We’ve all heard about how cows and other grass-eating cattle release methane, a powerful greenhouse gas (GHG), when they belch and fart. The United Nations has suggested in the past that the environmental impact of cattle might be even more damaging than the emissions of cars and trucks combined. Now, a new study by the Food and Health Organization (FAO) says that greenhouse gas emissions by the livestock sector could be cut by as much as 30 percent if farmers adopt better techniques within existing production systems.

Titled, Tackling climate change through livestock: A global assessment of emissions and mitigation opportunities, the new study says emissions linked to livestock supply chains add up to 7.1 gigatonnes of carbon dioxide equivalent (CO2-eq) per year – or 14.5 percent of all human-caused GHG releases.

That’s less than the 18 percent that was cited by the FAO in a widely-quoted study in 2006 (Livestock’s Long Shadow) on emissions linked to global meat production. The FAO says the new figure is based on a new revised modelling framework and updated data.

The latest report pinpoints the main sources of emissions at different stages of various livestock supply chains – food production and processing (45 percent of the total), outputs of greenhouse gases during digestion by cows (39 percent) and manure decomposition (10 percent).

So, how can livestock production – a wide-ranging,  globe-spanning activity which varies greatly from country to country – lower its emissions? The FAO says it will require a mix of policies, incentives, and on-the-ground work.

The FAO study however says there is no need to shift from small-scale and backyard to industrial livestock farming. It says farmers need to more widely adopt best practices and technologies in feeding, health, husbandry and manure monitoring as well as make greater use of underused technologies such as biogas generators and energy saving devices.

“These efficiency gains can be achieved by improving practices, and don’t necessitate changing production systems,” Ren Wang, FAO assistant director general for agriculture and consumer protection, says. “But we need political will, better policies and most importantly, joint action.”