As you probably know by now, the kind of food we choose to eat has a major impact on climate change, deforestation, pollution, biodiversity losses, water use, and food security. We’ve all received the message that eating plants is better than eating meat. But the extent to which our various food options – protein-rich foods in particular – impact these environmental and social issues has, surprisingly, not been well-covered by the media. These details are obviously important for people who want to reduce their impact on the planet, but can’t immediately switch to a vegan diet (which includes most people). This post will help you see where the biggest differences can be made and to decide between animal-based foods such as cheese versus eggs.

So basically what I’m going to do here is to translate the best science into easy-to-grasp charts that show the environmental impacts of different foods. In my next post, I plan to describe the environmental issues in more detail – the major threats to life on Earth known as Planetary Boundaries. But for now, it’s enough to know that food production (agriculture) is a major factor in almost every major environmental challenge that we face, as we’ll see below.

A note about the data from Poore and Nemecek

The data in the charts below comes from a 2018 paper Reducing food’s environmental impacts through producers and consumers, published in Science by two Oxford University scientists, Poore and Nemecek. It’s the most widely cited and respected research on this topic, to date.

If you do an internet search on the carbon footprint of various foods, you’ll most likely come across a chart from Our World in Data. That chart uses a subset of the data from the same Poore and Nemecek paper that does not include the footprint of wasted food. My chart does include Poore and Nemecek’s adjustment for food waste and correspondsto the data shown in the main figure of their paper. (The raw data is in file aaq0216_datas2.xls, provided here.)

Including an adjustment for food waste is important because it gives a more accurate picture of the environmental footprints but also, importantly, because the amount of waste varies considerably per food type. As the authors pointed out in their paper, “wastage is high for fresh animal products, which are prone to spoilage.” You’re much more likely to allow milk or meat to go off than some dried legumes – even more so for supermarkets, which cannot sell meat or dairy beyond a limited time period. Including the adjustment for wasted food increases the estimated carbon footprint of beef from 60 kg to 100 kg of CO₂ (per kg of beef).

Ok, so let’s get to the data, starting with the carbon footprint!