From Beef To Beans: Mitigating Climate Change
To curb rising temperatures, most countries have focused on reducing carbon dioxide (CO2) as a way of reducing greenhouse gas (GHG) emissions. However, methane (CH4) and nitrous oxide (N2O) are also significant GHG contributors to climate change. Livestock farming is the primary producer of both of these GHGs, and is responsible for about 15% of all GHG emissions related to human activity. CH4’s short atmospheric lifespan and the mean global warming potential of both CH4 and N2O over the next century make reducing these GHGs imperative to the short-term.
Although up to half of the possible mitigation of GHGs in the agriculture, forestry, and land-use sectors could be accomplished by cutting back on livestock, the global demand for meat makes that impossible. Due to policies and cost surrounding the livestock industry, scientists estimate that only 10% of the potential livestock-related GHG reduction is possible. Without human dietary change, the livestock industry could account for half of our emissions budget imposed by the Paris Agreement by 2050, and all of it by 2070.
This study compared beans and beef in terms of greenhouse gas emissions and nutritional value. It analyzes the direct GHG emissions created by consuming beans as opposed to beef, and does not consider the emissions that would result from the real-life implication of converting pasture for livestock into cropland for beans. According to the researchers, it is the first study to analyze dietary changes as a way of meeting GHG emission targets.
At the time of the study, the US President’s climate change plan required a 7% reduction in 2013-level GHG emissions by 2020. Since CO2 is the standard GHG emission target, the researchers converted total GHG emissions into their CO2 equivalent (denoted CO2e).
Beef emits 9-129 kg CO2e per kilogram produced, making it the most GHG-intensive food. By comparison, beans emit 1-2 kg CO2e per kilogram. For every 100 g of raw weight, beef provides 332 kcals and 14.4 g of protein whereas beans provide 341 kcals and 21.6 g protein. Beef had a higher moisture content (54%) than beans (11%), and was consumed at a much higher level.
The researchers concluded that replacing beef with beans in the United States could accomplish up to 75% of the total GHG reduction needed to meet 2020 goals, in addition to reducing up to 42% of U.S. cropland required for food production. On a global level, it could account for as much as 47% reduction in GHG emissions. The researchers acknowledged that since replacing beef for beans does cover 100% of US GHG emission targets, it would be best to combine dietary modification with other climate change mitigation efforts in the power and transportation industries.
On a nutritional level, beans appear to be a good and healthy replacement for beef. The researchers suggested consuming 0.8 of a cup of black beans to replace the average calories consumed from beef. They noted that making such a switch could have other benefits as well, such as increased fiber intake and a reduced risk of heart disease, diabetes, and certain cancers related to meat.
The researchers acknowledged that while not everyone is willing to switch to a meat-free diet, people who are aware of the climate impacts of meat are more likely to reduce their meat consumption. Other research suggests that the health benefits of plant-based diets are strong motivators for some people to cut out meat. Beef-like replacement products are likely to increase consumer interest in meat as they become more common in the market, and research suggests that consumer acceptance, palatability, and availability of these products is already on the rise.