Livestock husbandry is a primary anthropogenic source of global greenhouse gas (GHG) emissions. The Qinghai-Tibetan Plateau (QTP), an important geography for animal husbandry in China, and is therefore a significant contributor to the global GHG budget. Therefore, this study employs the life cycle assessment method to comprehensively assess the effect of yak grazing on GHG balance and enhance our understanding and monitoring of GHG budgeting in the alpine ecosystem. The results show that yak grazing alters the GHG balance of alpine meadow ecosystems from sink to source (Critical value = 1.3 yak/ha). Sequestration of CO2 in soil organic matter is the most significant contributor to the GHG balance in both grazed and ungrazed grassland. In grazed grassland, enteric fermentation and livestock manure and its management (dung and urine patches, manure heaps, night pens, and dry stored manure combustion) are important contributors to the total GHG balance, where implementing mitigation practices that target reductions of enteric fermentation and improve manure management can help to alleviate these emissions. Due to the unique geographical and biophysical environment of the QTP, solar and wind energy are viable emission-free alternatives to dry manure consumption, and livestock enclosure has the potential to restore soil organic carbon stocks by increasing sequestration of atmospheric CO2. In conclusion, our findings suggest that successful implementation of targeted emission reduction measures is conducive to the sustainable development of animal husbandry, while also maintaining a balance with ecosystem functions under the multifaceted ecological landscape of QTP.