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The number of extreme weather events in Germany will continue to increase
Photo: Boris Jordan / Getty Images
Ten weeks after floods and mudslides tore away entire towns in two German federal states, researchers are warning that the number of extreme weather events in Germany is increasing.
Flood disasters like the one from July 2021 are becoming more likely.
And they are becoming more common.
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The cause of these disasters is the climate crisis, caused and driven by people's greenhouse gas emissions.
The Extreme Weather Congress 2021 is currently taking place in Hamburg.
On this Friday, leading scientists will discuss how extreme weather events are changing as a result of climate change.
At the start of the conference, the German Weather Service and the Extreme Weather Congress Hamburg published a fact sheet: "What we know today about extreme weather in Germany" summarizes the current state of knowledge about extreme weather events in Germany.
Climate change is changing the weather in Germany
The experts state: In Germany, the number of some extreme weather events such as heat waves will increase in the future: »As a result of the rapidly advancing warming of the climate system, there is now a significant increase in extremely high temperatures Degrees Celsius and above a new phenomenon, ”says the report.
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Other extreme weather events, such as severe frosts, would, however, become rarer.
The authors rate the consequences of this development as "very serious".
And global warming is happening faster in Germany than in other parts of the world: since the beginning of comprehensive weather records in 1881, the temperature has risen by 1.6 degrees Celsius, according to the German Weather Service - significantly more than the global average.
However, this is not surprising, the authors explain, since land regions generally warm up faster than marine regions.
The tempo of temperature rise in Germany has increased significantly over the past 50 years: calculated over the period between 1881 and 2020, it was 0.12 degrees Celsius warmer in Germany every decade.
But in the past 50 years, since 1971, the rate of warming has already been 0.38 degrees Celsius per decade - more than three times the value.
Heat records fall reliably every decade: since the 1960s, every decade in Germany has been significantly warmer than the previous one.
The past decade, 2011 to 2020, was on average two degrees Celsius warmer than the first decades at the beginning of the records up to 1910. Nine of the ten warmest years since 1881 had only occurred in the new millennium.
The cause is clear to the authors: “Such an extraordinary accumulation of record years of temperature can only be explained by man-made global warming.
Random fluctuations or natural influences, such as volcanoes or fluctuations in solar radiation, are not an explanation for the global rise in temperature, «they write.
Up to 20 additional hot days in southern Germany
In many regions of Germany there has been a "massive accumulation of heat waves" since the 1990s, the report goes on to say.
With unchecked greenhouse gas emissions, a further increase of five to ten hot days per year in northern Germany and ten to twenty hot days in southern Germany is expected for the period between 2031 and 2060.
The increasing heat has consequences: The risk of forest fires is increasing, the soil is sometimes much too dry, the levels of the rivers are sinking so far that inland waterways can no longer operate.
How can the risk of flooding be better assessed?
Heavy rain events could also become more frequent due to the climate crisis.
According to the report, there is not enough data so far to provide definitive evidence.
However, radar recordings from the past 20 years indicated that the frequency of so-called heavy precipitation events is increasing significantly in some regions.
This makes disasters like the one in July this year more likely.
In a single day, more than 90 liters of rain per square meter fell in the region around the rivers Ahr and Erft.
Heavy and continuous rain also caused flooding in Belgium - and at least 220 people died.
An international team of scientists then examined the influence of climate change on the flood disaster in Rhineland-Palatinate and North Rhine-Westphalia.
The main focus of the study was on the two areas particularly affected by the extreme rainfall, the regions around the rivers Ahr and Erft, and the region around the river Maas in Belgium.
The result showed: The probability that there will be similar extreme rainfall increases by 1.2 to 9 times as a result of climate change.
The intensity of this extreme precipitation - due to man-made global warming - has increased between 3 and 19 percent in the region.
The damage is expensive
The number of violent thunderstorms is also increasing.
Information from insurance companies shows: The sums paid for damage after severe thunderstorms in Europe have been growing continuously for decades.
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Economist Claudia Kemfert also cites the cost argument when she campaigns for more climate protection.
Kemfert heads the Energy, Transport and Environment department at the German Institute for Economic Research in Berlin.
She told SPIEGEL: “The financial risks of climate change are underestimated.
And they keep increasing. "
The cost of reconstruction in the areas of the flood disaster alone would be estimated at 30 billion euros, according to Kemfert.
»We have to be clear: climate change costs, climate protection saves costs.
Every euro that is invested in climate protection saves 15 euros that would otherwise be caused by climate damage, «says the economist.
And it calls for people to take the risks of the climate crisis seriously and to prepare for them.
“Unfortunately, we have to be prepared for the fact that climate disasters will increase.
After all, we are now experiencing the effects of the past few decades.
We absolutely have to try to prevent a further exponential increase in greenhouse gas emissions - and thus also in extreme weather events. "
The intensity of the catastrophe in the Ahr Valley surprised even climate researchers, says Kemfert, and describes the events from the summer as a wake-up call: "The moment you feel climate change, the threat becomes clearer."
So what has to happen?
On the one hand, the economist sees a need for structural change: cities should prepare better architecturally for extreme weather events.
On the other hand, she sees national and international politics as having an obligation: “So far politics has not really been active.
Not only in Germany, it is above all civil society that has understood.
And wants the changes. "
