The following article was published in September 2007.

Cars and Air Pollution - The Facts

When Islington Council circulated a leaflet to all residents in their borough on the CO2 based permit parking proposals, the council Leader, James Kempton said in it that “Carbon dioxide emissions impact on climate change and one of the contributors to rising emission levels is cars.” Although your editor personally told Mr Kempton that he was wrong at least on the latter point when he met him at a meeting in Islington, I did not have the proof immediately to hand. But it is given in an interesting document recently published by Transport for London (TfL).

This document is the TfL “Environment Report 2006” which can be found on the internet at: http://www.tfl.gov.uk/assets/downloads/corporate/Environment-Report-2006.pdf

Although the introduction by Peter Hendy, Transport Commissioner, repeats the spurious claim that air pollution has reduced as a result of Congestion Charging (see our last edition), it contains some other useful information. For example, it notes on page 7 that CO2 emissions from TfL’s own offices increased by 2 per cent over the previous year, and by 11 per cent per square metre of floor space. So much for TfL setting a good example to the rest of us. One wonders what caused the increase. Is it because they bought a lot more IT equipment, turned up the air conditioning, or what? 

Page 31 contains the really important data though. It provides estimates of the CO2 emissions from different transport modes, in 2005/2006, including a “per passenger” figure. 

Air Pollution from Cars Not Increasing 

The figure for total CO2 emissions of cars is given as 4.73 million tonnes. Even though it does not show the change from the prior year, in the previous years report, page 7, it gives estimates of total CO2 emissions in 1999, and that shows a total of 4.67 million tonnes for cars  – in effect no significant change over 7 years, and it probably fell last year.  

But Pollution from Buses Increasing 

The latest report shows total emissions from buses actually rose by 5%, including an incredible figure of 7% increase for CO2 emissions per passenger over the year. 

And Buses are Barely Better than Cars 

The other revealing figure in the table is that it shows that the average CO2 emissions per passenger for buses is 103 gms/km in London, whereas for cars it is 124 gms/km. In other words, there is not much difference. That is probably based on the average occupancy of cars of not much better than one. So if there are two of you in a car, you are almost certainly “greener” than going by bus. The figures for underground and tram travel are better, although it does not make it clear whether that data includes their total emission costs , including those from the power stations needed to generate the electricity to drive them. 

Of course all of these figures are based on TfL estimates and they provide few details of how they arrived at these figures. Knowing the preference by TfL for public transport over private vehicles, one has to bear in mind that the estimates may also be biased in various ways. 

SMMT Figures Also Say CO2 is Falling 

Cleaner new cars have saved five million tonnes of CO2 in last decade 25/06/2007 according to a recent report by the Society of Motor Manufacturers and Traders (SMMT).  SMMT economists have calculated that car makers saved nearly five million tonnes of CO2 in the last ten years - thanks to the development of cleaner, greener cars.  Average new car CO2 has fallen by 22.6 g/km to 167.2 g/km since 1997, down by nearly 12 per cent. That equates to current annual CO2 emissions savings approaching a million tonnes. “Car makers have made significant progress in cutting CO2” commented SMMT chief executive Christopher Macgowan. “Total CO2 emissions in the UK from cars have actually fallen since 1997, down 3.2 per cent from 72.2million to 69.9 million tonnes in 2005. That's despite a 16.5 per cent rise in cars on the road from 26.3 to 30.7 million.”

Cars and Air Pollution in the UK, published November 2006 

One of most interesting statements in the recent Thames Gateway Bridge report from TfL is the following statement: “Private cars (at which FOE’s hostility seems to be focussed) constitute only 10% of total UK CO2 emissions, and the position appears to be both under control and improving, largely due to technology”.  The percentage of CO2 emissions generated by road transport of the total emissions of 170 million tonnes in 2004 was 20%. Roughly about half of that is generated by cars, with a quarter produced by HGVs, a smaller amount by LGVs and a minor fraction by buses.  However the proportion generated by buses and taxis in London is probably relatively higher although exact figures are difficult to locate. 

Although new cars are relatively less polluting, as they are more fuel efficient and have better filters, the total amount of pollution generated by them is not falling as there are more cars on the road. However, the pollution from goods vehicles has been rising, and that from air transport has been rocketing upwards.  

Incidentally the largest coal fired power station in the UK (Drax) generates more CO2 than all the passenger cars combined (21 million tonnes versus 19 million tonnes).  

What to Do About It? 

Here are your editor’s comments on the problem of air pollution: 

Global warming may or may not be happening – I am one of the sceptics.  But reducing air pollution, particularly of those pollutants that are known to affect health, is surely a sensible thing to do so long as it can be done at reasonable cost.  Improving the air quality in cities such as London will make life much pleasanter and most people would be willing to pay something for that.  

But clearly, tinkering at the fringes by making minor adjustment to the rates of car vehicle tax, or introducing a higher London congestion charge for more polluting vehicles is not going to make a real difference. We don’t need “gesture politics” – what we need is some real steps to cut pollutants in total. 

Therefore the really big polluters such as power stations and industrial processes must be tackled. At the same time, transport emissions must also be improved, and that should not be done by simply stopping people from travelling, or attempting to move them all to public transport (the latter would not make much difference anyway) but by much more aggressive encouragement of technological solutions. Cars, LGVs, HGVs, buses and taxis can all be made a lot more efficient and cleaner than they are at present – in fact some cars are already remarkably improved. Even people who like to buy high performance or larger vehicles could have their needs satisfied – just look at the Lexus GS450h reviewed in a previous edition – but they need strong, but reasonable, financial incentives to make the change.   

Clearly a high fuel cost would help but it is probably not sufficient and causes problems for rural communities who have fewer pollution problems anyway. Perhaps better to have a more aggressive car license duty in terms of higher rates for more polluting vehicles. But both of these approaches are very blunt instruments and cause problems for people who have recently bought vehicles unless they are phased in gradually or only applied to new vehicles.  

In addition they are unselective about the type of pollution being generated. Carbon dioxide is not nearly as detrimental to health as other pollutants such as particulates or NO2 so the wrong incentives may actually make matters worse – for example they might encourage the use of more diesel engines which may be more “economical” but are a lot worse for certain pollutants. 

An alternative approach is simply to direct that cars must meet certain improved standards over time, if they are to be sold at all. Or you can have a “manufacturer overall average” target that they have to meet, as they have to in the USA. Such targets can be made pollutant specific of course, not just based on CO2 emissions. Such targets would probably require much more specific commitment from the European Union however and would take some years to implement.  

Another thing that would help would be to encourage the removal of older vehicles from our roads by suitable financial incentives. Expediting the renewal of the vehicle fleet, particularly of older HGVs, LGVs and taxis, would have a significant impact because older vehicles are significantly worse than modern ones in respect to pollution. 

At present, the measures being taken are in my view too weak and too mixed up with illogical emotions to really achieve much. You cannot cut air pollution significantly by simply reducing car usage, as has been well demonstrated by the London congestion tax. You need to encourage technological improvements much more forcefully such as using electric or hybrid powered buses and delivery vehicles.  Note that the EU set a target of 120g CO2/km for 2010 for cars, but that target is unlikely to be met unless more vigorous action is taken at an international level.  

But any such steps should not just target private vehicles but even more importantly goods vehicles, buses and taxis.  There should be no separate attack on the private motorist and the reductions should apply across all vehicle types.

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