Severity of drought and heatwave crop losses tripled over the last five decades in Europe

This paper discusses how extreme weather disasters (EWD) can jeopardize domestic food supply and disrupt commodity markets. However, historical impacts on European crop production associated with droughts, heatwaves, floods, and cold waves are not well understood - especially in view of potential adverse trends in the severity of impacts due to climate change.

Here it combines observational agricultural data (FAOSTAT) with an extreme weather disaster database (EM-DAT) between 1961 and 2018 to evaluate European crop production responses to EWD. Using a compositing approach (superposed epoch analysis), we show that historical droughts and heatwaves reduced European cereal yields on average by 9 and 7.3%, respectively, associated with a wide range of responses (inter-quartile range +2 to -23%; +2 to -17%). Non-cereal yields declined by 3.8 and 3.1% during the same set of events. Cold waves led to cereal and non-cereal yield declines by 1.3 and 2.6%, while flood impacts were marginal and not statistically significant. Production losses are largely driven by yield declines, with no significant changes in harvested area.

While all four event frequencies significantly increased over time, the severity of heatwave and drought impacts on crop production roughly tripled over the last 50 years, from –2.2 (1964-1990) to -7.3% (1991-2015). Drought-related cereal production losses are shown to intensify by more than 3% per year. Both the trend in frequency and severity can possibly be explained by changes in the vulnerability of the exposed system and underlying climate change impacts.