The magnitude of the floods in Germany shocks scientists
“It is not just about what happened here, but about the set of extreme phenomena that we are witnessing,” said German Chancellor Angela Merkel, after visiting an affected area. “We have to reflect on how we should act to move towards climate neutrality.”
Are they related to climate change?
Almost certainly. Scientists have long predicted that alterations to the climate will lead to more extreme events, such as heat waves, droughts and floods.
The gases emitted by engines and emissions from burning forests and other human activities are warming the planet. As the atmosphere warms, it retains more moisture, causing it to rain more. In Germany, Belgium, the Netherlands, Edinburgh, Tokyo, and London, the places that have suffered recent floods, there would have been heavy summer rains even without a climate crisis, but it is unlikely that they would have been such intense floods.
What evidence is there?
First, more records are being broken and more frequently: the world’s seven hottest years since there are records occurred after 2014. Second, scientists can now use statistical analysis and computer modeling to calculate the increase in the likelihood of certain weather events occurring as a result of additional pressure from humans on the climate system.
For example, human emissions made the deadly “heat dome” that hit Canada and the northern United States in June at least 150 times more likely. It also multiplied by more than 600 probability of prolonged heat wave of Siberia in 2020.
According to Richard Betts, head of climate impacts research at the Weather Service’s Hadley Center, these calculations eliminate the argument that “extreme weather events are going to happen anyway, so you don’t have to worry about them.”
There is still no attribution study for the latest floods in Europe because it is a more time consuming analysis.
Jet stream disturbance?
It is an important unknown. Climate scientists are considering it as one of the possible explanations for the unexpected increase in some recent records. On Wednesday, rainfall in the Stammheim stationin Cologne, they reached 155 millimeters in 24 hours, beating the city’s previous record for rainfall in a single day, which stood at 95 millimeters.
Two weeks ago, temperatures in Lytton, Canada, surpassed by no less than 5 degrees Celsius the previous daily heat record for the boreal country.
These figures exceed the models that predict bad scenarios as a result of bad luck or other factors that alter the climate suffered in other regions. One possible explanation, therefore, is that the loss of ice in the Arctic has made the jet stream more erratic.
There is still no consensus among scientists on this issue, but experts are increasingly concerned about the possibility of a world heading for a more rugged landscape than previously thought.
Treatment in the media
In some media, the role of the climate emergency in these extreme events is underestimated as if it were part of a deliberate strategy against climate science and against political efforts to reduce emissions. But custom also plays an important role. For decades, journalists have represented heat waves as good news that is illustrated with images of bathers, swimming pools and ice creams.
An excess of prudence can also make journalists hesitant to establish a relationship with the climate crisis. On Wednesday, climatologist Ed Hawkins criticized the BBC for that and for not being up to date with science. He suggested that journalists use the following phrase in the future: “Experts say that climate change is already increasing the frequency of extreme weather events and many isolated events have been shown to have worsened due to global warming.”
Translated by Francisco de Zárate