The day had barely begun when roughly 100 students marched out the front gates of East Career Technical Academy on Friday morning. Some clutched signs — all made from recyclable products — with handwritten messages:

“Planet over profit”

“Protect our climate, water and health”

“Our house is in fire — it’s getting hot in here”

They gathered near the school’s flagpole, the spot where students and administrators had agreed they could stage their climate walkout. Though their stand was brief — they had just 15 minutes between their first- and second-period classes — the students joined hundreds of thousands of young people across the Silver State and around the world in a Global Climate Strike to call for immediate action to combat climate change.

More than 4,500 events in 139 countries were slated for Friday and in the coming week. The youth-led movement comes days before the United Nations holds a climate action summit in New York City. Greta Thunberg, a 16-year-old climate activist from Sweden, made headlines for sailing 14 days across the Atlantic Ocean to address the summit.

Young people across the globe have been among the most vocal in calling for urgent action, particularly in the wake of a U.N. report that determined that the world has 12 years to act to mitigate the effects of climate change. Specifically, U.N. climate scientists determined that in order to limit global warming to 2.7 degrees above pre-industrial temperatures, the world will have to cut greenhouse gas emissions by about half by 2030 — or 12 years from when the report was released in 2018 — and to around net zero by mid-century.

“The reality of all of this is that this is something that affects us all as youth, and we need to stand up and unify as a group to reach a common goal, which is essentially saving the planet,” Jaedon Villasista, a senior at East Career Technical Academy (ECTA), told the group of students who had walked out. “We can only do that together.”

For Jackie Chiakulas, an organizer with the environmental group 350 Nevada, the global climate strike has been about sending a message to public institutions and elected officials.

“Locally, we’ve been trying to get in touch with the school district and get as much teacher and staff support .. to show how many students care and want to be heard on this issue. For next year, especially before the election, [officials] know this wave is coming,” Chiakulas said in an interview on Friday morning.

But student organizers said they had a difficult time coordinating the walkouts with Clark County School District.

“I was able to email the superintendent, Jesus Jara, who acknowledged and said he’d get back to me but never ended up getting back to us,” Chiakulas said. “So we resorted to digitally submitting comments to the board of trustees and just got a general email back saying they received our email... they didn’t really come out in support.”

CCSD gave administrators and principals discretion as to whether to allow students to distribute flyers, organize and strike.

“We encourage students to have conversations about issues significant to them in the appropriate educational settings,” the district said in a statement. “If students approach school administrators about organizing events, principals will assess the impact to their particular schools and take necessary steps to support students as deemed appropriate, while ensuring the safety and well-being of students.”

ECTA Principal Darlin Delgado said she wanted her students to be able to express themselves as long as they did so safely without a huge interruption to the school day. She also encouraged students to do research on the topic. Several students stayed after school Wednesday to make posters and prepare for the walkout, she said.

“Before participating in things, they have to be well-informed,” she said.

Palo Verde student Dexter Lim was unsure whether the administration at his high school would allow students to participate in the Friday strike.

“I was approached by administration requesting I stop pamphleting,” Lim said. “However, this morning administration was supportive and allowed the strike to continue as planned.”

Lim said that students at his school did not receive detention or other punitive action for walking out on Friday.

U.S. school districts’ reactions to the climate strike have varied, with some discouraging it. Some districts have been more supportive; the New York City Department of Education provided guidelines for all of its public school students to have their absences excused when participating in walkout protests.

.@NYCschools will excuse absences of students participating in the #ClimateStrike on Friday 9/20. Students will need parental consent. Younger students can only leave school with a parent. https://t.co/hcBO1Cnb3m — NYC Public Schools (@NYCSchools) September 12, 2019

“The [New York] school district doing that sends a message to students that they care and that they support them. We would have loved to see Clark County do the same for students here,” said Matt Piper, organizer with Sunrise Movement Las Vegas.

When all was said and done, students from at least seven schools in the Las Vegas Valley turned out for the climate change strike in hopes of making their voices heard.

Friday afternoon at Advanced Technologies Academy, teachers and administration stood on the sidelines as about 150 students congregated in front of the main office before school let out.

A-Tech student Ariana Boorboor, who organized the walkout, stood on a bench and spoke into a megaphone to address the crowd. She urged students to register to vote as soon as they turn 18.

“We need a government that will fight for our rights. All you juniors and seniors, get ready to make some real change, because it is coming soon,” BoorBoor said.

Students were invited to step up and share with the crowd the reasons they were striking. Many cited loss of wildlife habitat and natural disasters such as droughts and wildfires.

In Reno, a group of about 18-20 people attended the Climate Strike at Damonte Ranch High School. Clyde Vanaken,15, learned about the Climate Strike on the radio this morning.

“If we keep going how we are, we’re not going to have a life,” he said.

On Friday evening, people of all ages came to support the Climate Strike in downtown Reno near a giant steel sign that reads “BELIEVE.” Organizers estimated almost 700 people attended.

Among the crowd were numerous employees from the outdoor apparel company Patagonia, who were given half the day off to be able to attend the event.

Patagonia employee Katie Trent, 27, joined the demonstration with some friends.

“So many people say they don’t want to have kids anymore because they’re worried what the world will be like in 15-20 years,” she said. “I definitely think it is more of a youth issue. Because they are the ones who will have to deal with it.”