Look at the big picture to reduce greenhouse gases
Around 1.6-2.7 billion tonnes of greenhouse gases each year, mostly methane, are produced from livestock digestion. Another 1.3-2.0 billion tonnes of nitrous oxide come from producing feed for livestock. And the final 1.6 billion tonnes comes from land use changes, such as clearing for animal pastures.
Emissions from livestock production vary across the globe. The developing world accounts for 70% of emissions, mainly because of the large numbers of animals used for a variety of purposes beyond production of meat, milk and eggs.
The emissions intensity of producing livestock products (the amount of greenhouse gas that goes into producing a kilogram of protein) also differs significantly between regions. The developed world has lower emission intensities than the developing world due to the use of better feeds and management practices.
It seems likely that emissions from livestock could be reduced by around 2.4 billion tonnes of greenhouse gases each year through technology and management.
Achieving these savings will be dependent on improvements in feeding practices (better pastures, new types of food, more grains and others), improved ways of handling manure, and improved genetics and animal management. Many of these strategies are based on sustainable intensification: producing more livestock protein with fewer resources; and storing carbon in the land.
Policy changes will also be important. Adoption of many practices that reduce gross greenhouse gas emissions has been low (10-30% of producers) due to poor incentives. Unfavourable credit conditions, lack of markets, and/or systems for rewarding environmental performance are all hurdles.
The elephant in the room is whether we should be looking to transition away from eating meat. We found that, in theory, this practice could mitigate up 5-6 billion tonnes of greenhouse gas emissions in the most extreme scenarios.
But as with many interconnected systems there is rarely an easy answer. In the developing world for instance, where lack of some nutrients and too many of others can occur at the same time, the problem is more complex. The question becomes about who keeps on eating and who should reduce consumption, and which products and where.
These issues are highly localised and therefore require local policy responses and action. With such an interconnected sector contributing 40-50% of agricultural GDP and to significant employment, poorly planned transitions in the global food system could have serious negative consequences in terms of the Sustainable Development Goals.
The full article can be read on https://theconversation.com/to-reduce-greenhouse-gases-from-cows-and-sheep-we-need-to-look-at-the-big-picture-56509