Response of grassland greenhouse gas emissions to different human disturbances – A global Meta-analysis - Yong Cao; Zemin Ai; Xiaohu Dang; Huan Liu; Qingqing Li; Mengjia Hou; Yuyan Yao; Yi Deng; Lie Xiao; Shuaimeng Zhu (Agriculture, Ecosystems & Environment, 2025)