Emma Lim, an 18-year-old student at McGill University in Montreal, created the #NoFutureNoChildren movement in response to the perceived lackluster efforts from Canadian leaders on the issue.
"I have always, always wanted to be a mom, for as long as I can remember," Lim told Insider. "But I will not bring a child into a world where they will not be safe. I would like to see the government develop a comprehensive plan to stay below 1.5 degrees of warming."
As of Thursday, more than 1,400 young people had signed on.
"I am taking the pledge because I deserve to live in a planet that is taken care of, a planet that is cherished," wrote Iffat Hasan, 18, of Ottawa, Ontario.
Jacob Diercks, 18, of Germany, signed on, saying he lived near the North Sea, which has warmed in recent years. He said farmers there have lost crops to floods and hot weather.
"I see it as irresponsible to bring children into such dangers," he wrote. "Our government is doing too little to protect the climate and thus our region."
Multiple reports have warned of a catastrophic scenario if steps are not taken to reduce carbon emissions, pollutants and other types of human behavior responsible for warmer temperatures and unpredictable weather patterns.
Lim said climate change has been a "fact of life" for her generation. In addition to addressing the problem, she's called for a plan to help those affected by climate change, such as people losing their jobs in the agricultural, oil and gas industries.
"I launched the pledge because I wanted other people to understand how the fear of climate is so unquestioned in my generation," she said. "It's something everybody feels. Where in my parent's or grandparent's generation, believing in climate change is often a matter of opinion and not survival."
She added that many young people have believed their governments will fix things, but "that trust in your leaders erodes over time."
Teens around the world have taken a more active role in bringing attention to the issue.
Youth climate activist and Swedish teen Greta Thunberg, 16, testified in front of Congress this week about the importance of climate-change activism. She started skipping school on Fridays to stand outside of her country's parliament to protest what she called inaction by government leaders.
Rep. Alexandria Ocasio-Cortez has made climate change a centerpiece issue and has pushed for the passage of her ambitious Green New Deal, which calls for a dramatic reduction in emissions, along with universal health care, affordable housing, and "economic security."