Europe’s Shrinking Waterways Reveal Treasures, and Experts Are Worried

LONDON — Rusted chunks of metal from an old pickup truck disintegrate in the sun. Its windows, tires and interior are long gone, and so are any operable parts. It sits against a collection of hollowed-out homes and derelict buildings, all ruins of Aceredo, a former village in northwest Spain that was submerged three decades ago when a hydropower dam flooded the valley.

Now, because of a persistent drought, adventurers can tour this ghost village on foot.

Across Europe, once-submerged villages, ships and bridges — some dating back thousands of years — have re-emerged this year as rivers and reservoirs have dried up. The steady stream of gripping photos have circulated while much of the continent faced a string of extreme heat waves and a devastating drought, two phenomena that scientists say are made more likely and more severe by human-caused climate change.

The remains of Aceredo in northwestern Spain, including homes and trucks that usually sit at the bottom of a reservoir, have been visible since late last year. Credit…Clockwise from top left: Emilio Morenatti/Associated Press and Miguel Riopa/Agence France-Presse — Getty Images

The compounding impacts of drought and extreme heat have been clear.

In Spain, the Dolmen of Guadalperal, a four- to five-millennium-old megalithic monument often called the Spanish Stonehenge, rose from a drought-hit dam west of Madrid. In Italy, where residents are facing its worst drought in 70 years, ruins of an ancient Roman Neronian bridge are visible in the Tiber River. One of Germany’s largest reservoirs, the Edersee, has shrunken so much that the foundation of Berich, a village that was flooded in 1914, can be seen. In Prahovo, Serbia, water levels in the Danube River have fallen so low that more than a dozen sunken Nazi Germany World War II boats are now exposed. And in Northern England, falling water levels at Baitings Reservoir have revealed an ancient packhorse bridge.

“It’s hugely concerning,” said Yadvinder Malhi, a professor of ecosystem science at the University of Oxford. “It’s a sign that there are big shifts going on in the stability of the global climate and the regional weather that’s going to cause more and more stress on human systems and natural ecosystems.”

Because humans have heated the planet about 1.1 degrees Celsius (2 degrees Fahrenheit), there is much more variability in the climate than expected, Dr. Malhi said. He added that if warming reaches 2 degrees or more, humans can expect to see far greater impacts than initially feared.

“As there is more energy in the atmosphere, we’re getting more and more extremes, whether it’s flooding extremes,” like in Pakistan, he said, “or drought extremes like we’re seeing in Europe, China and part of North America.”

These sorts of events were largely expected around 2040, and to see them now strongly indicates that climate variability is occurring more rapidly than most thought, Dr. Malhi said.

Friederike Otto, a senior lecturer at the Grantham Institute at Imperial College London, said the wide interest in shrinking riverbeds and reservoirs across Europe can be attributed to the visual impact of extreme heat.

“Heat has always been a bit of a neglected or ignored extreme event because the impacts are not so obviously visible as with floods or storms,” she said. “I think that this year, because we have this heat combined with a drought — and also the heat was very extreme, we have all these rivers drying up — it makes it much more visual.”

Much of the growing crop of re-emerging artifacts and ruins are scattered over the Mediterranean, one of the few areas of the world with a “large drying,” Dr. Otto said.

“The stuff found in the Mediterranean is probably something we will get used to seeing, because there, we will have more and more of these very dry, hot years,” she said. The discoveries in other parts of Europe are more unusual, she said.

While some of the images this summer — graphic hunger stones being discovered in Germany, a 450-kilogram World War II bomb being removed from a riverbed in Italy and sheep taking shelter underneath a medieval bridge on the dried bed of the Guadiana River in Spain — are eye catching, Europe last saw a significant drought not that long ago, in 2018. But this time, it’s more severe.

In northwest Spain, the old village of Aceredo began emerging from the depths of the Alto Lindoso reservoir in November 2021, at the beginning of what is now a severe drought. By the start of the year, Spain was experiencing its driest January in 20 years, and by February, the reservoir had fallen to 15 percent of its capacity, exposing the remnants of Aceredo. Conditions have not improved much over the summer.

Clockwise from top left: Low water in Worms, Germany, revealed a hunger stone carved during an earlier drought; the ruins of Sant Roma de Sau, an 11th-century church that was submerged in the middle of the 20th century to build a reservoir in Catalonia, Spain, reappeared when the water level was low; wreckage of a World War II German warship in the Danube in Serbia; and sheep sheltered from the sun underneath a medieval bridge on the dried bed of the Guadiana River in Spain.Credit…Clockwise from top left: Tilman Blasshofer/Reuters, Josep Lago/Agence France-Presse — Getty Images, Darko Vojinovic/Associated Press and Susana Vera/Reuters

“The degree of this drought is on the once-in-a-century or several-centuries-time-scale intensity,” Dr. Malhi said, adding that while extreme droughts do occur normally, the challenge is the frequency of these events increasing over time.

Parts of Europe may not fully recover from the current drought, Dr. Otto warned, particularly along the Mediterranean, where dry summers are expected to continue.

“We have an awful lot still to learn,” she said, when asked what the discoveries reveal about the state of Europe. “I think it says that climate change, particularly in Europe, is always discussed as something happening in the future. It’s not in the future. It’s happening now.”