Climate change, water shortages, rising global pollution levels and food insecurity have made environmental sustainability the most pressing concern of our time. Improvements in production systems and agriculture, and advances in clean technology will certainly help, but as the global population becomes more conscious of the issues facing us as a human race, we begin to ask ourselves what it is that we can do to help preserve our planet for centuries to come. More than in anything else, the answer to that lies in the diet choices we make.

I, for one, am an occasional “Pescatarian”. This may sound strange, but what that means is that I do not eat any meat, but I do on special occasions eat fish. I mainly survive on fruits, vegetables, soya protein products and non-meat animal products such as dairy and eggs. On top of the usual Omnivores, Vegetarians, Vegans (and of course the Near-Carnivores) among the human race I have recently learned of some other “arianisms” that help to categorise our eating habits. One of my friends described herself as a Flexitarian, meaning she is flexible with her vegetarianism and occasionally chooses meat or fish and another as a Locatarian who chooses only locally produced meat, fish or vegetable products. While a third could be described as a Poultretarian in that she eats no meat or fish except for chicken (but still indulges in other animal products such as cheese and eggs). I would categorise some as Travelatarians as they choose a vegetarian diet whilst travelling to avoid bad meats and resulting stomach bugs. There are also Micro- and Macro-biotarians, Fruitarians, Rawtarians, Lactotarians, Ovolactotarians, semi-Vegetarians and weird and wonderful combinations thereof.

Having said that, overall the world per capita consumption of animal and fish products is rising at unprecedented rates (especially in the last decade or so) as countries reach higher levels of affluence (1). As I shall demonstrate, meat has by far the worst environmental effects, so assuming that majority of readers will be keen meat-eaters who are not worried about the origin or organic status of their food, I will demonstrate what beneficial effects we could bring to the environment by making small changes in different ways.

A UK average citizen consumed 218 g of meat per day in 2002, whilst a typical American citizen ate around 430g of meat and fish per day (2). While meat consumption in advanced countries has stabilised, in all developing countries it is rapidly on the rise. Meat production is incredibly energy intensive and it is estimated that if the whole world reached US consumption levels (where food production uses 50% of all land area, 80% of fresh water and 17% of all fossil fuels) (3), then proven worldwide mineral oil reserves would last about 12 years in supplying food production and consumption alone (4). The emissions attributed to livestock production come not only from the growing of animal feed, but also methane from the animals´ digestive systems and production and transportation of feed and meat. In addition, there are adverse effects for humans as the use of (often preventative) antibiotics in animals promotes antibiotic resistance in humans (5). Non-meat animal products such as eggs and cheese have a lower impact, but are still much more destructive than fruits and vegetables.

With some of the facts and figures laid out, let us now move on to the fun and interesting bit of showing what effect it would have if you were to turn to one of the other “anianisms” I described at the beginning, making comparisons with plant-based diets whilst highlighting some things to consider and dispelling some popular myths.

Option 1: Turn a Complete Pescatarian (replace all your meat calories with fish ones)

Since terrestrial products make up 99% of human food, turning pescatarian may seem like a good option as it takes pressure off land and water resources. However, there are some things in need of consideration when making your fish choices. In Western Europe trawler fishing is the most widespread method and global captured fisheries produced 96 million tonnes of wild fish in 2000  (6). To catch 1kg of fish requires 34 litres of fossil fuels and conserving it adds an extra 0.5-1.5 litres, so to produce 1 g of fish protein requires 14 times the fossil fuel input than to produce 1g of vegetable protein (7). Other methods are more sustainable (for example gillnet fishing needs only 0.65 times energy than veg protein), but nevertheless from a resource depletion perspective our oceans are in crises.

As a result, global aquaculture production (fish farms) has nearly doubled in the 1990s to 45mn tonnes produced in 2000 (8). A popular myth is that by choosing Scottish farmed salmon over wild Alaskan varieties you are helping to alleviate the pressure off wild stocks of fish. In reality, fish farms of carnivorous fish such as salmon and trout do more harm than good since 70% of all fish caught in the wild are now consumed by aquaculture and 4 kg of wild caught fish is required to produce just 1 kg of farmed salmon (9). Intensive fish farming is not the solution to stock depletion, rather better farming practices are. Do not despair however, as a fish lover there are several things you can do to help. You can pay more for sustainably caught wild fish such as line caught tuna and diver caught scallops, alternatively join the fight for more sustainable fish practices – believe it or not one of the best solutions brought forward by a recent WWF report to improve fish farms is indeed to make our salmon and trout vegetarian and feed them plant instead of fish oils (10). 

Option 2: Save food miles and go Locatarian

The concept of Food-Miles has been somewhat of a buzz phrase with media and policy makers alike. Reducing how far a food product travels from its production to its consumption can help reduce the Green House Gas (GHG) emissions from it. A study in the US (11) indeed confirmed this and the researchers estimated that by going completely local would make energy saving equivalent to driving 1,000 miles (approximately the length of New Zealand). It is worth bearing in mind that this is not always strictly the case. A study in the UK showed that an energy saving would only be made between driving to a local farm to pick up organic vegetables and having them delivered by UK´s largest organic veg-box distributor Riverford if the round trip to the shop and back was made in less than 6.7km (12).

Option 3: Go Organic

There are several advantages to organic farming. Livestock production in the US alone is responsible for 37% pesticide use, 50% antibiotic use and 33% of nitrogen and phosphorus release into freshwater sources (13). Antibiotics, hormones, chemicals from tanneries, fertilizers and pesticides used for feed and other crops make farming and agriculture the largest sectoral source of water pollution in the world contributing to eutrophication, “dead zones” in coastal areas, human health problems and so on (14). Elimination of all these substances would have a hugely beneficial effect for human and natural health and help reverse soil degradation.

One study (15) calculated an aggregated Eco-points score taking into account various environmental and human health effects when looking at organic versus integrated (half organic half normal) production methods. They found that organic fruit and vegetables had the best Eco-scores, followed by organic meat which outperformed integrated methods fruits and vegetables, with integrated method meat production having the worst effects. However, unless you are willing to also reduce your meat consumption, land availability issues would not be solved since organic farming is much less intensive with lower yields. Organic diets are more expensive, but if more people turned to organic simple laws of supply and demand dictate that with time as production increases prices will fall, thus benefitting everyone.

Option 4: Flexing your meat intake

Forgoing meat for just one day a week can have the same effect as going completely locatarian (16).

Option 5: Switch to Chicken

Although other meat than beef and non-meat animal products still have a larger environmental effect than vegetables (for water requirements of different products see graph 1), giving up meat for one day per weak to other animal products would save 760miles (more than driving the entire length of Great Britain, which is only 710 miles). Switching from meat to other animal products altogether and becoming a poultretarian would save around 5,340 driven miles (17), equivalent to driving across the whole of Russia from East to West.

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