A petition calling on the Belgian government to strengthen its climate policy has already been signed by 100,000 people.
Meanwhile, thousands of Belgian students will again be skipping class for the sixth week in a row.
They're also demanding a better climate policy.
Kevin Ozebek has more from Brussels:

Israel launches airstrikes on south Lebanon
Voting ends in first phase of election in India's Bihar
Britain's Prince William calls for optimism on environment at EarthShot Prize event
Afghanistan and Pakistan return to Istanbul for more peace talks
Groping of Mexico's president puts violence against women in spotlight