While summer thunderstorms have provided sporadic relief for parched fields over the past week, farmers, scientists and politicians say global warming is triggering multi-year droughts – 2018 and 2019 have also been dry – and modifies the climate of continental Europe in such a way as to affect agriculture and the rest of the economy.
July of this year was the driest month in France since 1959 according to the national weather office, with less than a third of normal precipitation, while the average temperature between January and July was the highest since start of his records.
Meanwhile, Germany experienced one of its driest spring seasons in more than a century this year, and rainfall in July was almost 40% below normal, raising fears of a potential repeat of the fall in water levels on the Rhine and other major rivers two years. This disrupted shipping and hit the country’s economy.
“The heat roasted everything,” explains Clément Traineau, a cattle breeder near Angers sur la Loire. “We didn’t have a drop of water in July.”
Researchers led by the Helmholtz Center for Environmental Research said in an article published in Nature this month that the combined droughts of 2018 and 2019 in continental Europe were “unprecedented in the past 250 years, with substantial implications for the vegetation health ”.
The successive droughts of the last two decades have resulted in losses estimated at 100 billion euros and, in the worst case of greenhouse gas emissions, such events would be seven times more likely in the second half of this century , said the authors of the article.
According to estimates from the French Ministry of the Environment’s Explore 2070 project, average air temperatures are expected to increase by 1.4 to 3 degrees centigrade over the next 50 years, precipitation will decrease by 16 to 23%, and flow of rivers will decline between 10 and 40 percent.
Drought episodes are already starting earlier in the year and ending later than before, according to Denis Caudron, coordinator of the French Fund for the Conservation of Wild Rivers.
“It rains less and it is distributed differently throughout the year, and it snows less too – the snow cover in the Alps, the Pyrenees and the Massif Central is not what it used to be,” he said. -he declares.
Although there was good rainfall during France’s warm winter, which replenished depleted aquifers, the topsoil has been unusually dry since July.
Farmers, scientists and politicians say global warming is increasingly becoming an economic challenge.
“In 2018, the interruption of navigation on the Rhine reduced German economic output by 0.4 percentage point and weighed on fuel prices for two quarters,” said Carsten Brzeski, economist at ING. “Is this something we’re watching?” Yes. But is it easy to predict? No. ”
According to Jörg Uwe Belz of the German Federal Institute of Hydrology in Koblenz, the Rhine, a vital route for international trade, flows 30% below its usual level in Kaub, a major bottleneck between Koblenz and Mainz .
While the river is still 1m above the low-water threshold to which navigation could be restricted, he said water levels will continue to decline until November.
“It all depends on the rainfall,” Belz said. “If we have rain it will be fine, but if the drought continues we will have problems.”
Ulrich Roth, water engineering consultant and professor at the University of Frankfurt, said climate change appeared to be contributing to the low levels of the Rhine.
“Melting glaciers usually provide a certain amount of water for the Rhine and due to climate change they are getting smaller and smaller each year,” he said – because less snow and ice forms each winter, resulting in less meltwater emerging in the summer.
For the moment, governments are engaged in crisis management. Local authorities in the states of Rhineland-Palatinate and Hesse in western Germany have banned garden hoses in recent days.
French authorities have imposed water restrictions on all or part of 78 of the country’s European departments, while also trying to help its 450,000 farmers – for example by providing emergency financial assistance and relaxing environmental rules .
“We are taking exceptional measures to help farmers weather episodes of drought which recur over and over again,” Agriculture Minister Julien Denormandie told French radio last week.
But he acknowledged that the farming strategy is expected to change in the longer term and said that an official economic stimulus plan to be unveiled in Paris next week in response to the coronavirus crisis would include measures “to adapt our farms to the effects. of climate change ”.
Farmers are already switching crops and methods, with more vines and sunflowers, for example, grown further north, and irrigated, thirsty maize sometimes replaced with sorghum. Delicate white wines are increasingly produced in a refrigerated cellar due to the difficulties of vinification at high temperature.
Christian Huyghe, scientific director of agriculture at the French National Institute for Agronomic Research, said policymakers and farmers were mostly convinced that droughts were periodic misfortunes whose effects could be mitigated by more irrigation and other safety measures.
“For the next 15 years, this is the easiest option,” he says.
After that, however, it would require changes in crop selection and management, as well as progress in reducing greenhouse gas emissions from farms which are disproportionately high given their share in economic production, a he warned. “There is too much urgency to say that we have the time and that we can wait.”