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Your personal CO2e budget to stay below 2℃

Posted at 2021-04-05 12:35:59 by Matthew

On average, a European or American citizen is estimated to emit 5-8 kg of CO2e per day on food.1,2,3,4 Surprisingly, the world's average is not much lower at an estimated 4-5 kg of CO2e per person per day., For reference, the category "Food" typically corresponds to 20-30% of a citizen's total CO2e emissions, with each of the other 3 main categories "Travel", "Home" and "Goods and Services" contributing 20-30% as well, both in Europe/America1,2,3,4 and worldwide.5,6,7

Many developed countries aim to be climate neutral by 20508,9, which would limit global warming under 2℃ according to current projections.10 Following this ambition, our personal aim should be to limit our global greenhouse gas emissions for food to 2.7 kg CO2e per day by 2030.11 This would mean a need for a 2-3 fold decrease in average daily food CO2e emissions for a European or American and a 1.5-2 fold decrease worldwide.

On LiveLCA.com, we use this 2.7 kg CO2e per day personal aim as a yardstick to make the emission numbers easier to interpret. For example, this 2.7 kg CO2e corresponds to approximately
- 1 kg eggs (=15-20 eggs depending on the size), or
- 400 grams pork, or
- 100 grams beef, or
- 7 kg potatoes, or
- 1 portion of lasagna, or
- 3 portions of faux-meat lasagna, etc.

Currently, even a vegan diet is estimated to emit 3-4 kg CO2e per day, and a meat heavy diet is estimated at more than double that with 7-9 kg CO2e per day.12,13 Fortunately, greenhouse gas emissions can be expected to diminish in food production and supply chains over the next decade, for example with innovations in agriculture, transport and transitions to renewable energy.

Data summary: https://docs.google.com/spreadsheets/d/1lhDKpjSlsreun1chP6nHIxL37AIAuq1uYR-sStjk-0A/


[1] Jones, C. M., & Kammen, D. M. (2011). Quantifying carbon footprint reduction opportunities for US households and communities. Environmental science & technology, 45(9), 4088-4095. 5-7 tons CO2e / household (2.5 persons) / year = 5.5 - 7.7 kg CO2e / person / day
[2] https://eaternity.org/foodprint/climate-change: 5.18 kg CO2e / person / day
[3] https://www.2degreesinstitute.org/: 2.8 tons CO2e / person / year = 7.7 kg CO2e / person / day
[4] Ottelin, J., Heinonen, J., Nässén, J., & Junnila, S. (2019). Household carbon footprint patterns by the degree of urbanisation in Europe. Environmental Research Letters, 14(11), 114016. 2.2 tons CO2e / person / year = 6.0 kg CO2e / person / day
[5] https://ourworldindata.org/emissions-by-sector 18.4% * 49.4 gigatonnes / 7.4 billion people / 365 days = 3.3 kg CO2e / person / day. The 18.4% does not seem to include supply chain for food, so this is likely a conservative estimate.
[6] Poore, J., & Nemecek, T. (2018). Reducing food’s environmental impacts through producers and consumers. Science, 360(6392), 987-992. Food emissions correspond to 13.7 gigatonnes (26%) of global GHG emissions annually. 13.7 Gt / 7.6 billion people / 365 days = 4.9 kg CO2e / person / day
[7] http://www.fao.org/3/i6340e/i6340e.pdf "FAO’s work on climate change GHG emissions": 24% of total GHG emissions for agriculture, forestry and other land use
[8] https://ec.europa.eu/clima/policies/strategies/2050_en
[9] https://www.climatechangenews.com/2019/06/14/countries-net-zero-climate-goal/
[10] https://www.mcc-berlin.net/en/research/co2-budget.html: carbon budget left for 2℃ in April 2021 was 1033 gigatonnes (Gt). A linear decrease to 0 emissions in 2050 from 49 Gt / year in 2019 would cap the total carbon emissions at 735 Gt. Note that a linear decrease might not be practically feasible.
[11] https://docs.google.com/spreadsheets/d/1lhDKpjSlsreun1chP6nHIxL37AIAuq1uYR-sStjk-0A/ 33.8 gigatonnes/year / 8.5 billion people / 365 days * 25% (for food) = 2.7 kg CO2e / person / day
[12] http://shrinkthatfootprint.com/food-carbon-footprint-diet vegan diet: 1.5 t CO2e / year = 4.1 kg CO2e / day, meat-lover diet: 3.3 t CO2e / year = 9.0 kg CO2e / day
[13] Scarborough, P., Appleby, P. N., Mizdrak, A., Briggs, A. D., Travis, R. C., Bradbury, K. E., & Key, T. J. (2014). Dietary greenhouse gas emissions of meat-eaters, fish-eaters, vegetarians and vegans in the UK. Climatic change, 125(2), 179-192. High-meat eaters: 7.2 kg CO2e / day, medium meat eaters: 5.6 kg CO2e / day, low-meat eaters: 4.7 kg CO2e / day, pescetarians: 3.9 kg CO2e / day, vegetarians: 3.8 kg CO2e / day, vegans: 2.9 kg CO2e / day.