At age 8, Greta Thunberg, who lives in Stockholm, Sweden, learned about climate change. By age 11, she had fallen into a deep depression because of the lack of global action to solve the climate crisis. A doctor diagnosed her with obsessive compulsive disorder (OCD), selective mute syndrome, and Asperger’s syndrome, which means she is on the autism spectrum. Being autistic, she said in a TEDx talk, means she sees the world in “black and white.” And for her, acting on climate change is a black and white issue: “We must stop carbon emissions from fossil fuels. We have to change.”

Beginning at age 15, Thunberg started channeling her frustration into being a dedicated climate activist, sitting in front of Sweden’s National Legislature every day, during school hours, demanding the Swedish government reduce carbon emissions by at least 15 percent each year. Thunberg decided on such a radical move because “no one in the media is talking about climate change; and you would think they would talk about nothing else.”

Thunberg — who was inspired by the teen activists at Parkland in Florida skipping school to protest gun violence — has herself inspired a global movement of student-led climate protests. Last year, an estimated 20,000 school children held climate strikes in 270 cities. On March 15, the biggest global protest yet occurred — with an estimated one million students skipping school to march for climate action. Organizers estimated there were some 2,000 strikes in 125 countries.

The UK Student Climate Network, which organized protests in London, released a manifesto that clearly relays the protesters’ frustration and anxiety about the future:

“We’ve joined a movement that’s spreading rapidly across the world, catalyzed by the actions of one individual in taking a stand in August last year. Greta Thunberg may have been the spark, but we’re the wildfire and we’re fueled by the necessity for action.

The climate is in crisis. We will be facing ecological catastrophe and climate breakdown in the very near future if those in power don’t act urgently and radically to change our trajectory. Scientists have been giving increasingly dire warnings about the state of our planet for years, with the urgency and severity of their message escalating in recent times. It’s abundantly clear: change is needed, and it’s needed now!”

According to CBS News, protesting school children were united in their demand for a rapid transition to 100 percent renewable energy.

In the U.S., the strike was organized by Youth Climate Strike, a coalition led by Isra Hirsi, a 16-year-old sophmore from Minneapolis, Minnesota, and Haven Coleman, 12-year-old 7th grader from Denver, Colorado. In San Francisco, hundreds of students marched from House Speaker Nancy Pelosi’s office to Senator Dianne Feinstein’s office, demanding action. And in St. Paul, Minnesota, 1,000 students stood in front of the state Capitol chanting: “Stop denying the Earth is dying.”

Protests also occurred on March 15 across Europe, South America, Asia, and Africa. In Berlin, Germany, an estimated 20,000 student protestors waved signs such as “‘March now or swim later’ and ‘Climate Protection Report Card: F’” on their march towards German Chancellor Angela Merkel’s office. And in New Delhi, school children protested inaction on climate change as well as poor air quality, which causes an estimated 4.2 million premature deaths worldwide annually.

A recent Pew survey found that Generation Z, now aged 13-21, is equally as focused on climate change as the Millennial generation, now 22-37 years old. Some 54 percent of Gen Z sees climate change as being driven by human activity, while 56 percent of Millennials think the same. These numbers are considerably higher than for Gen Xers, Baby Boomers, or the Silent Generation.

The United Nations Secretary General António Guterres wrote an op-ed supporting the student protesters:

“These school children have grasped something that seems to elude many of their elders: we are in a race for our lives, and we are losing. The window of opportunity is closing – we no longer have the luxury of time, and climate delay is almost as dangerous as climate denial.

My generation has failed to respond properly to the dramatic challenge of climate change. This is deeply felt by young people. No wonder they are angry.”

Guterres said the “commitment and activism” shown by these students gives him hope the world’s leaders will shift course in time but it’s important to keep up the pressure. A recent United Nations report found that dramatically reducing emissions over the next 11 years is absolutely critical.