Forum: Climate, Ecological, and Social Costs of Livestock Grazing on Western Public Lands.

Grazing by domestic livestock is the most widespread use of public lands in the American West (USA) and their effects on climate change and ways to mitigate those effects are of interest to land managers, policy makers, and the broader public. Kauffman et al. (2022a) provided a meta-analysis of the ecosystem impacts, greenhouse gas (GHG) emissions, and social costs of carbon (SCC) associated with livestock grazing on public lands in the western USA.

Livestock Use on Public Lands in the Western USA Exacerbates Climate Change: Implications for Climate Change Mitigation and Adaptation.

Public lands of the USA can play an important role in addressing the climate crisis. About 85% of public lands in the western USA are grazed by domestic livestock, and they influence climate change in three profound ways: (1) they are significant sources of greenhouse gases through enteric fermentation and manure deposition; (2) they defoliate native plants, trample vegetation and soils, and accelerate the spread of exotic species resulting in a shift in landscape function from carbon sinks to sources of greenhouse gases; and (3) they exacerbate the effects of climate change on ecosystems by creating warmer and drier conditions. On public lands one cow-calf pair grazing for one month (an "animal unit month" or "AUM") produces 875 kg COe through enteric fermentation and manure deposition with a social carbon cost of nearly $36 per AUM.