last day of the working week, the environmental benefits would likely be twenty times greater than in the UK.
“The Catholic Church is very well placed to help mitigate climate change, with more than one billion followers around the world,” said lead author Professor Sean Larcombe of Cambridge’s Department of Earth Sciences. “Pope Francis has already emphasized the moral imperative to act on the climate emergency and the important role of civil society in achieving sustainability through lifestyle change.
“Meat farming is one of the main drivers of greenhouse gas emissions. If the pope restores meatless Fridays to all Catholics around the world, that could be a major source of low-cost emissions reductions,” Larcom said, “even if only a minority of Catholics choose to comply, as we find in our case study.”
Traditionally, the practice of abstaining from meat one day a week has led many Catholics – and indeed large sections of the population in predominantly Christian countries – to turn to fish on Fridays as a substitute for protein.
The overall Catholic share of Britain’s population has remained largely stable for decades at just under 10%, say economists behind the study, published today as a working paper awaiting peer review by Social science research network.
Larcom and colleagues combined new survey data with those from dietary and social surveys to quantify the effects of a statement issued by the Catholic Church for England and Wales reinstating meatless Fridays as a collective act of penance from September 2011 onwards after 26 -year break.
The results of a commissioned survey showed that 28% of Catholics in England and Wales changed their diet on the Friday following this announcement. Of this segment, 41% said they stopped eating meat on Friday, and 55% said they tried to eat less meat that day. For those who said they simply cut back, the researchers suggested cutting meat intake in half on Fridays.
People in England and Wales eat an average of 100g of meat a day, according to the National Diet and Nutrition Survey (NDNS). Researchers estimate that even a small reduction in meat intake by a proportion of the Catholic population is equivalent to every working adult in the whole of England and Wales removing two grams of meat a week from their diet.
The team then calculated the carbon footprint of this small drop in meat consumption by comparing the emissions generated by the average daily diets of carnivores and non-carnivores in England and Wales. The average high-protein, meat-free diet, including foods such as fish and cheese, contributes just one-third of the greenhouse gas emissions per kilogram compared to the average meat eater.
Assuming that Catholics who adjust their diets switch to protein-rich, non-meat meals on Fridays, this would equate to approximately 875,000 fewer meat meals per week, saving 1,070 tonnes of carbon – or 55,000 tonnes for a year, according to the researchers.
In addition to their central calculation, the researchers used a natural experimental approach in the UK to compare meat consumption in Scotland and Northern Ireland, where Catholic bishops have not tried to reintroduce meat-free Fridays, with that in England and Wales since 2009 until 2019
Using data from the NDNS dietary diary, the team determined changes in mealtimes on Fridays alone and found that meat consumption fell by around eight grams per person in the ‘healing jurisdiction’ of England and Wales after the re-establishment of Catholic duty compared with the rest of the United Kingdom.
There could be many reasons for this dietary change – meat intake has decreased across the country during this time – but the team says the decrease is at least partly a result of the return of meat-free Fridays. As such, they say carbon footprint calculations using a drop of two grams per week are likely to be conservative.
The researchers also tested for “religious effects” using data from longitudinal surveys that asked British Catholics about their religious lives. No noticeable effect was found on either church attendance or the strength of personal religious beliefs during the period when meatless Fridays were reintroduced.
“Our results highlight how a change in diet among a group of people, even if they are a minority in society, can have very large consequences for consumption and sustainability,” said co-author Dr Po-Wen She, a fellow at Cambridge’s Department of Land Management .
Co-author Dr Luca Panzone from the University of Newcastle added: “Although our study looks at a change in practice among Catholics, many religions have dietary prohibitions which are likely to have a large impact on natural resources. Other religious leaders could also induce behavioral changes to further promote resilience and climate change mitigation.”
For Christians, the practice of meatless Fridays dates back to at least the declaration of Pope Nicholas I in the 9th century. Catholics were required to abstain from eating meat (“flesh, blood, or marrow”) on Fridays in commemoration of Christ’s death and crucifixion.
However, fish and vegetables, along with crabs, turtles and even frogs were allowed. Researchers point out that the practice was so fervently observed among some American Catholics that it led to the invention of the McDonald’s burger chain’s Filet-o-Fish meal.
Food for Soul and Planet: Measuring the Impact of the Return of Meatless Fridays for (Some) Catholics in the UK Social science research (2022).
Quote: Catholic Church could cut carbon emissions by returning to meatless Fridays, study suggests (2022, 31 October) Retrieved 31 October 2022 from
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