Also, emissions are already falling, and air quality has been improving since 2008/09 (see this report for TfL). By 2030, Khan’s scheme will be making no difference at all.
Nobody wants to condemn people to living with unsafe levels of pollution, but the evidence shows that this is not the case outside central London, other than along major routes at hotspot junctions.
The major source of pollution along those routes are buses and heavier commercial vehicles. We don’t oppose the changes planned for those vehicles. We just don’t think motorcyclists, older and lower paid drivers and those who need their vehicles for work, should have to pay £12.50, every time they need to drive.