“The challenge ahead is unequivocal,” says Mario Herroro, senior agro-ecological systems analyst with the International Livestock Research Institute. “We need to feed 9 billion to 10 billion people in the future at a lower economic cost, but also in a socially and economically acceptable way.”
As food systems continually evolve, he points out, the research agenda must also adapt to satisfy societal and economic interests. This requires taking a look at the global picture of livestock production and related greenhouse gas (GHG) emissions, then identifying potential areas of mitigation.
Doing so presents a challenge, nonetheless, as livestock systems of all sizes, scales and technological levels are found around the world. In fact, Herroro says, livestock consume one-third of the world’s freshwater supply and occupy the same portion of the ice-free surfaces. Over 30 percent of available croplands are also necessary to produce the grains for livestock production. The world’s estimated 17 billion domestic animals contribute 14-18 percent of GHGs.
Though livestock production requires a significant portion of global resources, its economic and nutritional benefits cannot be disputed. The estimated value of livestock, excluding infrastructure that supports related industries, is at least $1.4 trillion. Its contribution to the agricultural gross domestic product (GDP) is as much as 40 percent, providing more consistent income than crop production and serving as a risk management tool, particularly for the poor.
“At least 600 million of the world’s poor depend on livestock,” Herroro says, referring to the economic benefit.
From a nutritional perspective, 17 percent of the global kilocalorie consumption and 33 percent of the protein consumption is from livestock. The highest rates of increases in consumption of livestock products are in the developing countries of the world.
“The livestock revolution,” as he refers to it. “As people get richer and urbanized, they consume more meat.”
The demand for chicken, pork, milk and other animal proteins creates enormous pressure on the world’s resources, Herroro states. The world will require 1 billion tons of additional cereal grains in order to meet both food and feed demands by 2050.
“Livestock will consume almost as much grains as needed for human consumption,” he adds, estimating that monogastric livestock will require 430 million tons more of grains, while meeting the human demand will require 458 million tons. An additional 160 million tons are expected to be needed for biofuel production.
As agriculture grows in response to increased demands for food, feed and other resources, emissions from the sector are projected to grow as well. As quantified in the paper Livestock’s Long Shadow: Environmental Issues and Options, agricultural GHG emissions primarily result from feed production, livestock rearing and post-harvest (slaughter house and processing). This includes the gammet of operations related to production, such as the fabrication and application of chemical fertilizers, on-farm fossil fuel use, fermentation, manure and transportation.
Based on the points of emissions and the growing demand for animal protein, Herroro recognizes that opportunity may lie in improving the efficiency of livestock production, especially in developing areas, which could reduce GHGs.
“The developing world has enormous livestock mitigation potential, and this is largely associated with livestock practices,” he states.
While improving management strategies for cropland, grazing land and organic soils could reduce carbon dioxide and nitrous oxide emissions, changes to livestock feeding practices and genetic advancements have the potential to be effective strategies in decreasing methane. For example, certain feed additives can reduce methane production during rumination. Herroro also says that if crops yields are improved, livestock production could increase at a faster pace to meet growing demands.
Another mitigation theory Herroro brings up is managing the demand for animal products by reducing consumption. Consuming less or different types of meat could lower GHGs. However, this concept could have negative socio-economic impacts, particularly on the poor.
Changing not only quantities of animal products consumes, but the type of animal could impact emissions as well. He notes very low emission intensities among poultry and pork compared to beef production, which requires greater GHG intensity per kilogram of animal protein produced.
Feed and land use, he adds, will be the key drivers for determining the efficiency of the livestock sector.
“The better we feed cows, the less methane per kilogram of milk they produce,” he points out. However, this can be counterproductive because as milk production increases, feed intake increases as well, and, thus, methane. Producing more milk with less animals is the way to reduce overall emissions. “The key here is less – but better-fed – animals,” according to Herroro.
He cites a study that estimated the potential for reducing methane from livestock in Sub-Saharan Africa and Southeast Asia. Intensifying the diet for cattle by introducing a stover with higher digestibility could mean significant mitigation - more than a 60 percent reduction in methane produced and number of cattle needed to satisfy the projected demand for 2030. Even if the intensified diet were adopted at a rate of 23 percent, methane would be reduced by 14 percent. Acceptance and adoption of such practices is critical.
Another area that could be targeted for GHG mitigation is carbon sequestration, particularly in the vast rangelands of Africa. This could be an important income diversification source for landowners, but the challenges lie in measuring and monitoring stocks and establishing payment schemes.
Though each of these mitigation strategies have the potential to reduce GHGs, Herroro emphasizes that trade-off’s must be considered. “Mitigation in livestock systems requires the fundamental recognition that societal benefits need to be met at the same time as the environmental ones.”