The Impact of Cheesecheeses

Hello, I’m Finlay – an ex-full-time carnivore, recently turned Flexitarian.

As somebody that’s interested (I assume) in a flexitarian diet, I imagine you’re already well aware of the multi-faceted benefits of reducing meat consumption. Personally, the sole fact that removing meat from my diet could reduce my personal greenhouse gas (GHG) emissions by over a third [1] was reason enough for me to give meat reduction a bash.

I have a passion for cooking and this transition was surprisingly easy. In fact, it invigorated me in the kitchen as I sought out and trialled novel recipes with a new found spring in my spatula.

I swapped my regular weekday chicken salad lunches for Mediterranean feta, beetroot and houmous affairs and traded my evening meals of meat-based curries and middle-eastern dishes for more vibrant, multi-dimensional vegetable alternatives.

However, after a few weeks something began to catch my attention – I had seemingly replaced my old reliance on meat with a new reliance on cheese at the core of many of my dishes. On reflection, this was not a huge surprise. Cheese is a flavoursome protein source and an often salty, fatty, savoury alternative to centre a dish around. For a novice meat-free cook, this was an obvious path to take. But how does it weigh up against meat?

Could replacing meat with cheese cancel out the benefits of a flexitarian diet?

I mentioned GHG emissions earlier but I’d also hoped that my new dietary choice would be having a positive impact on:

  • Personal health
  • Animal welfare
  • Land, water, pesticide and energy use
  • Environmental soil, water and air pollution

Was this really the case?

As I began to do some research, it quickly became clear that such questions were not only complex, but that online articles covering this subject were few and far between. In essence, for a non-scientific member of the public, such information is not readily available or accessible.

While recognising the many additional impacts detailed above, for simplification, I will focus on the climate change impact here i.e. the GHG emissions associated with consuming cheese.

One, well presented source is the ‘Meat Eater’s Guide’ produced by the Environmental Working Group (EWG) [2]. This report found that 13.5 kilograms (kg) of Carbon Dioxide equivalents (CO2e) were produced per kg of cheese consumed. This is compared to 39 kg for lamb, 27 kg for beef, 12 kg for pork and farmed fish (salmon), 7kg for chicken and 5kg for eggs [2].

Figure 1: Full Lifecycle Greenhouse Gas Emissions from Common Proteins and Vegetables [2]

green_house_proteins graph

For comparison, a study from the University of Wisconsin-Madison found that the average US production of cheddar generated 8.4 kg CO2e per kg of cheese [3]. Despite this value being lower, it’s interesting to note that it’s still higher than chicken!

Why are these figures so high?

The answer stems from the same reason that lamb and beef consumption ranks so highly. Cows (and sheep) are ruminant mammals that possess four compartments in their stomachs. These are used to continually regurgitate food and break it down using microbes located in one of the compartments known as the ‘rumen’. These microbes produce methane called ‘enteric methane’ which is then expelled to the atmosphere – mostly through burping! Importantly, Methane (CH4) has about 25 times the global warming potential of CO2 [3].

While enteric methane from rumen is the major source of GHG emissions from beef and dairy farming, the methane emitted from manure also contributes, as does Nitrous Oxide (N2O) emitted during the laying of fertilizer or manure on fields to grow feed for the cattle.  N2O has about 300 times the global warming potential of CO2. While processing, packaging, transport and wastage also have an effect on the lifecycle assessment of cheese; it is interesting to note that over 90% of GHG emissions from cheese are attributed to the milk production stage [3].

For environmentally minded cheese lovers, these findings make for dismal reading. Even by sourcing locally and minimising waste in the kitchen – it appears cheese consumption is doomed to leave a large carbon footprint on the planet.

Does the type of cheese matter?

Another study which directly investigated the impact of cheddar and mozzarella found that a kg of cheddar was responsible for 8.6 kg CO2e compared to 7.28 kg CO2e from mozzarella [4]. This demonstrates that the emissions related to different types of cheeses can vary significantly.

As a rule of thumb, the longer the cheese has been aged, the higher its environmental impact, due to the greater energy requirement. Likewise, if a cheese is hard, it will likely have required more milk to produce, have been aged for longer and required additional cooking – all contributing to increased GHG emissions. As such, young, soft cheeses such as cottage, feta, chèvre, brie, camembert and mozzarella are more environmentally friendly while older, harder cheeses such as extra mature cheddar or parmesan will be worse [5].

It’s also worth mentioning a potentially misleading aspect of the studies I have cited so far: the values of kg CO2e calculated are per kg of produce and do not account for nutritional density of the food. For example, a chicken breast contains around 18% protein, beef 36%, pork 30% and eggs 13% [6]. Compare this to the 42% protein present in parmesan, 28-32% in mozzarella, 25% in Edam and 20% in Camembert [7], and it’s clear the kg CO2e figures are not a totally fair comparison. A small amount of cheese can go a considerable distance.

With this in mind, it’s worth concluding that the best way to minimise your carbon footprint is clearly to minimise your consumption of cheese where possible. In terms of GHG emissions, cheese should be treated as you would chicken or pork – replacing such meat with an equivalent amount of cheese can do more harm than good. However, when cheese is eaten, opt for younger, softer cheese and try to moderate the amount included when preparing a dish. Not only will this be kinder to the planet but for health reasons, will limit the amount of saturated fat consumed and additionally, both nutritionally and flavour-wise, a little cheese goes a long way.

 

 

[1] C. Hoolohan, et al., 2013. “Mitigating the greenhouse gas emissions embodied in food through realistic consumer choices”. Energy Policy 63, 1065-1074. Link

[2] K. Hamerschlag, 2011. “Meat Eaters Guide to Climate Change + Health”. Environmental Working Group. Online: Link

[3] H. Aguirre-Villegas, et al., 2011. “Sustainable Cheese Production: Understand the Carbon Footprint of Cheese”. College of Agricultural and Life Sciences, University of Wisconsin-Madison. Link

[4] D. Kim, et al., 2013. “Life cycle assessment of cheese and whey production in the USA”. International Journal of Life Cycle Assessment 18, 1019–1035. Link

[5]N. Rastogi, 2009. “Soft Cheese for a Clean Planet. A foodie’s guide to planet-friendly fromage.” Slate. Online: Link

[6]HealthAliciousNess. “Top 10 Foods Highest in Protein (Ranked by Protein/Calorie Ratios)”. Online: Link

[7] HealthAliciousNess. “36 Cheeses Highest in Protein”. Online: Link

The Impact of Cheese