“I SAW a tree with people sitting in it, crying and screaming. I could hear them despite all the noise. But I couldn’t help them. I didn’t know what to do,” says Melanie Schultz-Coerne, crying too as she recalls the traumatic night last year when Germany experienced its worst floods in six decades. She doesn’t know what happened to the campers she saw, but 134 people in the country’s Ahr valley died during the floods in mid-July, with hundreds more injured.
The increasing threat of such extreme weather events and their economic and human costs will come to the fore on 28 February when scientists release a major assessment of the impacts of climate change and, crucially, how we adapt to them (see “A road map for adaptation“). The last version of this report, published by the Intergovernmental Panel on Climate Change (IPCC) in 2014, identified the harm wrought by floods as a key risk facing Europe.
One of the worst-hit areas last year was Ahr, named after the usually placid river snaking through it. Weeks after the flood hit Ahr, , finding the event to be a 1-in-500-year disaster.
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Walking alongside the Ahr now, it is hard to imagine the river wreaking destruction on this affluent wine-growing region, which is popular with hikers and tourists. “We were a little paradise, with vineyards, a small river, bicycles. Then, one night, everything’s gone,” says Markus Kelter in Walporzheim. Standing in the gutted interior of the house where his family have lived since the 19th century, he is thankful that this time only the building was damaged. In 1804, children in his family died in a flood here.
The conditions for the 2021 flood were foreseen, says Frank Kreienkamp at Germany’s National Meteorological Service. A low-pressure system sat in place for days, drawing warm, wet air from the Mediterranean that fell as rain over a wide area of north-west Europe. The extent and duration of the rain was striking, leaving the ground saturated and setting the stage for a historic event, says Kreienkamp. Rain on the day of the floods was heavy but not extreme – 100 to 150 millimetres – but it was too much for the valley.
The area’s steep hills and flat floodplain amplified the impact. Water was funnelled through the valley, destroying more than 80 bridges, many of them formidable stone structures that were hundreds of years old. Travelling through the valley seven months on, you see that the skeletons of some bridges stand by temporary pontoons. Railway tracks remain swept away; piles of wood, mud and other debris stand by the roadside; and high watermarks remain above ground-floor height on many buildings.
Despite these lasting scars, a colossal recovery effort is under way. Alongside an army of official contractors rebuilding roads and infrastructure is a movement of volunteers, with many travelling from across Germany to help Ahr.
While there has been occasional hostility to these helpers – some are on an “ego trip taking selfies”, says one local – they have also been welcomed, as the “Danke”, “We Ahr Valley” and other messages daubed on damaged buildings attest. “This has been the biggest intervention in our history,” says Sabine Lacker at the Federal Agency for Technical Relief, which coordinated nearly 17,000 volunteers in Ahr over six months.
However, much of the aid has been self-organised. Schultz-Coerne has been serving food at a makeshift canteen for more than 12 hours a day to volunteers clearing up around her village, Mayschoß. “It definitely was a way to help myself too,” she says.
Thomas Putz, whose medical supplies business in Bad Neuenahr-Ahrweiler was flooded, responded by creating the “Helper Shuttle”, using social media to rapidly coordinate thousands of volunteers. The aid involved not just clearing mud and debris, but also helping people who were grieving. “We don’t only need your muscle, we need your ears,” Putz told volunteers.
“We were a little paradise, with vineyards, a small river, bicycles. Then, one night, everything’s gone”
Guido Orthen, the mayor of Bad Neuenahr-Ahrweiler, says the challenge is long term. “The reconstruction of our city is a mammoth task,” he says. Power and water were restored within weeks, schools have resumed and pop-up shops have been created. Nonetheless, he thinks restoring all infrastructure, from roads and lighting to parks and playgrounds, will take five to 10 years due to the sheer amount of damage. “We still have a long way to go,” he says.
Meanwhile, questions are being asked about what lessons can be learned. “Germany seems to have been unprepared in terms of the disaster unfolding,” says Alexander Fekete at Cologne University of Applied Sciences. The weather was forecast and early warnings issued to local authorities, but those didn’t always make it down to officials and residents in Ahr, says Fekete. A mobile phone broadcasting system went unused and there were no sirens when the floods hit: Putz resorted to throwing sandbags at buildings to wake people in the night.
While some people have left in the flood’s aftermath, several tell New Scientist they are committed to the area. Leonard Kneips, a young construction worker temporarily staying in a “tiny house” while he waits for his flat in Mayschoß to be renovated, says he will stay. He is fatalistic about the prospect of more floods as the world warms. “If it happens, it happens,” he says.
Researchers agree that the risk of flooding in Europe is increasing. Warmer air holds more water and climate change may also be increasing the chance of weather systems getting “stuck” like they did last July, due to a weakening of the jet stream. But that is still just a hypothesis, says Friederike Otto at Imperial College London.
The events have shown that even with today’s level of warming – about 1.1°C globally since the industrial revolution – adaptation will be hard and sometimes impossible in high-income countries, let alone poorer ones. There is little Ahr could have done to prepare for these freak floods. “It showed that everyone is affected by climate change. Sometimes we think, in Europe, we are rich and can deal with it,” says Elco Koks at the Free University of Amsterdam.
A mixed picture
Ahr’s recovery offers a mixed picture on future-proofing homes for more extreme weather or to contribute less to climate change. Some houses’ oil-based heating systems, which spilled and contaminated water during the floods, are being swapped for lower-carbon options. But in most cases, homes are being rebuilt with little sign of adaptation, such as moving living areas above the ground floor.
Nonetheless, last July’s events have influenced the discourse on climate change nationally. “This event changed everything,” says Enno Nilson at the German Federal Institute of Hydrology. He says there is now a big focus on flood risk in addition to drought, which had been the main area of discussion for climate impacts in Germany, following wrecked harvests in 2018.
The floods have changed how people think in Ahr, too. Alexandra Preste at Deutzerhof vineyard says the valley’s topography used to make people feel safe, and the floods flipped that. “I felt we were living in the promised land. It’s like we’ve lost our innocence,” she says. But that could lead to more climate action, she says. “People only change their behaviour when they see something.”
A road map for adaptation
Scientists in Working Group II (WGII) of the Intergovernmental Panel on Climate Change are currently agreeing the final version of a landmark report on the impacts of climate change and how we might adapt to them. This is the second of four documents comprising the sixth in a series of “assessment reports”. The first document, published last year, found that humanity’s role in warming to date was “unequivocal”. A third, due in early April, will focus on how to avert catastrophe by curbing emissions and removing carbon dioxide from the air. The fourth, to be published in September, will synthesise the previous three.
Debra Roberts, a co-chair of WGII, says the report will have a more detailed regional breakdown of impacts than in the past because “people respond to places they know”. A stronger focus will be given to climate impacts in cities, such as heatwaves. More emphasis will be placed on the differing vulnerability and exposure of people around the world, depending on their ability to pay for ways to adapt. The report is also expected to highlight the “implementation gap” between what researchers say needs to be done – from better flood defences and planting new crop varieties to cooling cities with trees – and what is happening in reality.
