In North America, we regularly read about the problems associated with factory farms and the benefits of returning to small-scale agricultural production. However, small farms may not always be better for the environment, depending on geography and other factors.
New research published yesterday in Proceedings of the National Academy of Sciences aims to give a more nuanced understanding of how livestock impacts the environment from region to region. The researchers looked at the efficiency of feed to protein conversion and the production of greenhouse gases, then analyzed these impacts according to animal and farm type. The authors hope this dataset can provide the basis for further analysis.
The research finds that it's hard to make sweeping conclusions about the impact animals have on the ecosystem:
"The sector has many dualities, and the roles played by livestock change depending on location and circumstances."
For example, eating large quantities of animal products in the developed world can tax our natural resources and lead to poor health. "But in the developing world, you still have a lot of people who are undernourished," said lead author Mario Herrero, a scientist at Australia's Commonwealth Scientific and Industrial Research Organization. "We think you can't just throw out a blanket recommendation suggesting to decrease livestock product consumption."
Animal waste contributes to greenhouse gases, but the quality of feed can impact how much. The data show a correlation between better feed in developed nations and lower emissions, regardless of the type of farm. "Although no obvious trend by production system is discernible, all systems in the developed world have lower emission intensities than those in the developing regions," the authors write.
Sub-Saharan Africa, Latin America and South Asia have the highest total emissions from livestock. These are places where most livestock is raised on small farms. Emissions could be reduced by improving the quality of feed, which would also lead to more efficient conversion to meat. Globally, cattle contribute the highest percentage of greenhouse gases from livestock, accounting for 77 percent.
However, Herrero points out that the right market conditions need to exists for farmers to be motivated to improve their feed. "A key part of the sustainability education is really that we need to invest in market development and improved value chains," he said.
For people in developed countries, reducing consumption is the more sustainable choice. Herrero doesn't want to prescribe how much people living in developed countries should reduce their consumption of animal products. But he does encourage people who have the choice to eat less meat, dairy and eggs to do so. "We have options," he said. "Why not reduce consumption? We need to exercise that choice a little bit more actively."