The secrets of the River Danube revealed by drought - from a woolly mammoth to Nazi motorbike - as Europe's heatwave continues

As Europe braces for yet another heatwave, the relentlessly dry conditions that have left the continent gasping for breath have also revealed many of the secrets once long-held by the River Danube. 

Running through ten countries across central and southeastern Europe, it has played an important role in trade and conflict on the continent for millennia. 

Alexander the Great is said to have pushed tribes his Macedonian kingdom was warring with as far back as the Danube in the sixth century BCE. 

Now, amid the drought that has left Europe parched, this complex history is revealing itself.  

Among the most surprising things to have been unveiled by the lowered waterline of the Danube are the remains of an ancient woolly mammoth. 

Scientists were seen gathered around a large bone that was spotted in the banks of the river near the Bulgarian town of Ryahovo. 

So far they have identified a jaw bone, fragments of tusks, part of a shoulder blade and a femur with its articular head among the stash found at the end of July. 

The bones were remarkably well-preserved. Photos appear to show teeth still lining the jaw bone that was found. 

The ancient beasts co-existed with early humans, who hunted them for food and used their tusks and bones as tools. 

A Nazi-era motorcycle was also found after the water levels of the Danube sank to record lows, this time in Hungary's capital, Budapest. 

The vehicle, which was spotted on the shores of the river opposite the country's parliament building, was hauled out and cleaned up by military personnel. 

Despite it being thoroughly rusted, the motorcycle had retained its form after decades under the water. 

It has since been put on display at the depot of the Military History Institute and Museum of the Defence Ministry in Budapest. 

Several Nazi-era warships were also found across the Danube. 

One was spotted in front of Djerdap II, a large dam on the Danube River, between Romania and Serbia, near Prahovo, Serbia. 

This was all but destroyed, though large parts of it still remained intact.  

Another, meanwhile, was seen on the riverbed in Baja, Hungary. Large parts of the hull remained together, as well as what appeared to be a motor. 

And in Bulgaria's Gigen, the foundations of the ancient Constantine Bridge, commissioned by Roman emperor Constantine I and inaugurated in 328AD, were spotted as the water level reached record lows. 

Though the lowered water levels of the twisting river may have provided historians with revelatory new material to investigate, it has also presented a huge problem for Europe's infrastructure. 

Hungary was forced to switch off its only nuclear plant earlier this month as the water from the Danube that cools it could not reach the reactor.

The river fell to record lows in recent weeks amid a prolonged heatwave and drought across much of Europe, forcing the plant to operate at only around 10 per cent of its capacity with only one of its eight turbines left running.

Droughts this summer have wreaked havoc in European power production, shipping and public health systems, and the hit to the region's economy can already be measured in the hundreds of billions of euros.

Similar problems in Romania for instance have forced the declaration of a state of energy emergency throughout August, and the flow of the Danube has been redirected to allow its sole nuclear plant to continue operating for the next few days.

Hungarian Prime Minister Peter Magyar said on Monday that work to restart a second turbine at Paks began after the Danube rose 19 centimetres above last week's low.

The second turbine was expected to start generating electricity on Monday evening, he said on Facebook.

Mr Magyar flagged the possibility of increasing output last week, saying that expected rainfall in Austria could raise Danube levels, but cautioned that the rise would be temporary.

Mr Magyar also said last week that the government was working on longer-term solutions, including reviewing the planned Paks 2 expansion of the plant as current designs also make the planned new plant dependent on cooling water from the Danube.

It was key to keep the nuclear plant working, Mr Magyar said last week, as 'the Hungarian economy cannot work without the plant for months'.

The government has also decided to diversify its energy supply, with Mr Magyar saying the government will tender 700 megawatts of wind power generation capacity by August 31 and develop four gigawatts of wind capacity by 2030.

Western Europe experienced its hottest June-July on record as climate change fuels an historic summer of heat, drought and wildfires across the region, the EU's global warming monitor said Monday.

Europe is the world's fastest-warming continent and the first two months of summer have been marked by successive heatwaves, scorching temperatures and bone-dry conditions.

The Copernicus Climate Change Service said the combined average temperature in western Europe for June-July was 21.62C – beating the 2022 record for the same period.

This reflected 'the exceptional persistence of heat' so far this summer, Copernicus said.

Levels of soil moisture were 'significantly lower' than in July 2022 when the last severe drought gripped western Europe, Copernicus added.

'This is a clear example of how climate change is intensifying heat extremes, with heat and drought increasingly reinforcing one another,' said Samantha Burgess from the European Centre for Medium-Range Weather Forecasts, which operates Copernicus.

Spain's national weather agency AEMET said today that July was the country's joint-hottest month since records began in 1961. 

The average temperature of 25.7C was 2.6C higher than the 1991-2020 reference period and tied with July 2022 as the warmest month, AEMET said in a statement.

Last month was also mainland Spain's driest July on record as 4.3 millimetres of rain fell, which represented just 26 per cent of the normal precipitation for the time of year.

Scientists have long warned that human-driven climate change, caused by the burning of fossil fuels, is increasing the length, frequency and intensity of extreme weather events such as heatwaves.

Of the ten warmest months of July recorded in Spain, eight have occurred in the 21st century, AEMET said.

The southeastern region of Murcia reached the highest temperature in AEMET's main network last month, reaching 44.2C on July 23.

The relentless heat and scarce rainfall created ideal conditions for wildfires that scarred swathes of Spain, including a huge blaze just dozens of kilometres west of the capital Madrid.

The largest wildfire in Spain's recent history burned more than 50,000 hectares (123,500 acres), forced the evacuation of tens of thousands of people and sparked a national emergency. 

France's national weather agency, Météo-France, is warning about temperatures approaching 40C from Tuesday onward in southeastern France. 

Heatwave alerts were issued for the first time on record in May, when more than half the country recorded new monthly temperature highs. 

The heat intensified in June, a period during which at least 5,700 more deaths than usual were recorded, according to France's public health agency.

Météo-France said June 23 was the hottest day ever recorded in the country. Temperatures climbed as high as 44.3C in the southwest.

Two other heatwave episodes were recorded in July, amplifying a historic wildfire in southwestern France that forced 220,000 people to flee their homes in one of the continent's biggest evacuation efforts since the Second World War. 

Very dry conditions were observed in July across western and central European nations including France, Spain, Austria and Hungary but also the United Kingdom, Ireland and part of Iceland.

River flows were unusually low with the Seine, Rhine and Danube particularly affected. Transport, irrigation and energy production has been affected in several European countries.

These hot and dry conditions were also ideal for fires and scientists say the frequency of extreme fire-prone weather in Europe is increasing with climate change.

Copernicus also said the world's oceans hit record-high temperatures for a second straight month in July, driven by marine heatwaves around Europe and a powerful El Nino taking shape in the Pacific.

Global average sea surface temperatures in July were 20.96C, beating the previous record of 2023.

Copernicus director Carlo Buontempo said parts of the Mediterranean and Atlantic were unusually warm but the developing El Nino 'is probably the driving force' behind the record sea temperatures.

'We are now facing a very large El Nino - possibly unprecedented in terms of amplitude. It is clear that the contribution coming from the tropical Pacific becomes quite important,' the climate scientist told reporters on August 5.

El Nino is the warm phase of a natural climate cycle that temporarily raises ocean temperatures in the tropical Pacific and can influence weather extremes like drought and floods around the world.

It also adds heat to a planet already warmed from burning fossil fuels.

El Nino events typically peak at the end of a year before heat is released from the ocean into the atmosphere, pushing up global temperatures.

The last El Nino helped make 2023 and 2024 the second- and first-hottest years on record, respectively.

Mr Buontempo said scientists expect a new record for global average temperatures later this year or early 2027.

Globally, last month was the joint second-warmest July on record with an average surface air temperature 1.47C above the 1850-1900 pre-industrial benchmark, Copernicus said.

The last 11 years have been the hottest on record and 'we have not seen a climate that warm during our lifetime, and very possibly our civilisation,' Buontempo said.

'And the main driver for this warming - as we know - are the greenhouse gases,' he said.

Oceans absorb most of the excess heat caused by humanity's carbon emissions and therefore play a key role in regulating the climate.

Hotter seas can have damaging knock-on effects on the planet, fuelling stronger storms and rainfall and bleaching coral reefs.

Copernicus takes measurements using billions of satellite and weather readings, both on land and at sea, and its data extends back to 1940.