Earth Day Quiz | Climatic meal

From field to plate, the entire food production chain accounts for around a third of global greenhouse gas (GHG) emissions, reports the Food and Agriculture Organization of the United Nations. Which foods have the most impact on the climate? On this Earth Day, here is a quiz to test your knowledge.

The plate of the average Quebecer is responsible for what proportion of his individual GHG emissions?

A) One tenth

B) Quarter

C) The third party

Answer: B

The International Reference Center for the Life Cycle of Products, Processes and Services (CIRAIG) has calculated, in 2020, that the average Quebecer buys 1236 kg of food per year. This represents annual emissions of 2.5 tonnes in “CO equivalent₂ (COeq₂), or a quarter of the individual GHG emissions of an average Quebecer each year. This portrait is correct, because it takes into consideration the entire food chain: from agricultural production to transport, including packaging and food waste. This is called life cycle analysis. An individual’s outcome can, however, differ significantly depending on age, sex and diet.

Taken on a planetary scale, which diet emits the least GHG emissions?

A) Omnivore

B) Ovo-lacto vegetarian: i.e. a diet without meat or fish, but which includes eggs and milk

C) Vegan

Answer: C

Science is unanimous on the fact that beef is the food that produces the most GHG emissions. Cows and bulls are ruminants and therefore their digestive process releases a lot of methane into the atmosphere. But the other animal proteins are not to be neglected. According to a study published in the scholarly journal nature food in September 2021, globally, global GHG emissions from animal-based foods are twice those from plant-based foods. This large study quantified emissions related to the production and consumption of 171 crops and 16 animal products in more than 200 countries between 2007 and 2013.

Cheese or chicken? Which food produces the least GHG emissions?

A) Cheese

B) Chicken

Answer: B

Cheese has a substantially larger carbon footprint than chicken. For example, in France, cheddar cheese emits 5.94 kg COeq₂ per “kilogram (kg) of product” against 1.84 kg COeq₂ per kilogram of chicken. These data come from Agribalyse, a public database developed by France’s Ecological Transition Agency and the National Research Institute for Agriculture, Food and the Environment. They take into consideration all stages of the product life cycle. These data point in the same direction as an extensive meta-analysis of 1530 studies published in Science in 2018. According to this scientific article, taken on a global scale, cheese has a carbon footprint of 23.88 kg COeq₂ per kilogram versus 9.87 kg COeq₂ per kilogram for poultry meat. How can this significant discrepancy between the two data sets be explained? Deforestation, use of chemical fertilizers, agricultural machinery, productivity of fields and animals: agricultural systems vary enormously from one country to another. The study of Science has consolidated data from 38,700 farms and 1,600 processors, packers and retailers across the world. The authors (Poore & Nemecek) note that for the same product, the carbon footprint can vary by a multiple of 50. But one reality remains the same everywhere: the digestive process of cows emits methane.

Pork skewer or lamb skewer? Which meat has the biggest carbon footprint?

A) Lamb skewer

B) Pork skewer

C) They are roughly equivalent

Respond to

According to calculations made by Agribalyse, a raw lamb skewer is responsible for the release into the atmosphere of 52.03 kg COeq₂ per kilogram versus 6.95 kg COeq₂ per kilogram of raw pork. Like the cow, the sheep is a ruminant which emits methane during its digestion, which is not the case for pigs. The trend is the same if we look at global data. The meta-analysis published in Science measured that 1 kg of “lamb and mutton” emits on average 39.72 kg COeq₂ against 12.31 kg COeq₂ per kilogram for pork. In Quebec, the Pork Farmers’ Union has calculated that in 2019, GHG emissions represented 3.70 kg COeq₂ per kilogram of pork. The figure takes into account all the stages of agricultural production: from the cultivation of grains for the feed to the exit from the slaughterhouse, but it excludes the rest of the chain such as transport. It should be noted that Quebec produces more pork than it consumes: approximately 70% of production is exported. Conversely, in 2020, approximately half of Quebec’s lamb consumption was local. The rest came mainly from New Zealand or Australia, which weighs down its balance sheet.

Orange or banana? What is the best fruit for the climate?

A) Orange

B) Banana

C) Their impact is comparable

Respond to

Bananas emit about three times more GHGs than oranges. According to the French Agribalyse database, the carbon footprint of an orange is 0.64 kg COeq₂ per “kilogram of product”, while a banana emits 2.17 kg COeq₂ per “kilogram of product”. The meta-analysis published in Science stresses for its part that on a planetary scale, citrus fruits emit on average 0.39 kg COeq₂ per kilogram and bananas, 0.86 kg COeq₂ per kilogram.

Jujubes, dark chocolate or potato chips? Which treat has the worst carbon footprint?

A) Jujubes

B) Dark Chocolate

C) Chips

Answer: B

Touted for its antioxidant properties, dark chocolate is the treat with the heaviest carbon footprint. According to the Agribalyse database, “dark chocolate with 70% cocoa” emits 17.11 kg COeq₂ per kilogram of chocolate. This is far ahead of “gummy candies” (1.57 kg COeq₂ per kilogram) and “standard potato chips” (1.54 kg COeq₂ per kilogram). Data from the meta-analysis of Science are even worse: 46.65 kg COeq₂ per kilogram of “dark chocolate”. Globally, this footprint is larger than that of dairy cattle (33.30 kg COeq₂ per kilogram of milk) and coffee (28.53 kg COeq₂ per kilogram of coffee). About two-thirds of the cocoa consumed worldwide is grown in West African countries. Cocoa cultivation is, however, one of the main causes of deforestation in this region. When trees are cut down to make way for agriculture, the trees rot or are burned. Instead of being carbon sinks, trees release it into the atmosphere.

Oats, almonds or soy: which vegetable drink has the best carbon footprint?

A) Oat drink

B) Almond drink

C) Plain soy beverage

D) Their impact is comparable

Answer: D

In terms of climate change, their impact is roughly comparable. In the fight against vegetable drinks: the natural almond drink has a slightly smaller footprint (0.37 kg COeq₂ per kilogram of product) than plain soy beverage (0.44 kg COeq₂ per kilogram of product) and plain oat drink (0.54 kg COeq₂ per kilogram of product). In contrast, the almond drink has come under fire in recent years for its other environmental impacts. It is a production that requires astronomical quantities of water in addition to requiring the spreading of pesticides that harm the pollinating insects necessary for their cultivation.

To achieve the objectives of the Paris agreement aimed at keeping the average increase in temperature on earth below 2°C, is it better to work on changing agricultural practices or reducing the consumption of animal proteins?

A) Modify our agricultural practices

B) Reduce the consumption of animal proteins

Answer: B

Better management of manure, change in animal feed, reduction in the use of nitrogen fertilizers, better use of pastures, increased yields on the same area, heating of greenhouses with hydroelectricity rather than oil: the list measures to reduce GHG emissions in agriculture is very long. The EAT CommissionLancet – a famous report by international experts published in 2019 – tried to determine how to feed 10 billion people healthily by 2050 without destroying the planet. She concluded that changes in agricultural practices could reduce agricultural GHGs in 2050 by 10%, while an increase in the adoption of predominantly plant-based diets could reduce emissions by up to 80%. .

Sources: Agribalyse database; “Reducing food’s environmental impacts through producers and consumers”, J. Poore and T. Nemecek, Science, 2021; Our World in Data; EAT CommissionLancets; Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods, Xu, X., Sharma, P., Shu, S. et al. nature food 2724-732 (2021)