Animal products, especially meat and fish, have high carbon footprints due to energy and resource intensive practices in agriculture and aquaculture; in addition, many types of fish and shellfish suffer from overexploitation or even depletion.

People living in rich countries, a mere 20% of the total human population, eat 45% of meat and fish consumed throughout the world.

The ocean is the first source of food for more than 3.5 billion people. Within 20 years, the number could increase to 7 billion people.

Red meat

This site does not aim to give nutritional advice but eating less animal products or at least not more than nutrition experts recommend, can significantly reduce your carbon emissions (bearing in mind that one can live healthily on a vegetarian diet). For example, if you eat meat and fish 1-2 times a week (one portion size is around 140 grams, in line with nutrition guidelines) then you will roughly add between 85 kg and 100 kg CO2 per year to your food bill. If you eat meat or fish every day though you can easily add between 112 and 290 kg. The type of meat or fish you eat also has a significant impact on your carbon footprint from food; for example, beef and pork have higher carbon footprints than lamb and chicken.

Note that if other greenhouse gases, in particular methane emissions from cattle are taken into account, results for red meats - particular beef - will increase. For example, the difference in added greenhouse gases for a person on an excessive calorie and meat intake (pork, beef and lamb) and a person living on a plant based diet are comparable to driving a big 4x4 Chevrolet and an efficient Toyota Prius hybrid car.   


Global production of farmed fish and shellfish has more than doubled in the past 15 years. Although many people believe that this growth eases the pressure on wild fish stocks, for some types of aquaculture including salmon and shrimp farming the opposite is true. This is due to potential damage to ocean and coastal resources from habitat destruction, wastes, introduction of exotic species, and spreading of diseases. In particular the high amounts of fish meal and fish oil for feed may further deplete dwindling wild fish stocks.

Some species such as Tilapia can be fed on an entirely vegetarian diet, whilst the majority of UK farmed species are fed a carnivorous diet. The feed for carnivorous fish comprises fishmeal and fish oil derived from wild caught species of small pelagic fish, predominantly anchovy, jack mackerel, blue whiting, capelin, sand eel and menhaden. On average 3kg of wild caught feed grade fish is required to produce 1kg of salmon, and 12kg of fish to produce 1kg of fish oil. Although these figures represent a significant improvement in feeding technology over recent years, the fact remains that farming carnivorous fish relies on wild capture fisheries, and removing a large number of smaller species of fish from the food chain can have adverse ecosystem affects. 

So while the growing aquaculture industry must reduce wild fish inputs into feed and adopt more sustainable management practices you can also help by making more sustainable choices, and finding out more by visiting the WWF website:

The Marine Conservation Society has also produced a guide for buying fish and a leaflet on which fish to buy and which to avoid, along with a FAQ section and a wealth of other information that can be downloaded here:

Also, the Marine stewardship council’s website:

Diary products

Eating more dairy products than you need is also fraught with high emissions (you need to raise the cow first to get the milk). One or two servings of low fat milk, yoghurt or cheese per day is in line with recommendations but will add between 52 kg to 140 kg to your carbon footprint; the latter if it’s cheese! According to a study by the University of Reading, “if everyone in the UK followed official guidelines for healthy eating, consumption of fruit and vegetables would increase by 50%, consumption of cheese would decrease by 75%, meat and milk would decrease by 15% and fats by 20%”.

Organic diet

Most organic produce seems to come with lower greenhouse gas emissions than conventionally produced food. A comprehensive study on organic and conventional agriculture in Australia suggests that conventional farming has around twice the energy consumption and greenhouse gas emissions than organic farming and is also higher in terms of water use, land disturbance, and other environmental impacts when the total supply chain is taken into account. Other studies using different methods, generally support this in terms of greenhouse gas emissions and energy use for some products but not others; however, these results are not conclusive and depend on the assumptions made; in addition, factors such as soil quality and biodiversity need to be taken into account.