• DOI:10.1126/science.1192666
• Corpus ID: 35188485

Drought-Induced Reduction in Global Terrestrial Net Primary Production from 2000 Through 2009

@article{Zhao2010DroughtInducedRI,
  title={Drought-Induced Reduction in Global Terrestrial Net Primary Production from 2000 Through 2009},
  author={Maosheng Zhao and Steven W. Running},
  journal={Science},
  year={2010},
  volume={329},
  pages={940 - 943}
}

• Maosheng Zhao, S. Running
• Published 20 August 2010
• Environmental Science
• Science

Reversing the Trend Terrestrial net primary productivity (NPP, the amount of atmospheric carbon fixed by plants and accumulated as biomass) increased from 1982 through 1999, which has been attributed to factors such as nitrogen deposition, CO2 fertilization, forest regrowth, and climatic changes. Zhao and Running (p. 940) used satellite data to estimate global terrestrial NPP over the past decade and found that the earlier trend has been reversed and that NPP has been decreasing. Combining this result with climate change data suggests that large-scale droughts are responsible for the decline. Future widespread droughts caused by global warming may thus further weaken the terrestrial carbon sink. Terrestrial biomass declined during the hot past decade, reversing the trend of the previous 20 years. Terrestrial net primary production (NPP) quantifies the amount of atmospheric carbon fixed by plants and accumulated as biomass. Previous studies have shown that climate constraints were relaxing with increasing temperature and solar radiation, allowing an upward trend in NPP from 1982 through 1999. The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP, and a drying trend in the Southern Hemisphere has decreased NPP in that area, counteracting the increased NPP over the Northern Hemisphere. A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production.