Reducing climate impacts of beef production: A synthesis of life cycle assessments across management systems and global regions

Abstract

The global demand for beef is rapidly increasing (FAO, 2019), raising concern about climate change impacts (Clark et al., 2020; Leip et al., 2015; Springmann et al., 2018). Beef and dairy contribute over 70% of livestock greenhouse gas emissions (GHG), which collectively contribute ~6.3 Gt CO2‐eq/year (Gerber et al., 2013; Herrero et al., 2016) and account for 14%–18% of human GHG emissions (Friedlingstein et al., 2019; Gerber et al., 2013). The utility of beef GHG mitigation strategies, such as land‐based carbon (C) sequestration and increased production efficiency, are actively debated (Garnett et al., 2017). We compiled 292 local comparisons of “improved” versus “conventional” beef production systems across global regions, assessing net GHG emission data from Life Cycle Assessment (LCA) studies. Our results indicate that net beef GHG emissions could be reduced substantially via changes in management. Overall, a 46 % reduction in net GHG emissions per unit of beef was achieved at sites using carbon (C) sequestration management strategies on grazed lands, and an 8% reduction in net GHGs was achieved at sites using growth efficiency strategies. However, net‐zero emissions were only achieved in 2% of studies. Among regions, studies from Brazil had the greatest improvement, with management strategies for C sequestration and efficiency reducing beef GHG emissions by 57%. In the United States, C sequestration strategies reduced beef GHG emissions by over 100% (net‐zero emissions) in a few grazing systems, whereas efficiency strategies were not successful at reducing GHGs, possibly because of high baseline efficiency in the region. This meta‐analysis offers insight into pathways to substantially reduce beef production's global GHG emissions. Nonetheless, even if these improved land‐based and efficiency management strategies could be fully applied globally, the trajectory of growth in beef demand will likely more than offset GHG emissions reductions and lead to further warming unless there is also reduced beef consumption.

Roadmap for achieving net-zero emissions in global food systems by 2050

“…to improve e ciency and nature-based carbon sequestration (Cusack et al, 2021;Roe et al, 2021). Lowemission interventions could result in ~40-70% less GHG intensive production systems compared to today's average levels (Poore & Nemecek, 2018).…”

“…Even with higher e ciency, greater production needed to meet growing demand might increase net GHG emissions. This condition suggests that dietary changes, including a reduction in consumption of livestock products and replacement by plant-based foods, is also important to help transition to low-carbon and net-zero food systems (Cusack et al, 2021;Roe et al, 2019;. Furthermore, several technologies developed or under development might help further reduce emissions in the medium and long run, such as feed additives for livestock, novel perennials, soil additives, nanoproducts and intelligent food packaging (Herrero et al, 2020).…”

Grazers and fires. Their role in shaping the structure and functioning of the Río de la Plata Grasslands

“…The main determinant of the negative environmental impact of livestock production systems is the conversion of natural habitats (Griscom et al 2020;Cusack et al 2021). Preserving grasslands, savannas and woodlands would warrant lower GHG emissions and biodiversity preservation.…”

Rapid global phaseout of animal agriculture has the potential to stabilize greenhouse gas levels for 30 years and offset 68 percent of CO2 emissions this century

“…But even in the context of large-scale reduction in emissions from other sources, major cuts in food-linked emissions are likely necessary by 2075 to limit global warming to 1.5˚C [6]. While a reduction of food-linked emissions can likely be achieved by increasing agricultural efficiency, reducing food waste, limiting excess consumption, increasing yields, and reducing the emission intensity of livestock production [7][8][9][10][11][12], they are not anticipated to have the same impact as a global transition to a plant-rich diet [5,6].…”