Are Plant-Based Diets Really Good for the Planet?

Recently, the popularity of plant-based diets has grown significantly all around the world. Roughly 10% of Australians in 2021 have adopted a plant-based diet. While in Portugal, the number of plant-eaters has increased by 400% in the last decade. Fully plant-based diets are difficult to transition into and therefore smaller goals are usually set before making the leap. For example, the Chinese government has released dietary guidelines to encourage the Chinese population to reduce their overall meat consumption by 50%. However, a completely animal-free diet is a practice most popular in the United States and the United Kingdom.

One of the motivations behind plant-based dietary changes is the claim of improving one's own environmental impact. There is no doubt that meat-based diets make huge contributions to the planet’s greenhouse gas emissions. According to the Food and Agriculture Organization of the United Nations, beef and milk alone contribute to 41% and 20% of emissions of the planet’s greenhouse gas outputs, and that excludes emissions produced from manure and other secondary sources.

A recent report by the EAT-Lancet Commission states that even the “greenest” sources of meat still produce more greenhouse gases than plant-based proteins. But does this mean the switch to a plant-based diet is the right way to go if we want a healthier environment?

While it is generally true that industrialized animal farming incurs huge environmental costs in comparison to plant farming, there are a few things you need to consider if you’re vegan or thinking about going vegan.

Alternative Milks

According to BBC News, a single glass of almond milk requires 74 litres of water and produces 0.7 kg of carbon dioxide per litre produced. The production of soy milk emits about 1 kg of carbon dioxide per litre, even more than almond milk, but requires less water and land in its production. Rice and oat milk emit 1.2 kg and 0.9 kg of carbon dioxide per litre, respectively. Even though these numbers are lower than dairy milk, which emits a staggering 3 kg of carbon dioxide and requires 628 litres of water to produce a single litre, the consumption of the plant-based alternatives is still not very good for the environment.

Imported Fruits and Vegetables

Studies show that plant-based diets tend to have lower carbon and ecological footprints than diets that mostly consist of dairy, meat, and fish. But eating fruits and vegetables, specifically those that are not available locally and are out of season, are disastrous for the environment. A sustainability researcher claims that asparagus eaten in the UK produces 5.3 kg of carbon dioxide for every kilogram of asparagus eaten. This is mainly because it is imported from other countries by air. Blueberries and blackberries are regularly imported to the US and Europe in order to fill in those local gaps and ensure those types of fruits are available in supermarkets all year long. A research assistant at the Food Climate Research Network (FCRN) states that imported fruits and vegetables have a very large carbon footprint, but she also thinks that “food miles” are not always the best measure of a food item’s sustainability, and that intensively-grown local produce can also have as big of a carbon footprint as imported produce; taking into account the water and land space needed for processing and transportation.

Avocados

A single kilogram of avocado requires 30 to 60 gallons of water. This is because the roots of the avocado tree are shallow and are poor at searching for underground water, so it evaporates very quickly and needs to be constantly replenished. This creates huge pressures on local environments where avocados are grown like Mexico, Chile and southern Spain. If that isn’t enough, a study conducted by Carbon Footprint Ltd claims that importing a small pack of avocados from Mexico to the UK produces 0.84 kg of carbon dioxide into the atmosphere.

Palm Oil

From lipstick to pizza dough, margarine to laundry detergent, palm oil is in almost half of the items that you see in the supermarket. It is the most widely-consumed vegetable oil on the planet, because of its high efficiency and availability for manufacturers. However, according to the World Wildlife Foundation (WWF), “its rapid expansion threatens some of the planet’s most important and sensitive habitats.” Palm oil grows in rain forests and is extracted from uncontrolled clearing of these forests, which causes widespread destruction of the habitats of certain endangered species, including elephants, orangutans, and rhinos to name a few.

Vegan Meats

These are the plant-based “alternative meats” that are popping up in fast food restaurants, meal kits, and supermarkets. They are made from a substance called “mycoprotein” and is grown in food labs. An article by BBC states that these meat-alternatives have the potential to dramatically reduce the environmental footprint of food. Even Bill Gates himself calls them the “food of the future.” Their production uses a fraction of the land in comparison to beef and chicken, but one study claims that it emits about 6 kg of carbon dioxide per one kilogram of meat. Quorn, a mycoprotein manufacturer states that to make the mycoprotein itself releases just 0.8 kg of carbon dioxide per kilogram, but to produce the meat product from the mycoprotein, it releases a lot more, and it is mainly due to the energy needed for the whole process.

What now?

Choosing the best diet for ourselves and our planet is tricky. Everything we eat has its carbon footprint, some foods more than others. Reducing our meat and dairy consumption and being cautious about the type and amounts of plant-based alternatives are a good first step, but only for the near future. Being mindful of where what’s in season, where we buy our groceries, and where our restaurants and markets buy their groceries is also important factors in deciding what our diets should be. Plant-based alternative meats are a promising step as well, and who knows, maybe insects will end up being the meat of the future.