Nick Smith just killed 635 people.
That's the cost in human lives of his cowardly decision to extend the deadline to meet air-quality standards to 2020: 635 completely avoidable deaths - the very thing air quality standards are supposed to prevent. But to Smith, protecting the ability of polluters to make money by externalising their costs onto society takes precedence over protecting human life, and so he's backed the polluters and condemned those people to death. I wonder how he lives with himself. But he'll never know who has killed, never see their faces. It's anonymous murder by statistics - but murder just the same.
Air pollution kills 1,100 people a year. It is the government's job to prevent that. If Smith is unwilling to do that job, then he should resign. It is that simple.