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M-3C.2 - Shift to Sustainable Healthy Diets

Mitigation Target

The primary goal is for a shift to an effective average level of healthy diet (global dietary guidelines for consumption of red meat, sugar, fruits and vegetables, and total energy intake).

Mitigation Potential

Feasible potential 1.7 (1.0–2.7). Technical potential 3.5 (2.1–5.5). Estimates reflect direct mitigation from diverted agricultural production only, not including land-use effects.

The total potential for shift to sustainable healthy diets is estimated to be 3.6 (0.3–8.0) Gt CO₂-eq yr–1 and can be broken down into:

  • Full value chain: 3.6 (0.3–8.0) Gt CO₂-eq yr–1
    • \(CH_4\) and \(N_2O\) only: 2.5 (1.5–3.9) Gt CO₂-eq yr–1
      • Agricultural production only: 1.7 (1–2.7) Gt CO₂-eq yr–1

Modelling

This mitigation method has been modelled with the Transition Element: T-3A1-1 - Shift to Sustainable Healthy Diets.

Primary Reference

Critical assessment and conclusion. Shifting to sustainable healthy diets has large potential to achieve global GHG mitigation targets as well as public health and environmental benefits (high confidence). Based on studies to date, there is medium confidence that shifting toward sustainable healthy diets has a technical potential including savings in the full value chain of 3.6 (0.3–8.0) Gt CO₂-eq yr–1 of which 2.5 (1.5–3.9) Gt CO₂-eq yr–1 is considered plausible based on a range of GWP100 values for \(CH_4\) and \(N_2O\). When accounting for diverted agricultural production only, the feasible potential is 1.7 (1–2.7) Gt CO₂-eq yr–1.

- (IPCC AR6 WG3 2022)1

Secondary References

SRCCL

The IPCC report Climate Change and Land (IPCC SRCCL 2019)2 presents the following mitigation potential scenarios:

TODO: get exact figures and ranges for table below:

Diet Potential (\(GtCO_{2}-eq\) \(yr^-1\))
Vegan 8
Vegetarian 6
Flexitarian 5
Healthy diet 4.6
Fair and frugal 4
Pescetarian 4
Climate carnivore 3.4
Mediterranean 3
Vegan: Completely plant-based (Springmann et al. 2016; Stehfest et al. 2009)34.

Vegetarian: Grains, vegetables, fruits, sugars, oils, eggs and dairy, and generally at most one serving per month of meat or seafood (Springmann et al. 2016; Tilman and Clark 2014; Stehfest et al. 2009)354.

Flexitarian: 75% of meat and dairy replaced by cereals and pulses; at least 500 g per day fruits and vegetables; at least 100 g per day of plant-based protein sources; modest amounts of animal-based proteins and limited amounts of red meat (one portion per week), refined sugar (less than 5% of total energy), vegetable oils high in saturated fat, and starchy foods with relatively high glycaemic index (Springmann et al. 2016; Hedenus, Wirsenius, and Johansson 2014)36.

Healthy diet: Based on global dietary guidelines for consumption of red meat, sugar, fruits and vegetables, and total energy intake (Springmann et al. 2016; Bajzelj et al. 2014)37.

Fair and frugal: Global daily per-capita calorie intake of 2800 kcal/cap/day (11.7 MJ/cap/day), paired with relatively low level of animal products (Smith et al. 2013)8.

Pescetarian: Vegetarian diet that includes seafood (Tilman and Clark 2014)5.

Climate carnivore: 75% of ruminant meat and dairy replaced by other meat (Hedenus, Wirsenius, and Johansson 2014)6.

Mediterranean: Vegetables, fruits, grains, sugars, oils, eggs, dairy, seafood, moderate amounts of poultry, pork, lamb and beef (Tilman and Clark 2014)5.

  1. IPCC AR6 WG3. 2022. Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by Priyadarshi R. Shukla, Jim Skea, Raphael Slade, Alaa Al Khourdajie, Renée van Diemen, David McCollum, Minal Pathak, et al. https://doi.org/10.1017/9781009157926. ↩

  2. IPCC SRCCL. 2019. Climate Change and Land: An IPCC Special Report on Climate Change, Desertification, Land Degradation, Sustainable Landmanagement, Food Security, and Greenhouse Gas Fluxes in Terrestrial Ecosystems. Intergovernmental Panel on Climate Change (IPCC). https://doi.org/10.1017/9781009157988. ↩

  3. Springmann, Marco, H. Charles J. Godfray, Mike Rayner, and Peter Scarborough. 2016. “Analysis and Valuation of the Health and Climate Change Cobenefits of Dietary Change.” Proceedings of the National Academy of Sciences 113 (15): 4146–51. https://doi.org/10.1073/pnas.1523119113. ↩↩↩↩

  4. Stehfest, E., Alexander Bouwman, Detlef Vuuren, Michel Elzen, Bas Eickhout, and Pavel Kabat. 2009. “Climate Benefits of Changing Diet.” Climatic Change 95 (February):83–102. https://doi.org/10.1007/s10584-008-9534-6. ↩↩

  5. Tilman, David, and Michael Clark. 2014. “Global Diets Link Environmental Sustainability and Human Health.” Nature 515 (7528): 518–22. https://doi.org/10.1038/nature13959. ↩↩↩

  6. Hedenus, Fredrik, Stefan Wirsenius, and Daniel Johansson. 2014. “The Importance of Reduced Meat and Dairy Consumption for Meeting Stringent Climate Change Targets.” Climatic Change 124 (May):79–91. https://doi.org/10.1007/s10584-014-1104-5. ↩↩

  7. Bajzelj, Bojana, Keith Richards, Julian Allwood, Pete Smith, John Dennis, Elizabeth Curmi, and Christopher Gilligan. 2014. “Importance of Food-Demand Management for Climate Mitigation.” Nature Climate Change 4 (August):924–29. https://doi.org/10.1038/nclimate2353. ↩

  8. Smith, Pete, Helmut Haberl, Alexander Popp, Karl-Heinz Erb, Christian Lauk, Richard Harper, Francesco Tubiello, et al. 2013. “How Much Land Based Greenhouse Gas Mitigation Can Be Achieved Without Compromising Food Security and Environmental Goals?” Global Change Biology 19 (February). https://doi.org/10.1111/gcb.12160. ↩