It's part of a global rally calling for action but schools are not happy.
The movement was started by a pupil in Sweden last year, but some teachers say it's simply bunking off lessons on a school day.
The rally is being held outside County Hall in Exeter.
Caspar Hughes has a daughter at a school in Exeter and was told her absence couldn't be authorised.
This is the reply Mr Hughes sent to the headteacher:
Dear Headmistress, Thanks for your reply. ********* will be striking on Friday outside County Hall, she is left with little choice as our generation has failed to keep her future secure. None of the petitions that have been signed or letters that have been written have worked. Last year global emission were higher than ever before. Our politicians are not dealing with the issues of climate change in a proportionate manner. They’ve failed. In the last twenty five years we’ve emitted more CO2 than in the entire time humans have existed on the planet before. This unprecedented level of emissions has pushed our environment into an incredibly precarious position. The last time the was as much CO2 in the atmosphere as currently the temperature was 3-4°higher. A serious problem that we face is the breaching of tipping points. These tipping point breaches will move the collapsing climate from a linear change to abrupt change. As happens when the climate jumps from one state to another. The recent science is showing that the feedback loops are starting to accelerating at a non linear pace. The collapsing climate crisis has sped up to such a pace that some internationally renowned scientists are discussing climate collapse within the next five years. If we don’t change course very quickly cultural collapse is virtually inevitable, the likelihood of this happening before 2060 is becoming increasingly probable. Is the education that you are giving our children teaching them about the current climate breakdown sufficiently? Does your curriculum include teaching your students how to mitigate the worst case scenarios? Are you teaching them how to live low carbon lifestyles? Are you changing the schools systems to reduce the schools carbon footprint? Are you divesting the school and trust from fossil fuel investments? If not are you teaching them about the climate crisis are you teaching them how to adapt to a world that will be 4-8° higher than our current temperature? Yours Faithfully Caspar Hughes