Shift in the trend of browning in Southwestern Tibetan Plateau in the past two decades

•Unlike the persistent greening trend in the northeastern part, the southwestern part was browning in 2000s but turned to greening in 2010s.•Precipitation was the key factor controlling NDVI dynamics in both northeastern and southwestern Tibetan Plateau.•Changes in the strength of Indian monsoon might contribute to the shift trend of NDVI in the southwestern part.