A lack of snow and an exceptionally high risk of accidents has forced the closure of many of France’s ski runs, with slopes icy and “as hard as concrete”, officials said on Wednesday.

A combination of extremely low night temperatures and scant snowfall is making conditions treacherous even for the most proficient skiers. Local authorities blame climate change, which is also causing glaciers to melt in the Alps.

There is little likelihood of “powdery” soft snow in the coming weeks, with temperatures set to fall further but no snow forecast.

Only four out of 56 runs are open at Saint-Lary-Soulan, a resort in the Pyrenees. Jean-Claude Dupla, the director, said: “We’ve had problematic winters before, but this time, there’s no snow, even on the higher slopes. This is the first time in 20 years that anyone remembers it being this bad.”

Marcellin Bernard, a ski instructor at Val-Thorens, Europe’s highest ski resort, said lower resorts were the worst affected. “It’s still pretty good here thanks to the altitude. We’ve got the snow guns working at night, but resorts lower down like Les Menuires are having more problems. At Val-Thorens, the artificial snow makes it soft on top, but the underlying layer of natural snow is much harder than usual.”

Mr Bernard, 70, has no doubt that the cause is climate change. “I’ve observed glaciers shrinking and the snow cover moving higher over decades, and I’m certain that this phenomenon is accelerating.”

A study on the prospects for the ski industry over the next two decades, commissioned by local authorities in Isère, south-eastern France, concludes: “There will be less snow on average. It will fall less often and for shorter periods.”

The study says the only way to maintain France’s ski industry is to continue investing in artificial snow systems, but the costs are high and environmentalists are concerned about the depletion of water reserves.

Officials are urging skiers to exercise particular caution this year. Gilles Szekely, an instructor at the Chamrousse resort, said: “It freezes almost every night and in the morning it’s as hard as concrete. When you fall, you’re much more likely to break something.”

Gérard Colas, a doctor at the resort, said: “Our clinic’s full almost all day and I’m treating a lot of fractures. On ice, you can’t control your skis like you can on soft snow.’

David Lebor is not your typical German language teacher. He refuses to use textbooks. He doesn’t teach in a classroom setting, but prefers to take his students onto the streets. And, perhaps most surprising of all, he is British.

Yet the 42-year-old entrepreneur’s radical new approach to teaching languages is helping Germany deal with one of the biggest issues thrown up by the influx of more than 1m migrants in recent years: teaching them to speak German.

Armed with nothing more than a mobile phone app, Mr Lebor is sending young migrants out onto the streets of Berlin to learn German by talking to local people.

Nasratullah Sultani arrived in Germany three months ago after fleeing his native Afghanistan….

Five teenagers and a 39-year-old mother were killed in a stampede at an Italian nightclub early on Saturday after someone reportedly released pepper spray and caused a panic inside the crowded venue. 

The six people were crushed to death near the exit of the Blue Lantern disco in the central Italian town of Corinaldo, around 90 miles east of Florence. Another 53 people were injured, with 13 of them in serious condition, according to police. 

The teenagers – three girls and two boys – were all aged between 14 and 16. The mother was bringing her daughter to a rap concert at the club. 

Shortly before the stampede, at around 1am, concertgoers said their eyes began to sting. Italian media reported that someone in the crowd had fired pepper spray, either during a fight or as part of a robbery. 

“The cause may have been the dispersal of a stinging substance, the young people fled and trampled over each other. Sadly, six people died and dozens are injured,” the fire service said in a statement. 

The Blue Lantern appeared to be overcrowded, which may have contributed to the chaos, according to Matteo Salvini, the Italian interior minister. Local prosecutors said that the venue had sold 1,400 tickets were but its capacity was only about 870 people.

Mr Salvini vowed that authorities would prosecute whoever was responsible, saying they “transformed an evening of partying into tragedy” with their “nastiness, stupidity or greed”.

The crowds of young people had gathered to see Sfera Ebbasta, an Italian rapper, but the stampede took place shortly before he was due to take the stage. 

Mr Ebbasta wrote on Twitter that he was "deeply pained" by the tragedy, thanked rescuers and offered his "affection and support" to the families of the dead and the injured. 

The rapper said he didn’t want to "express judgment" on those responsible but added he wanted everyone to "to stop and think how dangerous and stupid it is to use pepper spray in a discotheque."

At the Vatican, Pope Francis bowed his head in silent prayer after he told some 30,000 pilgrims and tourists in St. Peter’s Square that he was praying "for the young people and the mamma" as well as for the many injured at the concert.

Doctors in the nearby city of Ancona said the most critically injured, all between 14 and 20 years old, had suffered cranial and chest traumas, while others had injuries on their arms or legs. The dead were reported to have suffered crushed skulls.

Video showed a low wall inside the club appearing to give way, sending a cascade of teenagers tumbling over it and falling on top of each other.

Sergio Mattarella, Italy’s president, demanded that a "full light be shone on what happened, ascertaining any responsibility and negligence."

Nearly 200 countries overcame political divisions late on Saturday to agree rules for implementing the 2015 Paris Agreement on climate change, but critics say it is not ambitious enough to prevent the dangerous effects of global warming.

Eleventh hour disagreements over carbon markets almost derailed negotiations and delayed a final agreement by a day.

In the end it took two weeks of talks in the Polish city of Katowice to turn the aim of the Paris accord – limiting global temperature rises to well below 2C – into a more detailed framework.

"It is not easy to find agreement on a deal so specific and technical. Through this package you have made a thousand little steps forward together. You can feel proud," Michal Kurtyka, the Polish president of the talks told delegates.

After he struck the gavel to signal agreement, ministers joined him on the stage, hugging and laughing in signs of relief after the marathon talks.

Even before negotiators convened, many expected the deal would not be as robust as needed. President Donald Trump has already announced his intention to pull his country – one of the world’s biggest emitters – out of the pact.

At the 11th hour, ministers managed to break a deadlock between Brazil and other countries over the accounting rules for the monitoring of carbon credits, deferring the bulk of that discussion to next year, but missing an opportunity to send a signal to businesses to speed up their actions.

Still, exhausted ministers managed to bridge a series of divides to produce a 156-page rulebook – which is broken down into themes such as how countries will report and monitor their national pledges to curb greenhouse gas emissions and update their emissions plans.

It allows flexibility for poorer nations, which claim they suffer greater impacts of rising temperatures triggered by more developed countries.

But richer nations have long rejected the idea of being legally liable for climate change.

As a result, several ministers conceded there was more work to be done but held out the framework as important progress.

"While some rulebook elements still need to be fleshed out, it is a foundation for strengthening the Paris Agreement and could help facilitate US re-entry into the Paris Agreement by a future presidential administration," said Alden Meyer of the Union of Concerned Scientists.

Some countries and green groups criticised the outcome for failing to urge increased ambitions on emissions cuts sufficiently to curb rising temperatures. Poorer nations vulnerable to climate change also wanted more clarity on how an already agreed $100 billion a year of climate finance by 2020 will be provided and on efforts to build on that amount further from the end of the decade.

A statement by António Guterres, UN Secretary-General, who left the talks on Thursday, stressed the need for more work.

"From now on, my five priorities will be: ambition, ambition, ambition, ambition and ambition," it said.

"And ambition must guide all member states as they prepare their (emissions cut plans) for 2020 to reverse the present trend in which climate change is still running faster than us."

A UN-commissioned report by the IPCC in October warned that keeping the Earth’s temperature rise to 1.5 degrees C would need "unprecedented changes" in every aspect of society.

Last week, Saudi Arabia, the Unites States, Russia and Kuwait refused to use the word "welcome" in association with the findings of the report.

The decision text now merely expresses gratitude for the work on the report, welcomes its timely completion and invites parties to use the information in it.

The Canadian government said 13 of its citizens have been detained in China since Canada arrested Huawei CFO Meng Wanzhou in Vancouver last month at the request of the US. Previously, only three of the detentions had been made known to the public.

The detainees include Michael Kovrig, a former Canadian diplomat; Michael Spavor, a Canadian businessman with dealings in North Korea; and Sarah McIver, a Canadian teacher who was arrested for "unlawfully working in China" and was subsequently released.

The publicised arrests of the three Canadians were widely seen as retaliation for Canada arresting Ms Meng, a move that infuriated Beijing. 

Canadian authorities did not disclose the identity of the other 10 detainees but said eight of them had been released from custody.

A government official told Canadian newspaper The Globe and Mail that about 200 Canadians are involved in different stages of legal proceedings in China for various alleged infractions.

The official added that the number of Canadians arrested has not fluctuated much over recent years. China’s Ministry of Justice said Friday that the arrests were in compliance with the law and gave no details on the detainees’ identities or charges.

Mr Kovrig and Mr Spavor remain in custody, facing accusations of harming China’s national security. China’s prosecutor general, Zhang Jun, said Thursday the pair “without a doubt” violated the law.

He said the investigation has been handled “strictly” according to the law and did not say when the two men might be charged.

Ms Meng has been released on a C$10 million (£5.9 million) bail and is living in one of her two Vancouver homes as she fights extradition to the US over alleged sanctions violations.      

Meanwhile, the US State Department issued travel advisory Thursday for Americans travelling in China to “exercise increased caution” due to “the arbitrary enforcement of local laws”, in the midst of heightened diplomatic tension between US and China over the arrest of Ms Meng.

The advisory informs US citizens about China’s “exit ban” practices that could keep its citizens remain in China for years. "US citizens may be detained without access to… consular services or information about their alleged crime," the advisory said.

In response to the travel advisory, China’s foreign ministry spokesman Lu Kang said Friday China welcomes foreigners including Americans. He said China safeguards their safety and legal rights, but expect visitors to abide by the law.