Hundreds of high school students rallied against climate change in the center of Paris Friday for the second week in a row, although this time protesters were joined by a young Swedish campaigner who has risen to world-renown for going on strike, from her studies, to confront the perceived ineptitude of world leaders in the face of global warming.

Greta Thunberg, 16, who grabbed headlines after her stirring and damning speech at the United Nations' COP24 climate summit in Poland last year, joined roughly 300 people, mainly teens, who gathered in central Paris.

"In 50 years you will be dead, we won't be," was one of the choice chants rippling through the march. "Water is coming," and "There is no planet B," read some of the placards protesters held aloft at the gathering.

Although it was the second consecutive "Fridays for future" rally in France, numbers swelled on this occasion because of Thunberg's attendance.

"We kids shouldn't have to do this," Thunberg told a crowd gathered in a Paris square. "I wish that the adults would take their responsibility and do this instead but since no-ones' doing anything we have to," she told the rally.

"When I first started striking, I didn't really expect anything," she added. "I would never have imagined that it was going to be this big and I think it is incredible, it's a surprise every time I see someone else striking."

Thunberg started taking action against climate change in 2018. She decided to go on strike from school and would sit outside the Swedish parliament each day with a sign reading "school strike for the climate" until the Swedish general elections, after which she limited her action to Fridays.

She inspired young protesters the world over.

"The aim is to gather more and more people," Camille Beziat, a 23-year-old agricultural science student told EFE.

"I hope that more people come because Greta has come," she added.

The young protesters want the international community to abide by the Paris Agreement, a UN initiative to keep global temperatures to below 2C (35.6F) above preindustrial levels.

Thunberg was recently in Brussels, where she told European Union leaders that its policies to reduce carbon emissions by 2030 were not sufficient.

There were also protests in Germany, Belgium, the United Kingdom and Australia.