Friday at COP26 was officially designated youth and public engagement day, and at the summit young climate leaders joined negotiators, officials and ministers.

The day’s events focused on harnessing the expertise of young people and putting their views directly to the negotiators and officials working to agree on global action on climate change.

COP26 President Alok Sharma said: “The voices of young people must be heard and reflected in these negotiations here at COP. The actions and scrutiny of young people are key to us keeping 1.5 alive and creating a net-zero future.

“I am also aware of the fear and anxiety many of them feel about the future of the planet, including my own children.”

But attention shifted away from the official presentations onto the streets of Glasgow on Friday, where thousands of young activists joined Greta Thunberg’s Fridays for Future protest.

Speaking to the crowd after a march through the city, the 18-year-old Thunberg in defiant mood, described COP26 as a “a global north greenwash festival, a two-week-long celebration of business as usual.”

Taking aim at the world’s most powerful political and business leaders in the richest countries, Thunberg accused them of wilfully avoiding actions to meet the climate emergency.

“Many are asking what it’ll take for people in power to wake up. But let’s be clear – they’re already awake. They know exactly what they’re doing. They know exactly what priceless values they’re sacrificing to maintain business as usual.”

Thunberg, who has become the face of global youth climate activism, said the media was culpable, for not holding “the people in power responsible for their action and inaction, as they continue to expand fossil fuel infrastructure, opening up new coal mines, new coal power plants, granting new oil licences, – still refusing to do the bare minimum like delivering on the long promised climate finance for loss and damage to the most vulnerable and least responsible countries. This is shameful.”

Young activists from Wales were there too, to hear Thunberg and get their own voices heard.

17-year-old Poppy Stowell-Evans, Chair of Youth Climate Wales, who was at the demonstration, told BBC Wales:

“It should make a difference when that many thousands of young people join together. If that doesn’t provide the incentive for world leaders to act then I don’t know what will. We’re in a stage of make or break.”

Colleague Molly Hucker said: “Here we see real climate leadership on the streets of Glasgow. This is where the action is. Young people are showing climate leadership, and if the leaders in positions of power can’t, then they should step aside and let those who can.”

Meanwhile, the Welsh Government’s Minister for Climate Change, Julie James, took time away from COP to visit the UK’s first large-scale, high-temperature tidal river heat pump in Clydebank –  part of a £250m regeneration project which will deliver more than 5,000 tonnes of CO2 reduction per year.

The system will provide affordable low carbon heating and hot water to homes, businesses and a new hospital across the 23-hectare site.

The Queen’s Quay heating system uses pioneering heat pump technology to extract cold water from the River Clyde, with industrial heat pumps using ammonia as a refrigerant to increase the temperature of the river water from 6-12°C, up to 80°C. The hot water is then supplied by a pipe network to heat residential and commercial buildings.

Speaking about her visit, the minister said the project was an example that Wales could and should follow:

“It’s really impressive. This could be the answer to the prayers of many a Welsh city looking for district heating networks run at low cost, in order to green all their infrastructure and their energy.

“It’s easy to think that the climate change problem we face is so huge that we just cannot solve it, and then you see a project like this, run by people who had some fith and who put their money where their mouth is, and you can see that the solutions are within our grasp.”

On Saturday the COP26 theme is nature and land-use, though attention may again shift away from the summit itself. Tens of thousands are expected to march in Glasgow once more as rallies across the world take place to coincide with the climate summit.