An estimated 12,500 students walked out of their classrooms in Brussels, Belgium on Thursday to join the country's second youth-led climate march in the past week, demanding that government leaders from across Europe take bold action to help stem the global climate crisis.

Carrying signs reading "Act now before it's too late," "The planet needs you to give a damn," and "I'm sure the dinosaurs thought they had time, too," young people at the Marche Pour le Climat chanted, "We want change!" as they marched through the city in the rain.

"It's great to see the number of people present here today," march organizer Anuna De Wever told the Brussels Times. "It's an incredible signal. This cannot be ignored."

The "climate strike" movement by student in Brussels is part of a wide global campaign and just the latest sign that young people are increasingly taking the lead in demanding climate action—and refusing to abide by the status quo—amid deeply troubling reports that governments are running out of time to curb fossil fuel emissions.

The turnout was significantly larger than the demonstration students held last week, when about 3,000 young Belgians expressed anger over their Parliament's refusal to sign an agreement at the recent COP24 climate conference, calling for countries to accelerate their efforts to reduce carbon emissions. Young people from Uganda, the U.S., New Zealand, Colombia, and other countries also staged protests last week.

Dozens more school strikes are planned for Friday as well, with German students planning more than 40 protests.

The Intergovernmental Panel on Climate Change's (IPCC) report last October, which said only 12 years remain for governments to keep the warming of the globe under 1.5 degrees Celsius (or 2.7 degrees Fahrenheit) shook climate activists across the globe, leading Swedish teenager Greta Thunberg to speak out at COP24 and Australian students to stage their own climate strike in November.

On Twitter, supporters of the Belgian walkout praised the students for their leadership: