Sure, if we're taking 'existential threat' literally it's probably not in the sense that it won't end all human life on Earth. If we take it a little looser tho

Sure, if we're taking 'existential threat' literally it's probably not in the sense that it won't end all human life on Earth. If we take it a little looser though it is a big threat to modern civilization and that will be pretty difficult to restart just because we've mined so many of the easily available energy sources and resources.