Article Title
Plant-based Diet isn't Best for Nutrition and Combating Climate Change

The article “Is it a Case of 'Meat-versus-Planet'? Lessons for the Global South” by Aravindhan Nagarajan (9 July) provides important arguments and perspectives to cut through the noise and rhetoric surrounding animal-based foods and global warming.

This response is crafted with two main intents. I would like to highlight, first, that lost in the rhetoric about the emissions by livestock are scientific findings on the errors in the estimation approach used to determine the global warming potential of various greenhouse gases (GHGs). Understanding these findings will lead to a more accurate understanding of the impact of animal-based foods. Second, I would like to emphasise the need to examine this issue in a given socio-ecological context (as Nagarajan has done) by providing some ecological and livelihoods-related perspective.

Chemistry and the lifetime of greenhouse gases

One of the requirements of the Paris Agreement on climate change in 2015 was for countries to carry out a periodic assessment to track their progress in reducing carbon emissions. This was to meet the long-term temperature goal agreed upon under the agreement. An important element of this assessment is the use of a metric called global warming potential (GWP) of various GHGs.

Scientists from the Oxford Martin School’s programme on climate pollutants at the University of Oxford have pointed out a key problem in how GWP was being used. All GHGs (carbon dioxide, nitrous oxide, methane etc.) are presented as tonnes of carbon dioxide equivalent (“CO2-equivalent”) without considering that some gases like methane are short-lived climate pollutants, while others such as carbon dioxide live for a long time in the atmosphere. The warming potential of individual GHGs are therefore different.

Methane and carbon dioxide are not really equivalent in their global warming potential.

The Oxford researchers point out that by modifying the use of GWP based on individual GHG lifetimes, the real impact of “an emission pathway on global temperature” can be assessed more easily. Such an assessment will impact how a country's progress towards reaching its target is monitored. This will have implications for planning and allocation of resources to mitigate the impacts.

Let us take the case of methane, which is a GHG. The emissions of methane are multiplied by its GWP over 100 years (GWP100) and presented as CO2 equivalent. The value of GWP100 for methane is 28, which means that it has a global warming potential that is 28 times greater than that of carbon dioxide, i.e., one tonne of methane is equated to 28 tonnes of CO2 equivalent. However, what this does not say is that one tonne of methane has a high global warming influence only immediately after it is emitted. Methane has a half-life, the time required for its quantity to reduce to half of the initial value, of 10 years, which means its levels in the atmosphere will come down significantly in 10 years. This also means that in 100 years that methane will be almost completely destroyed.

Compare this with carbon dioxide. The same amount of carbon dioxide released into the atmosphere has a much longer half-life, possibly hundreds of years. It will therefore stay and continue to cause warming with the same potential as it did when it was released. Clearly, methane and carbon dioxide are not really equivalent in their GWP. The scientists have recommended a modified method called GWP* that takes into account these differences.

Estimates of GWP100 can therefore misinterpret the impacts of methane when used to compare differential mitigation strategies to reduce GHGs. The reduction targets for short-lived climate pollutants like methane should really have a different time schedule compared to long-lived ones like CO2. The implications of making an erroneous comparison between different GHGs need to be considered in the context of (i) the agribusiness and Big Tech push away from animal-based foods, (ii) the political context in India and the active promotion of vegetarianism in mid-day meals, and, most importantly, (iii) what it means for small and marginal farmers, livestock farmers in India and the sovereignty of our food systems.

Ecological and livelihoods-related perspectives

Livestock, grasslands, and grazing lands are inextricably linked in the cycling of carbon in the environment. This is central to our understanding of global warming and climate change.

Grasslands play an important role in carbon sequestration by serving as sinks of carbon. Grasses are perennial and have root systems that extend several metres below the surface. As a result, they are storehouses of large volumes of carbon in the ground. Studies in India and elsewhere have shown that grasslands are a large terrestrial carbon sink, with some reporting that in some arid and semi-arid regions, they can be larger sinks than forests. Often, grasslands where livestock graze and browse are marginal lands and therefore unsuitable for growing crops. These marginal lands are fertilised by animal manure. Such an ecosystem is at the centre of the dominant form of livestock rearing in India and several other countries in Asia and Africa. Unlike land that is cleared primarily to cultivate animal fodder or cultivate crops, these grasslands are not tilled and therefore they hold the soil carbon for a long time. This can be sustained with well-managed grazing practices.

Milk, meat, and eggs meet protein requirements that are often not met by plant-based proteins such as pulses, due to challenges of availability and accessibility.

Ruminant livestock (cattle, sheep, goat) provide several ecosystem services: they are efficient at “upcycling plants and crop waste” in addition to grazing on marginal lands. In the process, as Nagarajan points out, they convert these resources into nutritious and protein-rich food that is an essential source of protein for a large section of India's marginalised population. Milk, meat, and eggs meet protein requirements that are often not met by plant-based proteins such as pulses, due to challenges of availability and accessibility. The National Institute of Nutrition that provides dietary recommendations and guidelines advocates consumption of animal-based proteins together with pulses and legumes to address the malnutrition crisis in India. The 2010 guidelines state: “Animal proteins are of high quality as they provide all the essential amino acids in right proportions, while plant or vegetable proteins are not of the same quality because of their low content of some of the essential amino acids.”

In an increasingly climate unpredictable and uncertain environment, livestock rearing constitutes an important mechanism for coping with the risks of crop failure, both in terms of income and employment. Based on a comparative study of global livestock systems across 28 regions and eight livestock production systems, some researchers (Narain 2018, Herrero et al 2013) argue that what distinguishes dietary choice of animal products in India, more so meat consumption, is the mode of production and the amount consumed. This differentiation is critical in discussions around vegetarianism, meat consumption, dietary choice, ethics, and climate change in the Indian context since “livestock is the most important economic security of farmers in our world” and it is “their real insurance system, not the banks” (Herrero et al, 2013).

In an increasingly climate unpredictable and uncertain environment, livestock rearing constitutes an important mechanism for coping with the risks of crop failure.

Mixed crop-livestock systems that dominate food production systems in India, particularly in the rain-fed areas, are estimated to produce 40% of the foodgrains in the country (44% of rice, 87% of coarse cereals (sorghum, pearl millet and maize), 85% of legumes, 72% of oilseeds, and 90% of minor millets). These systems also support two-thirds of the livestock population (Rao 2015). Studies from the perspective of food security, livelihoods, and climate change mitigation clearly show the critical role of livestock-crop systems in carbon sequestration and therefore their role in building socio-ecological resilience (Thornton et al 2018).

Livestock are an integral part of the agricultural cycle in India. They are a source of manure and their dung and urine are used to improve soil fertility and in production of bio-fertilisers and bio-pesticides. This is increasingly acquiring significance given the demand for safe and non-toxic foods as well as reduction of fossil fuels in food production (Arneth 2019). Dairying and supply of manure are important sources of income and livelihood for small and marginal farmers, while rearing sheep and goat support resource poor, landless and women farmers in semi-arid and marginalised eco-regions. As emphasised in the Economic Survey of 2018-19, there are several factors that make goat and sheep rearing critical for survival of small and marginal communities in India. These are the high survival rates under drought conditions of goat and sheep, water efficiency of goats, and their ability to efficiently survive on available vegetation in adverse environments.


The implications of the above discussion need to be considered in the context of the future of our food system and the health of all life forms. The transformation of the industrial food system has been recognised as an imperative and is on the agenda of the UN Food Systems Summit 2021. However it is the nature of the transformation that is being heavily contested by social movements and farmers' groups, and needs to be examined critically by all of us as consumers.

There is mounting scientific evidence on the contribution of agriculture and food systems to global warming, particularly industrial meat and dairy systems. Farmers' movements and other social movements have demonstrated that the only way forward to mitigate global warming, address poverty, hunger and malnutrition, and build socio-ecological resilience is through food sovereignty that is based on agro-ecological practices and diversified local food systemsthe peasants' food web. This is a complete antithesis to agribusiness-controlled industrial food systems. The “plant forward” model allows agribusiness to continue to produce crops such as corn and soy (used today for animal feed) and "repurpose" them to produce processed plant-based alternatives to meat. In addition, lab cultured meat alternatives through cell lines derived from animals are also being offered as ethical alternatives to rearing animals purely for meat and dairy. Once again, like the Green Revolution, this is a technological response to a crisis rather than addressing deep-seated structural issues.

The “plant forward” model allows agribusiness to continue to produce crops such as corn and soy (used today for animal feed) and 'repurpose' them to produce processed plant-based alternatives to meat.

Globally, including in India and China, industrial agriculture is increasingly being controlled by large tech companies. The services they provide, range from building farmer databases including digitising land records (like Agristack being built by Microsoft in India) to precision and high tech solutions for both research and development as well as scale up. They are also integrated into the food system through online retail. The data generated from all nodes of industrial agriculture are then made available to large farmers (like data on soil quality, water requirements, and disease resistance) who can afford to purchase this data.

In India, the absence of data privacy legislation has also given rise to concerns of data privacy, farmer profiling and further corporatisation of agriculture. All this further marginalises the livelihoods, land and food security of small farmers and a large proportion of the population, in India and globally.

A point worth noting here is that some of the Big Tech players (including Bill Gates and Jeff Bezos) are among the largest agricultural landowners in the US. Land is central to food systems particularly for small and marginal farmers who build the peasants' food web, and anyone who controls land, controls the future of our food.

Why are agribusiness, large foundations such as Gates and Rockefeller, and Big Tech spearheading a push towards a transformation built on plant-based alternatives to animal-based foods? Why are they supporting a uniform “plant forward” planetary healthy diet proposed by the EAT-Lancet Commission? A recent study has shown that this diet is not affordable for “much of the world's low-income population.” Why is this diet from the EAT-Lancet Commission yet being promoted as a universal and uniform response to global warming? A detailed and exhaustive treatment of these questions is provided by Frederic Leroy and an interdisciplinary consortium of over 40 scientists.

-- Radha Gopalan



Arneth, A, et al. 2019. Climate Change and Land, An IPCC Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems. Doi: 10.4337/9781784710644.

Herrero, M. et al. 2013. “The roles of livestock in developing countries.” Animal, 7 (SUPPL1): 3–18.

Narain, S. 2018. “Why I would not advocate vegetarianism.” Down to Earth

Rao, C. S. et al. 2015. “Potential and challenges of rainfed farming in India”, Advances in Agronomy, 133:113–181. February 2015.

Thornton, P. K. et al. 2018. “A qualitative evaluation of CSA options in mixed crop-livestock systems in developing countries." In Climate Smart Agriculture, Natural Resource Management and Policy, edited by L. Lipper et al, 385–423.

Commentator name
Radha Gopalan