Animal production is a major contributor to greenhouse gas emissions, accounting for 12% of global emissions and about 40% of agri-food system emissions, mainly due to methane. It also faces criticism for its roles in deforestation, land competition, pollution, and health concerns, sparking debates and calls for reduced meat consumption, especially in the Global North. However, livestock systems vary widely worldwide, with many in the Global South playing vital social, economic, and ecological roles, such as supporting livelihoods, maintaining soil fertility, and preserving ecosystems. Pastoral and mixed farming systems contribute to biodiversity and carbon storage, highlighting the complexity of livestock’s impacts. This chapter reviews livestock’s climate impact globally and addresses controversies surrounding its environmental, social, and economic functions.