According the EPA, all livestock only represents 3.9% of the US GHG emissions, which is far lower than the 18% - 51% range many plant-based advocates report. The largest source of GHG emissions in the US comes from energy and transportation. Within the livestock category, beef represents 2% of total US GHG emissions. Regardless of the statistic, we again are talking about studying a dysfunctional system (which the numbers aren’t so bad when considering that). Within a healthy ecosystem with healthy soils, there is a bacteria present called methanatrophic bacteria that is responsible for pulling methane from the air and putting it in the soil.