If you are devoted follower of our blog, you might have noticed that some of our authors (including myself) helped to organize a museum exhibition about climate change in the last year. Apart from organizing it, most of us also led visitors through the exhibition and discussed with them the causes of climate change, possible impacts on future generations and what each of us can contribute to prevent the most adverse effects of a changing climate.
One thing that frequently puzzled visitors were the results of the so-called “choice game”. With the help of the choice game we wanted to show visitors which areas of our life generate the most carbon emissions and that making smart choices can go quite a way in reducing our personal contribution to a warming planet. We also asked them to pick what they believe is the most environmental-friendly food. Many visitors immediately pointed their fingers at veggies and dairy products. At the same time, they suspected meat and fish to have the worst footprint of all possible choices. When we eventually lifted the curtain, people were often surprised of what they saw: in terms of carbon emissions, the consumption of cheese turned out to be similarly damaging to the environment as eating meat. But why is that?
Let’s take a look at the hard facts first. According to a life-cycle analysis carried out by the US-American non-profit organization Environmental Working Group (EWG), lamb and beef production and consumption by far cause the most GHG emissions per consumed kilogram. Surprisingly, cheese ranks third and scores worse than pork, salmon, turkey and chicken. A study by the United Nations Food and Agriculture Organization arrives at very similar results.
There are several reasons for the relatively large carbon footprint of cheese. First, one kilogram of cheese requires up to 10 kilograms of milk due to the maturing process that cheese usually undergoes. The milk, in turn, comes from a dairy cow. Cows are ruminants that emit large amounts of methane which is about 25 times more damaging to the climate than carbon dioxide and mainly responsible for the comparatively high GHG emissions associated with producing cheese. According to Finnish scientists, figures do not change if the milk comes from sheep or goats. To the contrary, sheep emit even more methane than cows and goats do.
But should you feel depressed now if you are a cheese loving vegetarian because of environmental concerns? Rather not. Although profound research is lacking, the carbon footprint of your diet definitely improves when mainly eating low-fat and soft varieties of cheese, such as mozzarella, feta, brie or camembert. These kinds of cheese necessitate a much less emission-intensive production process due to shorter (or even no) aging. As a rule of thumb, the younger the cheese the better its environmental footprint. Sourcing your cheese from local farmers helps as well. Eventually, one should not forget that cheese is usually not eaten in large quantities. While it is common in many cultures to have a big piece of meat on your plate, few people eat a whole wheel of cheese at once (and it’s apparently not fun either).
Further readings:
1 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4372775/
2 – http://clean-water.uwex.edu/pubs/pdf/CF-Cheese.pdf
3 – http://shrinkthatfootprint.com/food-carbon-footprint-diet
Climate Footnotes 
Such a great post! It is also interesting that the LCA seems to make pork and cheese similar (again, in a /kg form). I was surprised that eggs are so much lower. Is this because chickens are not ruminants?
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First, I am a biologist and I seriously think that the problem of CO2 increase and as a result of this climate change is a real problem and has to be taken seriously.
However there is a deep confusion in the heads.
People are not aware of the details of the carbon cycle(s) and introduction of CO2 emission as a new money messes things up!
Note1:
A distinction must be made between CO2 deriving from stores and CO2 deriving from living material!!! The previous will release CO2 in the short and long term, but the latter is not a carbon source in the long-term!
When I eat something or burn wood in my garden I am, in the short term, adding CO2 to the atmosphere. BUT, this is coming from carbon that had been absorbed by plants in the near past and it will be reabsorbed soon. So in the long term (unless we kill all plants, see my second argument later) this does not count as CO2 emission (well the methane coming from cows is a different thing). If I do not eat or burn that plant it will be decaying through microbial action and WILL PRODUCE THE SAME AMOUNT OF CO2, just slowly!!! SO there is no difference whether I eat it or burn it and in the long-term will not contribute to CO2 increase.
Therefore planting a lot of tree is not solving long term problems either, because a forest fixes CO2 only until it is growing. As soon as it gets into equilibrium it is not increasing the C storage, since decaying wood releases CO2. Only if we manage to help these forest to fossilize can we extract CO2 in the long term.
When I fuel my car with fossil fuel that is a totally different business, it contributes to CO2 level in the long term (if I use biofuel then not, see the argument above)!
Note 2:
When we calculate the environmental impact of food, we have to count not only CO2 emission, but the area needed to grow 1kg of anything! What needs more hectares? 1kg cheese, 1kg, cabbage or 1kg meet?
It is relevant, not only because nature is nice and we have to preserve diversity and rain forests, but because carbon from natural ecosystems (forests, grasslands, etc) slowly leaks into water and very slowly fossilizes on the sea floors (or in local carbon traps). The more area is used by agriculture the less amount of C is extracted from the system!
Attila Gulyas
biologist
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Thanks a lot for this comment and the additional information from the perspective of a biologist. I totally agree that we should also look at the environmental footprint (literally) of our food.
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Really good comment! I totally agree with the fossilizing of trees to remove CO2 from the atmosphere. Is anybody doing this?
For the forests in equilibrium, I believe trees always continue growing, right? It makes no sense to me that there would be zero-CO2-absorption forests …
For the “dynamic-CO2” you justify the reason of measuring and controlling by saying that there needs to be lands to cultivate, and those lands usually come from burning forests which liberate CO2 into the atmosphere, so I’d say let’s not overcomplicate things and trust that by becoming vegetarian and reducing the consumption of cheese we will largely contribute to the planet.
I would also say that we need to reduce the population of the planet. It is crazy that couples are still having more than 2 children and that many families are having more and more pets. This is a problem of economy. If we would have a tenth of the population of the actual World and / or the population would be diminishing instead of increasing, this type of publications would make no sense.
We either adapt as a species or die.
Rich people could think that climate change will kill only poor people and that, based on that, the population would diminish and they could continue with their happy lives, but this is totally untrue since more money we have more we consume, so rich people that eat healthily and have fancy foods and waste large amounts of food and travel and buy all sorts of stuff are largely more pollutant than poor people.
It is a no-brainer: we need to stop consuming all types of resources as we were the only ones in the Planet that matter and economy can and will adapt to that new reality.
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I find your article, including the links, helpful. Thank you! I think the graph (reproduced from ewg) would be even more helpful if it showed kg CO2 per kg dry weight of food. The foods in the graph differ widely in percent water, so that makes the graph somewhat misleading. Even more useful would be a graph showing kg CO2 per kcal of food, and even better than that would be kg CO2 per kg protein in the food. I don’t know if anyone has put together such a table or graph. (I believe the data is available; someone just needs to do the math and make the table.) We get calories, and to a greater or lesser extent fat and other things in these foods that affect their taste and nutritional value, but when we compare cheese vs meat vs alternatives, I think we are looking at them mainly as sources of protein in the diet.
I question whether there is really much benefit to the environment from eating soft, fresh cheeses instead of hard, aged ones. Most of the difference, when comparing them using kg of food consumed, is due to the difference in water content. The soft, fresh cheeses might be up to 80% water, while the hard, aged cheeses might be only 30% water (http://www.ikonet.com/en/visualdictionary/static/us/classification_cheeses). So the difference in carbon footprint between types of cheeses would be much less, or might even disappear altogether, if we compared them using dry weights. The Slate article you link to says that the harder, aged cheeses use more energy in “cooking” the cheese, and in aging it, especially in the US, where below-ground aging rooms without artificial cooling systems are used less often than in Europe. But I wonder whether the possibly higher energy consumption in making a hard cheese is not counterbalanced by the lower energy consumption in transporting it (for the same dry weight, less water content is transported in a hard cheese than in a soft cheese). And at the destination (supermarket, home, restaurant, …) less energy is spent per day in cooling the water content of the hard cheese, which takes up less space in the refrigerator per kg dry weight.
David Sirkin
medical doctor, biologist, engineer
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