UK: Richmond's parking-fee system is based on the average amount of carbon dioxide (CO2) a vehicle produces for every kilometre it travels, information which is readily available from manufacturers.
The higher the level of emissions, the larger the fee levied.
Those who own vehicles which produce more than 225g of CO2 per kilometre will face a trebling of their parking charges. Almost all petrol sports utility vehicles (SUVs) exceed this limit.
The characteristics common to most SUVs include a large, heavy body and chassis, which in turn requires a larger engine to power it. Their body shape also leads to increased wind resistance, which causes greater fuel inefficiency.
New hybrid SUVs, which produce a lesser level of emissions, will also come under the higher parking charges because they will affect any vehicle with an engine size of three litres or more.
Owners of high-performance cars, such as sports cars and high-end luxury executive cars, will face a trebling in parking charges too, as most of these vehicles exceed the 225g cut-off point.
Under the proposals, cars producing more modest emissions will also have to pay higher charges as vehicles producing between 150g and 185g of CO2, which is the normal range for family petrol saloons, will face an increase of between 10 per cent and 30 per cent.
Only vehicles producing less than 150g will have lower parking charges. Small petrol cars, efficient diesel cars, hybrids and biofuel vehicles would fall into this category.