Milk production is rooted in animal husbandry, and the rearing of cattle, buffalos, and goats is a major source of one extremely potent greenhouse gas, namely methane.
India today is undoubtedly a global giant in milk production. It is already the largest producer and is only going to grow further ahead of its competition in the coming years. However, this growth cannot and should not escape scrutiny from a climate change perspective. Milk production is rooted in animal husbandry, and the rearing of cattle, buffalos, and goats is a major source of one extremely potent greenhouse gas, namely methane.
It is estimated that about 20% of global warming since pre-industrial times can be attributed to this gas. India’s emissions of methane from livestock currently stand at about 13% of global emissions from livestock. As the average Indian starts getting richer, the demand for milk will go up. This will spur the demand for livestock and in turn, lead to greater amounts of methane emissions. In my joint work with Ridhima Gupta from South Asian University, published in the journal Climatic Change early last year, I examine this possibility.
The primary objective of our study is to quantify the impact of milk demand on methane emissions. We begin by estimating the future demand for milk in India using past data on consumption and expenditure from over eight hundred thousand households in six separate cross-sectional surveys of the National Sample Survey Organisation.
We convert the estimated milk demand into corresponding amounts of methane emitted, using per unit milk emission factors. Emission factors estimate the amount of methane released into the atmosphere for every litre of milk produced. This essentially gives us the trajectory of methane emissions due to milk in the future. Our results indicate that between 2012 and 2050 methane emissions from milk production in India will more than double from about 2.17 million tonnes to 4.5 million tonnes. This amounts to an annual growth rate of about 1.9% and it is much higher than other projections of emissions from livestock.
The emission factor that we use above is a key component of our study. Its value is contingent on the breed of the animal producing the milk. Our estimate of milk demand does not carry any information about the breed of the source animal. So in order to apply the correct emission factor we have to take into account the chance that the milk consumed by a particular household is being sourced from a particular breed of animal. We do this by using the district-level distribution of breeds from the Livestock Census of India. The bottom line is that our final estimate of methane emissions would vary significantly if the distribution of breeds of milk animals in the country were to change.
We consider three broad categories of milk-producing animals in India, indigenous cattle, crossbred cattle, and buffalo. Of these three, the emission factor (methane/unit milk) for the crossbred cattle is the best (lowest), followed by the buffalo and then indigenous cattle. This implies that if the proportion of crossbred animals in the Indian livestock were to rise the average emission factor for the country would improve and methane emission would be lesser. In fact, we show in our study than in the hypothetical scenario where our entire livestock consists only of crossbred animals, the estimated milk demand in 2050 can be serviced with just a 40% increase in emissions.
The demonstration of the power of adopting crossbred cattle in reducing greenhouse gas emissions is perhaps the most significant result of our study. Although crossbred cattle are widely known to have higher yields than Indian breeds, adoption of crossbreeding in India has been limited. The promotion of crossbreeding was one of the declared objectives of the famous Operation Flood, the large-scale government plan to enhance the production and marketing of milk in India. However, in spite of the best efforts of the government, this objective is still far from being complete.
This outcome is somewhat surprising. The adoption of crossbreeding seems to be a win-win all around. Not only will this help generate greater milk yields providing more income to dairy farmers, but it will also help reduce the carbon footprint of our milk industry. Given the potential for growth in this sector, the gains seem to be obvious. However, if farmers have not chosen this on their own, it implies the existence of hidden factors preventing this change. For example, farmers in India usually have a small operation and may lack the resources or the knowledge to shift to crossbred animals. From a policy perspective, we need to understand and address the factors that prevent the adoption of crossbreeds by our milk farmers. Otherwise, our milk-producing sector is in danger of making significant negative contributions to climate change and methane emission.
Amlan Das Gupta
Associate Professor, O.P. Jindal Global University, India.