Teen climate activist Greta Thunberg told tens of thousands of environmental protesters in Britain on Friday that "activism works" — the day after plans for a third runway at London's Heathrow airport suffered a setback.

The Swedish eco warrior visited Bristol, in southwestern England, for a so-called climate strike march attended by crowds of students skipping school in protest at perceived global inaction over climate change.

The 17-year-old has inspired millions of young people around the world by spearheading a movement since 2018 to demonstrate on Fridays in frustration at government efforts to tackle the issue.

"World leaders are behaving like children, so it falls on us to be the adults in the room," she said at a rally in Bristol.

"We must continue and we have to be patient," Thunberg, kitted out in her trademark yellow anorak as rain steadily fell, added.

"If enough people are pushing for change, then change will come."

Britain's Court of Appeal on Thursday ruled in favour of environmental campaigners who oppose the building of a third runway at London's Heathrow airport, Europe's busiest.

The court said the UK government — which approved the Heathrow extension in 2018 after years of delays — had failed to take into account commitments to the Paris Agreement on limiting global warming.

However, Thunberg cited the rejection by local councillors earlier this month of plans to expand Bristol Airport — which it had said would boost passenger capacity by two million a year — in her rallying speech to activists.

– Making a difference –

"This is far from enough, but it shows that it does actually make a difference.

"Activism works. So I'm telling you to act."

Police said there were more than 20,000 people at the protest, while organisers claimed the number was closer to 30,000.

The city, which has a centuries-long reputation for its political radicalism, has embraced the youth climate protests, with Greta calling the local movement "very strong."

She chose to visit after plans for a London rally were shelved due to the mushrooming size of the expected crowd.

After her address, the Swedish teenager led the crowds as they marched through Bristol city centre accompanied by a Samba band.

The rally's young attendees, many accompanied by parents, carried signs reading "don't be a fossil fool", "we're going to need a bigger boat" and "save earth don't breed".

The more adventurous had climbed traffic lights to get a better view, while others watched from the roof of the city's main cathedral.

"We'll probably get a detention but this is more important," protester Aisha Benamal, 14, told AFP.

Moscow winter 'warmest since records began': weather service
Moscow (AFP) Feb 29, 2020 –

Russia's capital Moscow, which for the past months has largely been deprived of its traditional seasonal covering of snow, has seen its warmest winter since records began, the state weather service said on Saturday.

The head of Russia's forecasting centre Roman Vilfand told the TASS news agency that the average temperature in Russia from December to February has been some 2.5 degrees Celsius (4.5 Fahrenheit) warmer than the previous record of minus 2.8 degrees seen in the winter of 1960-1961.

He said such differences between records were extremely rare. Records began 140 years ago in Russia.

"I am sure that we are not going to see such a warm winter again for a long time," he said. He added that the winter record for Russia as a whole would also likely be beaten but said the data was still being compiled.

2019 was also the hottest year ever registered in Russia. Muscovites of the elder generation fondly remember crisper and colder winters from decades back when the parks of the city were covered in plentiful snow.

The Kremlin acknowledges global warming, with President Vladimir Putin saying in December that the rate of warming for Russia was 2.5 percent higher than elsewhere on the planet.

But he cast doubt over whether global warming is of manmade origin and stated it could be blamed on cosmological processes. "Nobody knows the origins of global climate change," Putin said.