Two major drought indices in Europe are deviating from each other in a way that’s consistent with many climate change simulations — further gaining ground in the march towards the attribution of major events like droughts to climate change — according to a new study published in the journal Scientific Reports.
Image via NOAA/Earth System Research Laboratory
“This is one more big drop in the bucket toward climate change attribution,” commented lead author James Stagge of Utah State University’s Utah Water Research Lab. “There have been a lot of projections, but now that we’re starting to see the projections and observations line up, it’s not a question of ‘is it happening?’ It’s a question of ‘how much?’ And ‘what do we do?'”
The observations by the researchers match earlier work predicting that drought frequency would decrease in Northern Europe and increase in Southern Europe as the result of climate change.
“Once you add in the temperature increases for all of Europe, you have all the hallmarks of climate change,” Stagge noted.
Speaking about the effect of evapotranspiration on drought occurrence, Stagge stated: “When you include evapotranspiration, the border from where it’s getting wetter to where it’s getting drier is pushing farther and farther north. So it’s not just the Mediterranean that’s getting drier. It’s pushing up into Germany and England. It’s moving everything farther north.”
The press release provides more: “This increasing deviation in European drought frequency is observed from the 1980s until today. In a stationary climate, Stagge and co-authors say they would expect this difference to be randomly distributed and stable like it was from the 1950s through the 1970s. ‘This recent and consistently increasing trend is a clear signal, not random noise,’ he added.
“Stagge says the new findings are important to the scientific community and could influence public policy and Europe’s agriculture industries. Many drought monitoring agencies use the indices to determine what constitutes drought, and insurance pilot programs have considered using them to determine whether or not farmers are entitled to compensation if drought affects their region.”
“The research highlights the increasing need to carefully define drought in a changing climate,” explained Stagge. “Indices that were standardized in the past may drift significantly in a changing climate depending on how a data set is measured and what time period is considered.”
As a reminder here, Southern Europe is expected to experience large amounts of desertification over the coming decades and centuries as the climate warms. And in the short term, extreme heat waves like the recent “Lucifer” heat wave will be becoming much more common.