The Danube River has fallen to its lowest levels in decades across south-eastern Europe, exposing relics from the Second World War and prehistory while triggering an energy crisis. Near the Serbian village of Prahovo, about 20 German warships have become visible on the riverbed. The vessels, part of the Nazi Black Sea fleet, were deliberately scuttled in 1944 as German forces retreated from the advancing Red Army; some still contain live ammunition and explosives. Further downstream in Bulgaria, animal bone fragments found at Ryahovo were identified by Nikolay Nenov, director of a local history museum, as most likely belonging to a woolly mammoth (Mammuthus primigenius), well-preserved and probably from a single animal.

The shrinking river has also starved the cooling systems of nuclear power plants. In Hungary, the Paks facility—which normally supplies roughly half of the country’s electricity—was forced to shut down three of its four reactors in early August, with the remaining unit running at half power. Days later, the plant was operating at only a tenth of its normal capacity. Visiting the site, Prime Minister Péter Magyar warned that “there are a few critical days left” and called for national unity in conserving electricity. Government buildings in Budapest switched off decorative lighting, and households were urged to avoid using washing machines during peak evening hours.

Romania’s Cernavodă nuclear plant also faced cooling water shortages. Naval engineers detonated explosives to clear underwater rocks and dug temporary channels to divert more water towards the reactors. Downstream, a cruise ship with nearly 200 passengers ran aground near the Bulgarian port of Vidin after water levels dropped, forcing an evacuation.

The drought is not confined to the Danube. On the Rhine, a vital commercial artery, the water level at the Kaub choke point fell to just 24 centimetres, the lowest since records began in 1880, forcing cargo vessels to slash loads and sending freight rates soaring. Europe is the world’s fastest-warming continent, heating more than twice as fast as the global average, according to the EU’s Copernicus monitoring group. Richard Allan, a climate science professor at the University of Reading, said the current hydrological extremes are “only the tip of the iceberg” of global warming’s impacts, and that only rapid cuts in greenhouse gas emissions can limit future crises.