TORONTO -- As thousands of environmental activists march Friday in the Global Climate Strike, among them are likely to be scores of children afraid for their future.

Some school boards across the country are even exempting students from academic penalty to participate. But the presence of pre-teens and adolescents raises the question: Should children be a key player in environmental movements, or is all the talk of environmental ruin bad for them?

Early research suggests that climate anxiety or “eco-anxiety” is very real. One survey in the U.K. showed that half of children between the ages of seven and 11 worry about climate change. Other reports suggest kids are more worried about climate change than their own homework. In 2017, the American Psychological Association released a report detailing early research into the mental health effects of natural disasters and climate change. While that research is still fairly new, the evidence supporting climate change mounts every year. In June, a report out of Australia even suggested human civilization could end by 2050.

“There’s so much grim news out there and it feels pretty hopeless,” said registered psychologist Christine Korol, the director of the Vancouver Anxiety Centre. Korol treats both adults and children, many of whom have expressed eco-anxiety, she told CTVNews.ca. “The reactions are anywhere from denial to ‘We’re all going to die,’ and sometimes not much in between.”

Children and adolescents are becoming the major forces in activism in recent years, from the teenage survivors of the Parkland, Fla., high school shooting to 16-year-old Swedish environmental activist Greta Thunberg, who gave an emotional speech at the UN climate change summit earlier this week. Some responded online with worry and criticism that kids could become anxiety-ridden if involved in activism and exposed to so much fear. The issue has even spilled over into popular television storylines. In an episode of HBO’s Big Little Lies, Laura Dern’s character rails at her daughter’s teacher and school principal after the girl passes out during a climate change lesson.

But some experts suggest there may be some benefit to eco-anxiety -- as long as there’s not too much of it.

“Too much anxiety paralyzes you,” said Korol, relating the issue to the Yerkes–Dodson law that suggests stress can increase motivation. For many of the eco-anxious, encouraging engagement and participation in climate action may actually be helpful, she said, but so can turning down the TV.

That’s because hope is a key factor. “It’s important to counteract the nihilism and the hopelessness that people feel,” she said. “Hopelessness is the big enemy of solving any problem, including climate change. When we’re talking about children, we need to give them hope.”

Even in some communities that have been directly impacted by natural disaster, there are positive findings in response to eco-anxiety. When she looked into the mental health effects of intensified flooding in New Brunswick, Julia Woodhall-Melnik, the principle investigator with the University of New Brunswick’s Lab for Housing and Mental Health, found that even some of the negative effects such as anxiety and uncertainty were counteracted by hope and community building.

“I think when it becomes bad is when youth are thinking ‘Let’s do something about this now’ and nothing happens,” she said. “When there’s anxiety and feelings of helplessness I don’t think that that’s productive for anyone.”

For Korol, easing child eco-anxiety to the “right level” is important simply because there’s no other option. Children will have to face climate change eventually.

“There’s really no choice,” she said. “How you talk to kids about it can help them get that right level of anxiety about it. We need to teach kids to be engaged politically and to make sure they assert their right to have a say about the kind of planet they want to live on. That being passive let’s other people make the decisions.”