If we're looking for an example of a climate terrorist who hurts the cause more than anything else, in Belgium, it has to be Wouter Mouton.
Member of Extinction Rebellion, a terrorist organization funded by CEF (Climate Emergency Fund). CEF being being brought to life by money of the daughter of a petroleum industrialist. Money specifically used to support other eco terrorist organisations. Take that as you will.
Mouton has been notorious for glueing and chaining himself on various objects (famous paintings, roads, goalposts,...) and disrupting sports events (soccer, cycling,...). He claims that's what will bring attention to the cause. In reality, he's creating hatred towards anyone who's speaking out about climate change.
His last stunt was causing cyclists to fall during a broadcasted world tour criterium. Because hurting people who have trained their whole life for a sport they're good at is the ideal way to get to think about climate change according to this insane asshole.
If you really want to do a functional extreme climate action that's in line with your cause, take it to the polluters and the lawmakers that are causing/enabling our grounds and air to be poisoned. But you NEVER put your hands on anyone or anything who isn't directly involved. That's the difference between fighting for what's right and a terrorist.