After historic rainfall that caused devastating floods that killed more than 100 people in northwestern Europe and left more than 1,000 missing, officials and scientists are not shy about the main culprit: climate change.
In response to images of the ongoing disaster, German Environment Minister Svenja Schulze ad, “These are the warning signs of climate change that have now arrived in Germany.” European Commission President Ursula von der Leyen called the floods “a clear indication of climate change” and “something that really, really shows the urgency to act”.
That European officials draw a direct line between this extreme weather event and climate change may not come as such a surprise, given that it happened just a day after the European Union ad a broad set of proposals to tackle the climate emergency – proposals that risk meeting stiff opposition from many sectors, including less wealthy EU countries or those heavily dependent on fuel fossils.
A catastrophic weather event immediately following the announcement of these proposals certainly helps EU officials illustrate why such ambitious policies are needed.
But it’s not just officials who make the connection between flooding in Europe and global warming: even scientists who in the past have been reluctant to explicitly link an extreme weather event to climate change are clear that the change climate probably played a role here.
“The precipitation that we have experienced across Europe in the last few days is extreme weather conditions that are intensified by climate change – and will continue to increase with warming”, Friederike Otto of Environmental Change Institute of the University of Oxford told German newspaper DW.
This flooding in Germany today is difficult to understand. It really looks like the planet is trying to tell us something pic.twitter.com/o5vCEpk8mk
– Read Parable of the Sower by Octavia Butler (@JoshuaPotash) July 16, 2021
This new desire to make these explicit links is in part due to advances in attribution science. As Umair Irfan of Vox explained, âThe researchers have a lot more data show how climate change affects the frequency and likelihood of heat waves (and the fires that follow them), ocean heat waves, droughts and intense storms.
In other words, the more extreme weather events that occur, the more opportunities scientists have to learn just how severe the impact of climate change really is.
How climate change can produce extreme precipitation
Germany’s national weather service said the two worst-affected states, Rhineland-Palatinate and North Rhine-Westphalia, recorded between 4 and 6 inches of rain within 24 hours between July 14 and July 15. According to CNN meteorologist Brandon Miller, that equates to nearly as much as the region usually sees in a month.
There are two main links between climate change and extreme precipitation events like the one in northwestern Europe. First, like Hayley fowler, professor of climate change impacts at the School of Engineering at Newcastle University, told me that a warmer atmosphere can hold more moisture. “According to Clausius-Clapeyron equation, a one degree increase in temperature has the potential to give you a 7 percent increase in precipitation intensity, âFowler said.
âThe second point is that the [Earthâs] the poles rise in temperature at two to three times the rate of the equator, âFowler said. This, she said, “weakens the mid-latitude jet stream, which is mostly over Europe. In summer and autumn, the weakening jet stream has a ripple effect. causing slower thunderstorms. So there is a double whammy of increasing intensity, but the storm also persists longer. ”
And that kind of double whammy can have devastating effects on land and infrastructure.
âIt all happened very quickly, and I have never experienced a situation that developed so quickly,â said Tanja Krok, head of the German Red Cross volunteer service in North Rhine-Westphalia. -Westphalia. She has worked in the region for almost 30 years. “In 2002, we had floods in eastern Germany, but it impacted one region and developed slowly, âKrok said.
The powerful current of water has also caused landslides, leaving some roads unusable if not completely washed away. âWe’ve never had a landslide before. We have the impression that our houses here are stable and fixed. It’s not often that you see houses collapsing, âKrok said.
Europe’s flood warning system is also to blame
In addition to climate change, experts also pointed to communication failures in the European flood awareness system.
German weather service issued warnings for the event Monday, three days before that actually happened. The hydrological services in Germany have also issued a warning. Given the number of warnings in place, experts said the problem was not so much forecasting as communicating the severe impacts of flooding to the general population.
âThe problem is not that there was no warning in place. There was. We now have some very good forecasting models. So for both of these events, as well as the flooding we saw in New York and London earlier in the week, flood warnings have been put in place for these. We knew that heavy rains were coming â, Linda speight, a flood forecasting specialist at the University of Reading in England, told me.
âMore than 100 people should not have died in a flood in Germany. This is not expected to happen in Western Europe in 2021, âshe said.
Speight, who works at the junction of hydrology and meteorology to understand how weather will cause flooding, believes the high toll could be due to people not understanding the seriousness of the warnings.
âIf you issue a weather warning that says there’s going to be 200 millimeters of rain tomorrow, that doesn’t mean anything. It doesn’t mean much to me – and it’s my area of ââexpertise, so I doubt it means a lot to the general public, âSpeight said. âWe need to change the way we communicate warnings. For example, instead of saying, âThere will be 200 millimeters of rain,â we have to say, âThere will be a rapid rise in water levels, damage to properties, a risk to life.
And as extreme weather events like these become more common, learning to communicate danger effectively will be even more critical. âAll over the world we need to better prepare for these kinds of events,â said Speight. âAnyone can learn the lessons from the floods in Germany and see how to apply them to improve and be better prepared in their own country. “
But while early warning systems can help reduce loss of life, the ultimate answer is for humans to stop emitting carbon dioxide and other greenhouse gases that heat the planet.
âThe climate is getting warmer, and it will continue to get warmer as long as we emit CO2. The last time I checked, we are still emitting huge amounts of CO2, âsaid Geert Jan van Oldenborgh, visiting professor at the University of Oxford who studies the impact of climate change on extreme weather events.