Six million people have taken to the streets over the past week, uniting across timezones, cultures and generations to demand urgent action on the escalating ecological emergency.

A fresh wave of climate strikes swept around the globe on Friday with an estimated 2 million people walking out of schools and workplaces.

Organisers say that during the week of protests – that began with a global climate strike last week – a total of 6 million people, from trade unionists to schoolchildren, have taken part in thousands of towns and cities.

“This week was a demonstration of the power of our movement,” said a spokesperson for the FridaysForFuture group which has helped coordinate the demonstrations. “People power is more powerful than the people in power. It was the biggest ever climate mobilisation, and it’s only the beginning. The momentum is on our side and we are not going anywhere.”

Facebook Twitter Pinterest A climate protester in Wellington. More than 3.5% of New Zealand’s population joined Friday’s demonstrations. Photograph: Hagen Hopkins/Getty Images

On Friday there were huge protests in Italy – where more than 1 million people were reported to have taken part – Spain, the Netherlands and New Zealand, where more than 3.5% of the country’s population joined the demonstrations.

Organisers said they were expecting more people to join as the day progressed. High turnouts were expected in Canada, where Greta Thunberg – who kickstarted the school strike movement with a solo protest in Sweden 12 months ago – was due to join demonstrators in Montreal.

May Boeve from 350.org, which has helped organise the demonstrations, said: “We will keep fighting until the politicians stop ignoring the science, and the fossil fuel companies are held responsible for their crimes against our future, as they should have been decades ago.”

Facebook Twitter Pinterest Students on a Fridays For Future march in Kolkata, India. Photograph: Ranita Roy/Reuters

The day of protests began in New Zealand, where an open letter was delivered to parliament on Friday morning calling on the government to declare a climate emergency – following the lead of numerous councils around the country.

“Our representatives need to show us meaningful and immediate action that safeguards our futures on this planet,” Raven Maeder, the School Strike 4 Climate national coordinator, said. “Nothing else will matter if we cannot look after the Earth for current and future generations. This is our home.”

Strikes and demonstrations followed in scores of other countries from Ghana to Samoa, the Philippines to Indonesia, South Korea to Taiwan.

In some countries, protesters have had to go to extraordinary lengths to express their message to resistant authorities or an indifferent public.

Facebook Twitter Pinterest A climate striker in Pushkin Square, Moscow, where protesters have found it ‘almost impossible’ to get permission for a mass demonstration

Makichyan Arshak has been staging a solo school strike in Pushkin Square, Moscow, for 29 weeks.

“In Moscow it is almost impossible to get permission for a mass demonstration so we protest in a queue. One person holds a poster for five minutes, then hands over to the next person who is waiting nearby. That way, we don’t have any problems because it is a series of solo strikes rather than a group gathering,” said the 25-year-old violinist, a graduate of the Moscow Conservatory.

Demonstrations also took place across South America, from Mexico City’s vast Zócalo square to the Plaza de Mayo in Buenos Aires.

On Bogotá’s high Andean plain, the environmental movement has faced a severe crackdown. In July, protesters across Colombia pleaded for an end to the violence that has resulted in numerous activists being killed, with the peace and development thinktank Indepaz putting the figure at 734 deaths in the first seven months of 2019.

Play Video 2:06 Greta Thunberg: the speeches that helped spark a climate movement – video

“We want to keep fracking out of our country and demand an immediate change towards decarbonisation,” said the activist Susana Muhamad, who was planning to march past the offices of the country’s largest petroleum company, Ecopetrol.

In Brazil, organisers said there were climate protests in São Paulo and at least nine other cities. In Rio de Janeiro, a group of university students rallied in the city centre bearing banners urging: “System change not climate change” and chanted: “What do we want? Climate justice. When do we want it? Now!”

Nayara Almeida, a 21-year-old student at the Federal University of Rio de Janeiro, said the group’s demands to the government included greater protection of the Amazon rainforest. “Our future is threatened and they are insensitive to that. We need politicians to make this a priority.”

The global climate strikers say their action is a sign of the growing awareness and anger of the severity and scale of the climate crisis among people around the world.

This week Thunberg excoriated world leaders at the UN for their “betrayal” of young people after the New York summit failed to deliver ambitious new commitments to address dangerous global heating.

The climate activist told governments: “You are still not mature enough to tell it like it is. You are failing us. But the young people are starting to understand your betrayal.”