Livestock’s Lure and Liabilities

The human appetite for the food products
from livestock meat and milk is seemingly insatiable. Worldwide, four-fifths of all agricultural land is dedicated to raising livestock. And with
the growth in population and wealth in developing countries, that appetite is
only getting bigger. By 2050, the demand for meat and milk is expected to
increase by eighty percent. However, there there is growing concern about how to
accommodate this increase in demand with a low environmental footprint and
without eroding the economic, social and cultural benefits that livestock provide.
And herein lie many challenges. One is that meat and milk supply only 15% of
the total energy and 30% of the protein in the average global human diet, despite
taking up eighty percent of all agricultural land for their production.
On top of that, livestock already emit large quantities of greenhouse gases and
use 25 to 32 percent of global freshwater. A third batch of problems is
created by climate change itself. Heat stress and water scarcity affect animals
and production of their feed and alter the prevalence and intensity of disease. Over the past ten years, a great deal has
been learned about the environmental impacts of livestock. We now have an idea of what might constitute a more sustainable system, but we don’t quite
know how to get there. What’s urgently needed is research to develop efficient
and culturally equitable pathways for transitioning to more sustainable
livestock systems. Let’s look at the emissions issue in more detail. The
seventeen billion food-producing animals across the globe collectively emit between 8 and 18
percent of greenhouse gases. Most of this is methane generated in the digestive
tracts of ruminants – animals such as cattle, sheep and goats. Another portion
is emitted as carbon dioxide as a result of changes made to soil and plants to
accommodate livestock. So how might these emissions be managed? Consider global livestock farming as a
factory. Some livestock systems utilize resources much more efficiently than
others. Specifically, pork and chicken show better environmental performance
per unit of product than dairy or beef cattle. To output quality products with
low emissions of harmful gases, you need to manage the input. For farmers, that
means providing animals, especially cattle, with feed containing additives
that curb the formation of methane or using high quality feed that is packed
with energy and is easier to digest. Another major input that can be
controlled is the land used for grazing. Because plants and soil are enormous
sinks for carbon dioxide, oversowing grasslands with crops like legumes and
avoiding massive changes in land cover promotes the storage of carbon dioxide,
reducing the effects on the environment. Changing consumer behavior is another
goal. Reducing the consumption of animal products would free up space for forests
and grasslands that capture carbon dioxide from the atmosphere, as well as
promote a healthier diet. However, studies to date have been unable to fully
capture the indirect effects that shifts in consumption habits could have on land
use, agricultural productivity and even household budgets. The design and adoption of practical sustainable solutions remain a considerable challenge – a global
one. Taking on this challenge requires incentives and other policies for
effecting changes in how livestock are raised and
how their products are consumed – all to ensure that livestock contribute to the
sustainable and nutritious diets of different age groups of the human
population. Most importantly, these efforts must be regionally and
culturally sensitive. Now is the time to move from knowledge to action – from
assessing the world’s needs to figuring out how to satisfy them.