Beef production is a significant contributor to global climate change. The source of greenhouse gas emissions is primarily due to inputs into the system such as fertilizer and feed. Estimates of greenhouse gas emissions from beef production are highly variable. Globally, livestock contribute 14% to 18% of total greenhouse gas emissions. Beef production alone accounts for a smaller percentage (6%). In the U.S., beef is an even smaller proportion – only 2%.
So why the discrepancy? Greenhouse gas emissions are highly dependent upon the production system. More intensive systems utilizing highly nutritious feeds, high quality animal genetics, and high levels of management such as the U.S. system produce more beef for each unit of input, which drives down the greenhouse gas intensity. The greenhouse gas intensity is the amount of greenhouse gas emissions per unit of output, in this case carcass weight.
Because of the investment in nutritional quality of feed, animal genetics and management practices, the U.S. system has the lowest greenhouse gas intensity of any major beef producing country (Figure 1). The U.S. produces 18% of the world’s beef and only 8% of the world’s greenhouse gas emissions from beef production. In comparison, Brazil produces 14% of the world’s beef and 19% of the world’s greenhouse gas emissions from beef production. The U.S. system has a ratio of 2.2:1 compared with Brazil’s ratio of 0.75:1 of contribution to beef production relative to contribution to beef greenhouse gas emissions. The U.S. production system has the highest ratio of any of the top 10 beef producing countries with Germany having the next closest at 2.0:1.
Comparisons among greenhouse gas emission intensities of countries (i.e., production systems) indicates that intensifying the system through improving efficiency should be the goal. A global effort to improve nutritional value of feed, increase cattle genetics for growth and yield, and increase producer education of optimum management practices will have the greatest benefit to sustainable beef production. If the other 9 of the top 10 beef producing countries developed beef production systems similar to the U.S., global greenhouse gas emissions from beef production would be reduced by 22%.