European summer droughts

euro med2k fig erl 19Researchers from the PAGES 2k Network Euro-Med2k subgroup have published a paper on the association between summer temperature and drought across Europe over both short and long timescales.

Placing recent drought in a 12-century-long perspective, authors identified that throughout history northern Europe tends to get wetter and southern Europe tends to get drier during warmer periods. They also observe that recent changes in drought patterns are not yet unprecedented.

Project leader Fredrik Charpentier Ljungqvist said these new findings are important as we are able to see for the first time that the relationship between summer temperature and drought seen in modern instrumental measurements has persisted for at least 12 centuries. "We can also see that the 20th century wetter trend in the north and drier trend in the south is not unprecedented over this time perspective," he said.

The new study, published in Environmental Research Letters, uses instrumental measurements since the 18th century and tree-ring-based reconstructions of temperature and drought, respectively, dating back from the 9th century.

Dr Charpentier Ljungqvist explains that the results have been compared with output from some of the same climate model simulations that are used to project future climate changes. "Crucially, climate model simulations suggest a too-strong link between warm and dry periods, and seem to underestimate the portion of Europe getting wetter in a warmer climate," he said. "It implies a possible exaggeration in the climate models of temperature-driven drought risks in parts of Europe under global warming. But the models may well instead underestimate future flood risks in northern Europe."

Access the paper "European warm-season temperature and hydroclimate since 850 CE" here.

This is the last product of the Euro-Med2k group, which wrapped up in 2017. Access the list of all the Euro-Med2k papers here.