Surely Man has been "contributing" to climate change since the dawn of time but it has accelerated since the Industrial Revolution.

"Selflessly giving up their time" eh? So that's OK to be selfishly disrupting the time of everyone else? I note one supposed protestor on a plane refusing to take his seat while sporting a mobile phone, was he live-streaming his actions like that other fool who was on the roof of another plane while he live-streamed his actions?

Didn't all that contribute to climate change far more than if they'd just stayed at home?

I think those protesters are really saying "Do as I say but I'm free to do as I do."