Oct 25, 2017

Observed drought indices show increasing divergence across Europe

James H. Stagge, Daniel G. Kingston, Lena M. Tallaksen, David M. Hannah
Scientific Reports
  • Asks:
    • How have various types of European drought changed?
    • How do these changes compare with climate projections?
    • What are the causes of observed differences?
  • Reveals, for the first time, a regional divergence in drought likelihood as measured by the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI) across Europe over the period 1958–2014 
  • Finds that this divergence is driven primarily by an increase in temperature from 1970–2014, which in turn increased reference evapotranspiration (ET0) and thereby drought area measured by the SPEI
  • Analysis shows increasing drought frequencies in southern Europe and decreasing frequencies in northern Europe
  • Finds that increases in temperature and ET0 have enhanced droughts in southern Europe while counteracting increased precipitation in northern Europe
  • States that this is consistent with projections under climate change, indicating that climate change impacts on European drought may already be observable