Global degradation trends of grassland and their driving factors since 2000

Abstract

Grassland is the second largest terrestrial ecosystem and a fundamental land resource for human survival and development. Although grassland degradation is a recognized and crucial ecological problem, there is no consensus on the area, scope, and degree of its global degradation trends, making the implementation of Sustainable Development Goals (SDG) 15.3 for achieving a land degradation-neutral world uncertain. This study quantitatively explored global grassland degradation trends from 2000 to 2020 by coupling vegetation growth and its response to climate change. Furthermore, the driving factors behind these trends were analyzed, especially in hotspots. Results show that the improvement in global grassland has been remarkable since 2000, with a 1.92 times larger area than degrading grassland, amounting to 372.47 × 104 and 193.57 × 104 km2, respectively. Africa and Asia lead in global grassland degradation and improvement, respectively. Globally, the combined effects of climate change and human activities are the main driving factors for grassland degradation and improvement, accounting for 84.72 and 87.76%, respectively. Notably, human activities played a crucial role in reversing the trend of grassland degradation in some hotspots. Finally, this study provides an essential scientific reference and support for realizing SDG 15.3 on global and regional scales.