Intelligent life (at least, life which can build civilisation) has not experienced extinction events on earth before. If the current extinction event caused by

Intelligent life (at least, life which can build civilisation) has not experienced extinction events on earth before. If the current extinction event caused by climate change eventually includes the extinction of humans, which is becoming increasingly likely, it will be impossible for any future intelligent lifeforms to build civilisations. We have already extracted all of the easily-obtained resources that more primitive civilisations would require in order to develop.