What is known about dairy cows emissions of greenhouse gases?
“The livestock sector emerges as one of the top two or three most significant contributors to the most serious environmental problems, at every scale from local to global… With rising temperatures, rising sea levels, melting ice caps and glaciers, shifting ocean currents and weather patterns, climate change is the most serious challenge facing the human race. The livestock sector is a major player, responsible for 18 percent of greenhouse gas emissions measured in CO2 equivalent. This is a higher share than transport… The sector emits 37 percent of anthropogenic methane (with 23 times the global warming potential (GWP) of CO2) most of that from enteric fermentation by ruminants [such as dairy cows]. It emits 65 percent of anthropogenic nitrous oxide (with 296 times the GWP of CO2 ) the great majority from manure…In the United States methane from enteric fermentation totaled 5.5 million tones in 2002…overwhelmingly originating from beef and dairy cattle. This was 71 percent of all agric
