The very grownup reason your kids don’t want to go to school today.

While here at Startups for Grownups we spend a lot of our time spreading the message that you’re never too old, today we’re celebrating one female whose mantra is you’re never too young – and she’s making a global impact.

If you have a school-aged kid, chances are they – or some of their student colleagues – are not at school today. And the reason is Greta Thunberg.

Greta Thunberg is a 15-year old Swedish student who has started a global movement to pressure governments to take action on climate change.

Thunberg is the voice of millions of students world-wide who today, instead of hitting the books, will be gathering in protest at their relevant parliaments.

According Greta Thunberg, the inaction of grownups has left them no choice.

Today there are expected to be in excess of 55 separate protests around Australia attended by about 40,000 students as part of the School Strike 4 Climate campaign.

For Thunberg, it’ll be just another Friday. This young disruptor has been boycotting Fridays since for the past 42 school weeks.

Last year, she came to the world’s attention when she addressed a UN conference on climate in Poland, with a blistering speech to adults that pulled no punches – you have let us down, now we must take action.

Despite her protest and busy activist’s schedule, Greta Thunberg says her grades have not suffered and her school has been very supportive.

Aussie kids planning to strike today might not have the same experience, with some schools warning of harsh consequences for truancy on account of the strike.

NSW Labor leader Michael Daley, however, said in a National Press Club address this week that he supported the student strike.

"They do have a democratic right of assembly, they do have a right to protest."

But, says Greta Thunberg, talk is cheap. "Unless we start treating the crisis like a crisis we don’t stand a chance,” she has said.

You said it, Greta, and we’re right behind you!