Increased growth rate (1982-2013) in global grasslands biomes

Across the Earth's surface, climate change has been occurring at a non-uniform rate, affecting biomes and directly or indirectly imposing impacts on societies. The productivity of the grassland biome has also been inevitably influenced, which in turn might affect the livestock production. Here, a meaningful indicator - growth rate index (GRI) - is proposed based on plant phenology and quantified from long-term remote sensing data to understand responses of the grassland biome to climate change at a global scale. We found a steady increase in GRI for the global grassland biome from 1982 through 2013, with around 35% of global grasslands exhibiting a significant increase (p<0.1), and 3.8% of global grasslands experiencing a decrease. Climate warming over the past three decades did not aggravate water stress on worldwide grassland biomes, especially for the typical steppes in the Northern Hemisphere where GRI appeared more sensitive to the variations in precipitation compared to the savanna biome in the Southern Hemisphere. This study suggests that the increases in grassland GRI may have the potential to elevate global livestock production.