Emma Lim, 18, launched a climate change movement this week called “#No Future, No Children” that includes a website where other teens can take her pledge.

“I am giving up my chance of having a family because I will only have children if I know I can keep them safe,” she says on her website. “It breaks my heart, but I created this pledge because I know I am not alone. … We’ve read the science, and now we’re pleading with our government.”

By Thursday morning almost 1,000 kids had signed on.

Jacob Diercks, 18, lives near the North See in Meldorf, Germany. He signed onto the pledge, saying that in his lifetime he has seen the North Sea warm considerably. He said farmers there are in trouble due to flooding and summers so hot they burn the fields.