Initial estimates suggest that as many as 10,000 students took part in the demonstrations across Switzerland, but this number is yet to be confirmed.
Young people have been protesting in Aarau, Basel, Baden, Zurich, Lausanne, Solothurn, Lucerne and Zug.
More than 8,000 students are said to have taken to the streets in Lausanne alone, according to organisers of the strikes.
The protests kicked off in Solothurn this morning at around 8am, followed by Zurich at 9:30am.
Last year, in December, some 1,000 students in Bern, Zurich, Basel and St Gallen protested after revisions to the Swiss C02 law were rejected.
True to Swiss form, the official rules of engagement were said to include respecting public transport.
You can see a video of the students protesting below. Or, you can follow the protests on Twitter by using the #klimastreik hashtag.
— Memi Beltrame (@bratwurstkomet) January 18, 2019
The next set of protests have already been planned for February 2nd.
The students were inspired by Greta Thunberg, a 16-year-old Swede who refused to attend school on Fridays until the Swedish government reduced its carbon emissions as required by the Paris Agreement.
They say they are not affiliated to any party or organisation.
“We realised that politicians are not reacting to the climate crisis and are not protecting the future of our generation,” reads the group's “About Us” section on the official website.
Thunberg has inspired other young people all over the world to also skip school, with strikes occurring in Australia, Austria, Belgium, Canada, Germany, Finland, Denmark, Japan, Switzerland and more.
Thunberg, who will be attending the World Economic Forum (WEF) in Davos this year, accused world leaders of acting like “irresponsible children” in a speech at the climate summit in Poland (COP24).
She is still protesting, as can be seen from her Tweet this morning.