How much can the protein transition reduce emissions?

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The shift to a plant-based diet could significantly reduce global emissions, the study suggested. Image Source: Getty Images/Bjorn Holland (Getty Images/Image Source)

Reducing meat intake and shifting towards a healthier diet has the potential to moderate greenhouse gas emissions. But by how much?

Many figures in both industry and policymaking believe that in order to tackle climate change, we need to enter into a ‘protein transition’, a move away from animal-source proteins that are causing abundant greenhouse gas emissions.

One of the solutions to such a problem is the consumption of plant-based foods, and plant-based proteins. But how significant would such a shift really be in tackling the problem?

How much difference could dietary shifts make?

If the world were to adopt the EAT-Lancet Planetary Health Diet, according to a new study in Nature Climate Change, global dietary emissions could be reduced significantly. Focusing on carbon dioxide, nitrous oxide, and methane emissions, it explored the potential of a dietary shift to reduce these emissions.

In order to ascertain this, the study looked at the dietary emissions of 140 products, across 139 countries or areas (approximately 95% of the world’s population). To ascertain income, consumption and asset accumulation, it looked at total expenditure of consumers.

The three main sources of dietary emissions, it found, were grains, red meat and dairy. Grains accounted for 51% of calories, while red meat and dairy accounted for only 5% each. Plant-based sources contributed to 48% of global emissions but 87% of global calories.

The study found that global adoption of the EAT-Lancet Planetary Health diet could reduce emissions by 17% of dietary emissions.

In most of the regions, looked at in the study, animal-based products contribute greater dietary emissions but fewer calories than plant-based products.  

What causes high dietary emissions?

Dietary shifts in affluent countries, according to the study, will have to do a lot of the heavy lifting to reduce significant greenhouse gas emissions. It is affluent people within countries, and affluent countries within the makeup of the world, that produce the most dietary emissions. This is often due to higher red meat and dairy intake.

In high-income countries, dietary patterns are relatively similar across income groups, with an abundance of red meat and dairy consumed by most. However, even in these countries, some of the poorest have red meat consumption below the recommended levels.

The EAT-Lancet Planetary Health diet

The EAT-Lancet Planetary Health diet recommends an abundance of vegetables, around 50% of dietary intake. It recommends a far larger proportion of plant-based proteins than animal-source proteins, for instance.

In large parts of the rest of the world, starchy staple foods predominate. Foods such as grains and tubers, which are low in price but high in carbohydrates, make up a significant portion of diet.

According to the study, the world’s low-income populations moving towards healthier diets would mean an increase in dietary emissions by 15.4%.

The UN’s Food and Agriculture Organisation (FAO) suggests that healthy diets remain unaffordable for a third of the world’s population. According to Nature’s study, this number is around 3.1 billion.

A third of the world unable to afford a healthy diet

Despite the economic recovery following Covid-19, according to the FAO, around 35.4% of the world’s population, or 2.823 billion people, were unable to afford a healthy diet in 2022. This is 64.8% in Africa, 35.1% in Asia and 27.7% in Latin America and the Caribbean. In Oceania this was 20.1% and in North America and Europe it was 4.8%.

However, complementing this, according to the study, 56.9% of the global population are overconsuming. The significant difference that they could make by shifting their diets could offset the increased dietary emissions that poorer populations would create by moving towards healthier diets.

According to the study, they could save 32.4% of emissions by shifting to the EAT-Lancet planetary diet, offsetting the 15.4% increase in emissions stemming from poorer populations shifting towards a healthier diet. The suggested dietary shift, the study suggested, would not only reduce greenhouse gas emissions but has the potential to move 43.1% of the world’s population out of underconsumption.

The countries that would see the most significant decrease would be Uzbekistan (−74%), Australia (−70%), Qatar (−67%), Turkey (−65%) and Tajikistan (−64%). The study suggests that in some countries, such as Mongolia, where access to alternative diets is difficult, dietary shift may not be possible.

Sourced From: Nature Climate Change

'Reducing climate change impacts from the global food system through diet shifts'

Published on: 13 August 2024

Doi: https://doi.org/10.1038/s41558-024-02084-1

Authors: Y. Li, P. He, Y. Shan, T, Li, Y. Hang, S. Shao, F. Ruzzenenti & K. Hubacek