The dates of any LEZ start are uncertain, but is likely to be spring 2017.
The cities will choose the costs, but it is likely that pre-Euro 6 vehicles will cost more. The costs in discussion are given below.
all can be affected, cars, vans, buses and lorries, but not electric vehicles
Not yet decided
Enforced through cameras and number plate recognition.
Not decided, but likely to be affected.
The penalty for not complying is at least 500 NOK (~ 55€). If the penalty isn't paid in the following 3 weeks the fine another 1000 NOK (~ 110€) apply.
Yes, there is a national scheme. There is a national law that allows for low emission zones in Norway.
The law sets the emissions standard as Euro 6: pre-Euro 6 vehicles need to pay fees. Enforcement is by camera and there is no sticker required. The cities aspects such as the costs, within a range, as well as the date and area.