Agriculture, particularly meat production, is being intensely scrutinized over its environmental impacts due to concerns with climate change and carbon emissions. For example, frequent calls have been made for the elimination of meat from diets as a means to address climate change. The increased attention got Jayson Lusk, an agricultural economist with Purdue University, to thinking about the shift in meat consumption which has already occurred over time, from beef to chicken, and what the environmental impacts might be.
Figure 1 shows the per-capita consumption of beef and chicken since 1970. The trends between the two protein sources are easily discernible. Per-capita consumption of chicken has increased while beef has declined. Lusk calculates the per-capita consumption of beef declined 34 percent since 1970, while the per-capita consumption of chicken increased 123 percent.
Figure 1. Per-Capita Consumption of Beef & Chicken
Studies have shown that chicken and beef emit different amounts of CO2 for each kg of meat produced. Lusk notes a United Nations Food and Agricultural Organization study indicated 5.4 kg of CO2 is produced for each kg of chicken. A study by the USDA, the National Cattlemen’s Beef Association, and the University of Arkansas indicated 22 kg of CO2 is emitted for each kg of beef produced. The CO2 emissions differences mean changes in consumer consumption of beef and chicken over the past 50 years have impacted overall carbon emissions.
Lusk concludes the carbon impacts of the switch from beef to chicken has been a net carbon win. Lusk writes, “the average American is emitting 87.3 more kg CO2 from extra chicken consumption but has cut 705 kg CO2 from less beef consumption since the 1970s. Looks like a net carbon win. And one that isn’t even close.” Lusk also examines the changes taking into consideration population growth, “we are, in aggregate, emitting 44.7 million metric tons (MMT) more CO2 from extra chickens but 67.1 less MMT CO2 from fewer cattle. Thus, on net, we are emitting 22.4 MMT fewer CO2 equivalent gasses from our aggregate beef and chicken consumption today than in the 1970s.”
As the world looks to tackle climate change, it’s important to recognize changes in emissions already occurring organically through consumer changes in preferences. Lusk’s work suggest shifts in consumers’ meat consumption is already resulting in net carbon reductions. Yet, just as likely , there are emission increases resulting from other changes in consumer preference. It’s all part of a dynamic system.