A new study in India has found that greenhouse gas emissions by cattle are significant but much lower than earlier estimates made by some scientists in developed countries

(Image by Kavita Kapoor)

Cattle contribute significantly to greenhouse gas (GHG) emissions, according to a study on livestock in 60 smallholder farms in Gujarat’s Anand district, India’s milk capital. The emissions, however, are lower than earlier estimates by multilateral agencies, vindicating a longstanding contention of Indian scientists.

Cows and bulls generated three-quarters of the methane, 11% of the carbon dioxide (CO2) and 13.6% of the total GHG emissions from these farms, researchers found. According to the study by the National Dairy Development Board (NDDB) and others, emissions from buffaloes have an even higher percentage of methane, 80.5%.

The location of the study is important because Anand is the headquarters of the Gujarat Co-operative Milk Marketing Federation Ltd, which is known by its ubiquitous Amul dairy products brand. The federation ignited the white revolution in the 1970s. India today is the world’s largest producer of milk, accounting for 14% of total global production.

As a greenhouse gas, methane is 23 times more harmful than CO₂. In the farms of developed economies, a cow can release up to 100 kg of methane a year, equivalent to 2,300 kg of CO₂.

The local study, led by M.R. Garg of the Animal Nutrition Group at NDDB in Vadodara, assessed the farms by their lifecycle emissions from cradle to farm gate. NDDB has set up a field laboratory to measure methane emissions in dairy animals. Field trials are conducted with different categories of animals to measure methane emissions before and after feeding of a balanced ration to generate baseline data.

Other developing countries such as China, Pakistan and Brazil, which rank third to fifth among the largest milk producers, with the US at second position, also lend themselves to life-cycle assessments because of the higher proportion of small farms in their dairy industries.

The three researchers, who include H.P.S. Makkar from the Food & Agricultural Organisation (FAO) in Rome, also calculated the carbon footprint in terms of kilogrammes of CO2-equivalent. The results were released in the Animal Production Science journal last month.

Overall, the carbon footprint was 2.2 kg of CO₂-equivalent per kg of milk, which declined to 1.7 kg when milk, manure, finance and insurance against crop failure were taken into account as economic benefits of the smallholder farms. This compares with 4 kg of CO2 in the US.

The Anand study says the carbon footprint it found “was lower by 65% and 22% for cow and buffalo milk, respectively, than were the estimates of FAO for southern Asia, and this was mainly attributed to difference in the sources of GHG emissions, manure management systems, feed digestibility and milk production data used by FAO.”

Experts are reluctant to extrapolate the estimates of the Anand study to the entire country. “The study based on 60 farmers in Anand may be difficult to extrapolate to India’s entire cattle population due to differences in breeds, feeding patterns, productivity, climate, etc. across the country,” said Rakesh Saxena of the Institute of Rural Management, Anand (IRMA).

“This micro study can be used to estimate the GHG emission from the cattle population in India. But that will have large uncertainty, mainly because of the livestock feed, breed and temperature in which they live are not same all over India,” concurred Neha Pahuja of The Energy & Resources Institute (TERI) in New Delhi.

NDDB officials aren’t allowed to offer comments to the media.

The total methane emissions from Indian livestock, which include fermentation in intestines and manure, was 11.75 million tonnes in 2003, according to a 2009 paper by Abha Chandra of the Indian Space Research Organization and others, which is taken to be authoritative.

Cows comprised 38% of livestock, followed by goats, buffalos and sheep. Intestinal fermentation accounted for 91% of methane emissions. Cows and buffalos contributed 60% of methane emissions, according to the 2009 paper.

The FAO says that since the 1970s, most of the growth in milk production has been in South Asia, which is the main driver of growth in the developing world.

Total emissions from global livestock, FAO says, are 7.1 gigatonnes of CO2 per year, representing 14.5% of all manmade GHG emissions. This corroborates FAO’s previous assessment, Livestock’s Long Shadow, published in 2006. Cattle (raised globally for both beef and milk, as well as for manure and draught power) are responsible for about 65% of the livestock sector’s emissions. In terms of activities, feed production and processing (including changes in land use) and intestinal fermentation from ruminants are the two main sources of emissions, representing 45% and 39% of the total.

Dairy industry experts contend that the FAO and other multilateral organizations based in the North tend to highlight the so-called weaknesses of developing countries in this sphere.

India’s emissions from cattle are not that high, they say. It has a large number of unproductive animals, but the sector has a lot of strength because the by-products of food crops provide valuable food to animals. This includes fodder, grain and oilseeds.

There are many cows in villages where 80% of the milk is directly consumed — not processed into other products like paneer — and is not pasteurized. This is a distinctive feature of South Asia.

The oblique criticism of experts in the North resonates with the disagreement between the Washington-based World Resources Institute (WRI) and the New Delhi-based think-tank, Centre for Science & Environment (CSE), in 1991 on the eve of the Rio de Janeiro Earth Summit.

The WRI published a report that showed India was the world’s fifth largest net GHG emitter when both carbon dioxide and methane were combined. Both cattle and rice cultivation generate methane.

“The methane issue raises further questions of justice and morality,” CSE said at that time. “Can we really equate the CO₂ contributions of gas-guzzling automobiles in Europe and North America or, for that matter, anywhere in the Third World with the methane emissions of draught cattle and rice fields of subsistence farmers in West Bengal or Thailand?”

“Do these people not have a right to live? But no effort has been made in WRI’s report to separate out the `survival emissions’ of the poor, from the `luxury emissions’ of the rich.” said the CSE paper titled Global warming in an unequal world: A case of environmental colonialism.

The WRI relied on a single paper by P.J. Crutzen — who later won a Nobel prize for chemistry for his work on the ozone layer — which estimated that each of the 1,300 million heads of cattle in 1988 emitted 45 kg of methane a year on average.

Cattle in industrial countries emitted 55 kg a year as against 35 kg in developing countries, according to Crutzen. This was because many heads of cattle in the latter are kept for draught purposes rather than milk or meat, he said.

The CSE critiqued that it wasn’t clear how Crutzen arrived at the conclusion that the total animal methane production was roughly the same in the North and South. The WRI estimated that 60% of such emissions were from the South.

The CSE contended that the discrepancy was due to different cattle population figures. The WRI used FAO data that estimated the total number as 1,300 million, where the South had roughly twice as many as the North — 860 million versus 404 million. However, Crutzen estimated that the population was equally divided between North and South.