The youth-led protests were the latest in a series of international demonstrations known as the Global Climate Strike.
In Warsaw, demonstrators demanded "climate justice" and urgent steps to end the use of fossil fuels such as coal, Poland's PAP news agency reported.
They also urged a greater focus on renewable energy and policies to reduce greenhouse gas emissions.
Environmentalists have appealed to teachers to allow students to skip classes to join the climate strike. Photo: PAP/Radek Pietruszka
Protesters gathered at Na Rozdrożu Square in central Warsaw, from where they set off on a march through the city’s downtown streets past buildings including the houses of parliament.
They carried banners and chanted slogans such as "No to coal" and "Climate solidarity,” the Polish state news agency reported.
It also said the protest caused huge traffic jams in parts of the city.
(gs/pk)
Source: PAP