The switch: What happens to GHG emissions if half of meat, milk consumption is swapped with alternatives?

Biggest impact on agricultural input use would be seen in China, sub-Saharan Africa 

By Shagun
Published: Wednesday 13 September 2023
There has been some success in encouraging plant-based diets in high-income countries, where ASF consumption is the highest. Photo: iStock__

Replacing 50 per cent of main animal-sourced foods (ASF) — pork, beef, chicken and milk — with sustainable alternatives like plant-based meats could “almost fully halt” the net reduction of forest and natural land and cut agriculture and land use greenhouse gas emissions by 31 per cent in 2050, compared to 2020, a new research has established. 

The study, published in the journal Nature Communication on September 12, 2023 used sets of hypothetical plant-based ‘recipes’, designed to be nutritionally equivalent to the original animal-derived products. It then used a global economic model for land use to assess the food system-wide impacts of the global dietary shift. 

Food production accounts for a third of the human-caused global greenhouse gas (GHG) emissions and contributes to global land-use change as forests are cut to make way for cattle and the grains needed to feed them. 

Plant-based diets include foods made from plants, mycelium or other non-animal-based ingredients, but developed to mimic the taste and consistency of animal products. 

There has been some success in encouraging plant-based diets in high-income countries, where ASF consumption is the highest. These alternatives accounted for 15 per cent of the milk market in the United States and 1.4 per cent and 1.3 per cent of the meat markets in the US and Germany, respectively. 

If spared agricultural land within forest ecosystems is restored to forest, climate benefits could double, reaching 92 per cent of the previously estimated land sector mitigation potential, according to the report. 

Furthermore, the restored area could contribute to 13-25 per cent of the estimated global land restoration needs under target two from the Kunming Montreal Global Biodiversity Framework by 2030. 

Global environmental impacts in 2050 across scenarios

Source: Feeding climate and biodiversity goals with novel plant-based meat and milk alternatives, Nature Communications

The distribution of these impacts, however, varies significantly across regions, with respect to population size and diets and resulting total demand for ASF and novel alternatives. China, for example, consumes globally the largest share of pork (45 per cent) and chicken meat (15 per cent); the US leads in beef consumption (15 per cent); and India consumes the most milk (21 per cent). 

The biggest impact on agricultural input use would be seen in China and sub-Saharan Africa and South America would see the largest environmental outcomes impact in terms of land restored. 

Similarly, beef substitution provided the largest impact on GHG emissions, land use and biodiversity. About half of the reduction achieved by substituting all four animal products can be achieved by replacing only beef, the authors said. However, chicken and pork substitution will release more cropland, which is clear in the case of China.

What will this substitution achieve?

The research developed an array of five forward-looking scenarios of dietary changes until 2050 that allow for considering different aspects of possible novel alternatives’ market development. 

In the reference (REF) scenario, the authors assumed that changes in ASF consumption patterns follow economic growth. In the others, they consider the replacement of meat and milk by alternative plant-based foods in varying proportions ranging from 10-90 per cent. 

The authors analysed these scenarios using an economic model called the Global Biosphere Management Model that integrates global agriculture, bioenergy and forestry sectors and allows for the exploration of the potential for the carbon sink and biodiversity restoration under additional land-use policy measures. 

The analysis for the REF scenario showed that food demand globally is projected to grow between 2020 and 2050, predominantly driven by higher incomes and larger populations. 

Average per capita consumption of all main ASF products increased, with demand for chicken (+38 per cent) and milk (+24 per cent) growing the most. This also leads to increase in total demand for crops, especially because of higher feed use. 

Further, the agricultural sector exerts pressure on natural resources, as compared to 2020 baseline, with agricultural area replacing 255 million hectare (mha) area of forest and other natural land, nitrogen input to cropland growing by 39 per cent, water use by 6 per cent, GHG emissions by 15 per cent and biodiversity declining by 2.1 per cent. 

In the alternative scenario, all impacts on natural resources decline significantly — global agricultural area declines by 12 per cent, while 653 mha of land is released from use as a result; water use declines by 10 per cent; GHG emissions decline by 31 per cent in 2050 (without accounting for any carbon sequestration on spared land). 

Further, demand for most crops decreases compared to the REF scenario due to reduced demand for feed. The lower demand leads to further price reductions for both crops and ASFs and, through higher food availability, to improved food security. 

The changes are significant by 2050 even with 25 per cent substitution levels. At 50 per cent substitution, the research found even more substantial shifts in most outcomes — total crop production is 20 per cent higher in 2050 compared to 2020, while prices decline 14.1 per cent for animal products and 4.9 per cent for crops. 

The study was done by researchers from the International Institute for Applied Systems Analysis in Austria, the Alliance of Biodiversity and CIAT, USAID Center for Development, Democracy, Innovation and Impossible Foods (a company that develops plant-based substitutes for meat products) in the United States and the Institute for Environmental Studies VU University in the Netherlands.

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