Q&A results: Buy local: 35%, Eat less meat and dairy: 52%, Opt for seasonal and organic products: 14%

Correct answer: 2, eat less meat and dairy.

Many people are unaware of the impact their diet has on global warming, resource depletion and ecosystem pollution. Livestock farming – which results in the slaughter of 60 billion animals every year for human consumption – causes significant damage to our planet, even with organic farming. The main culprits are the pollution resulting from the use of fossil fuels and the production of nitrogen and phosphorus; animal methane; water and land use (the latter of which leads to deforestation); and livestock runoff. Indeed, animal farming is the source of at least 14.5% of greenhouse gas emissions.

Biodiversity loss

According to a report by the United Nations Food and Agriculture Organization, industrial livestock production also plays a major role in biodiversity loss (60% of wildlife has disappeared since 1970, according to the WWF) and water pollution. The report notes that these environmental consequences are made worse by the large-scale production of dairy products, eggs and wool.

A study published in Science in July 2018 suggests that population growth and rising incomes are likely to increase the consumption of meat worldwide, which would in turn exacerbate the environmental impact of livestock production. According to another study, published in Nature, unless we radically change our eating habits – such as by reducing meat consumption by 90% in industrialized countries – the environmental effects of the food system could increase by 50% to 90% in the coming years.

Humans can do a good turn for the environment by consuming less meat, favoring plant-based foods that undergo the least amount of processing possible, and cutting food waste.


Act4Change is EPFL’s initiative to promote a sustainable campus by encouraging all students, teachers and staff to think about the environmental impact of their actions. Its focus this year is on food. From 12 to 30 November, Act4Change is challenging the EPFL community to take some simple steps that can make a real difference. For more information: https://act4change.epfl.ch/