The updated London Congestion Zone charges will lead to increased carbon dioxide emissions, according to emails Celsias has been sent from a 'green' insurance company and their PR company and is reported on the UK Clean Green Cars website.

Given it is April 1, so we are particularly conscious of bullshit, I thought I would try to untangle what is being said and whether it has any validity whatsoever.

Basically the argument is this: the London Congestion charge is being changed to exempt vehicles which emit less than 120 g/km or less. The percentage of these vehicles in the total population is increasing, and according to Clean Green Cars will exceed 10% of the total by the end of this year. The argument continues that the removal of congestion charges for this class of vehicle will lead to the increase in the number of journeys due to wealthy drivers purchasing a small second car. They state that a London commuter might expect to pay £500 ($US 1000) a month in congestion charges which could easily be offset with a smaller car.

OK, this is the press release from the London Mayor explaining the change.

First we need to ask what have been the benefits of the existing congestion charge regime and why the changes are necessary. A recent academic study on the affects on human health and air pollution of the Inner London Congestion Zone found

...little change in pollutant levels in London as a whole. But there were more substantial falls in the charging zone.. Policies affecting a larger geographical area and residential population, and which directly aim to reduce vehicle emissions, are likely to have larger public health impacts... -- Environmental Research Group, Kings College London

Let us now go on an imaginary journey. You are a top London executive, and enjoy driving around town in your Aston Martin. You are shocked to find that under the new scheme you would be liable for a £25 daily charge because your emissions are 394 g CO2/km, so you decide to buy a Smart City Fortwo coupé which emits only 113 g CO2/km, which attracts no congestion charge, and drive it three times as far (figures from here). If such people exist, they're probably as likely to chose an electric car or join a car sharing club as to buy a car simply to save money whilst driving around the congestion zone.

I'd say pricing these monstrosities off the road is worth the risk of having city executives bombing around in small cars.

Furthermore, according to figures in this report about air quality in London, whilst cars are an important source of CO2 emissions, a greater amount is produced by road freight transported in lorries and vans. This is an issue that the Mayor has also sought to tackle with the introduction of the London Low Emission Zone which will charge the most inefficient lorries £200 ($US 400) a day to enter Greater London, a much wider area than the Inner London Congestion Zone.

Of course, there is much more that needs to be done. But one wonders why a car insurance company is seeking to rubbish the changes, which appear to me to be fairly sensible steps.