Abstract
Land degradation is holding back attainment of the Sustainable Development Goals and exacerbating global heating. Land degradation and improvement since 1981 have been assessed by proxy using remotely sensed Normalised Difference Vegetation Index (NDVI), translated into net primary productivity. The quantitative data show the extent and trends of changes over four decades and identify where further action is needed. During 1981–2021, 28.5% of land was degrading—most notably through megafires in boreal forests, land clearance and cultivation in sub-Saharan Africa and the East Indies and across the steppes. The degraded area increased by 4.5% compared to 1981–2003 yet affected fewer people—1.2 billion compared to 1.5 billion. Consistent policies on sustainability increased biological productivity on 26% of land (10.5% more than 1981–2003), particularly cropland in China, India and the European Union; 2.9 billion people now live in the improved areas compared with 0.8 billion in the improving areas of 1981–2003.