By CNN's Isabelle Gerretsen
Eleven-year-old Atlas Sarrafoglu has organized a climate strike in a park in Istanbul, Turkey, CNN's Murat Baykara reports.
"School can wait but climate change won’t. Due to climate change, floods or even tornadoes are more common now. Due to heat there is no water left in the dams. This is what you have created," Sarrafoglu tells the crowd.
You burned the coal that causes climate change. It was you adults who cut the trees and destroy our forests," he says.
By CNN's Tom Page
In Madrid, Spain marchers say "not another degree"...
...while in Barcelona here's the scene on the ground...
...and on the streets of Pamplona, home of the running of the bulls, the refrain "There's no Planet B" joins another message: "We want you to panic."
By CNN's Tom Page
A stark message from a Francophone protester.
By CNN's Tom Page
Over 2,000 events are planned across 123 countries today. Every continent is involved -- including Antarctica. It's nearly impossible to keep on top of every march here on this live blog, but we're doing our best!
Take a look at the map below to see which countries are taking part. We'll endeavor to keep it up to date throughout the day.
By CNN's Mark Tutton
Greta Thunberg, the 16-year-old climate activist who has inspired student strikes worldwide, joins protesters in Stockholm, Sweden, where she has been staging weekly sit-ins outside parliament.
She urges other young protesters: “I think we should continue until they do something. This is not a one-time thing."
“We are not just protesting to let them see that we care, we are protesting until they do something. We are going to put pressure on them and just keep on going," she tells CNN’s Atika Shubert, adding that we have yet to see meaningful action on tackling climate change.
“The most important thing to look at is if emissions are increasing or reducing -- and they’re increasing.”
Watch this profile of Greta Thunberg.
By CNN's Isabelle Gerretsen
Hundreds of students gather outside the Houses of Parliament in London, waving banners reading "system change not climate change" and "make earth cool again."
Sixteen-year-old Alice Smith tells CNN she doesn't understand anyone who isn't scared of climate change.
"At the end of the day it doesn’t matter your race, your gender, your sexuality -- we’re all going to be affected by climate change. And we have 12 years left before the point of no return," she says.
By CNN's Tom Page
16-year-old Swedish climate activist Greta Thunberg shares a photo of incredible scenes in Sydney earlier today, when students marched and filled Town Hall Square.
Earlier this week, Australian Home Affairs secretary Mike Pezzullo named climate change among seven “gathering storms” he sees for national security in the coming decade.
By CNN's Isabelle Gerretsen
Since September, 10-year-old Lilly Platt from the Netherlands has skipped school every Friday to protest the Dutch government's failure to curb emissions.
The Netherlands announced this week that it would implement a carbon tax for companies after judges ordered the government to accelerate carbon emissions cuts last year.
"Climate change will affect us very much in Holland because (the country) is below sea level. (Extreme) weather is affecting farmers' crops already," Platt tells CNN.
Platt is joining other strikers outside the Dutch parliament today.
By CNN's Tom Page
A flavor of scenes on the ground in Vienna, Austria, where thousands are marching through the city.