Special Report on the Motor Show (11): Towards a green machine: The internal combustion engine is a polluter but great steps are being taken to perfect the cleaner car, says Matthew Carter

WHETHER you see the motor car as a scourge on society, a necessary evil or the key to personal freedom depends on where you sit.

Few enthusiasts will argue against the fact that the car is slowly choking our city centres to death while few car-haters can deny that it has transformed our lives. A necessary evil? Perhaps.

The internal combustion engine is a polluter. Worldwide, it is estimated, almost half the carbon monoxide, hydrocarbons and nitrogen oxides given off by burning fossil fuels are emitted by petrol and diesel engines. Around 18 per cent of the world's carbon dioxide, the greenhouse gas, is also directly attributable to the car.

It is a position recognised by governments and the motor industry worldwide. Ever tougher legislation seeks to reduce polluting exhaust emissions and speed up development of alternatives to the petrol engine.

In Britain, British Gas is set to convert 100 of its vans and cars to run on compressed natural gas (CNG) by the end of the year and has plans to run a further 200 on gas by the end of 1993. It is also taking steps to set up a nationwide network of gas filling stations, vital if gas is to be seen as a viable alternative to oil-based fuels.

CNG is widely used as an alternative fuel, especially in Italy, but it may not provide the full answer as CNG's main constituent, methane, is more active as a greenhouse gas than carbon dioxide.

Petrol-engined cars now happily drink unleaded fuel and since the beginning of September all are built with catalytic converters. Indeed, until a few weeks ago, EC legislation demanded that all new cars sold in 1993 should be fitted with a 'cat'. The recession, and the resulting huge stocks of unsold new cars, means the industry has been given a reprieve and 'non- cat' cars may be sold next year.

The use of the catalytic converter is already so widespread that the numbers of non-cat cars sold in 1993 will represent only 3 per cent of the total UK market.

In addition, Michael Howard, the Secretary of State for Environment, has announced that the government may impose environmental taxes on fossil fuels such as coal, oil and gas. The Society of Motor Manufacturers and Traders welcomed the news that 'any taxes used to encourage an improved environment will be applied to the use, rather than ownership, of motor vehicles'.

Efforts are also being made to prevent the car from polluting the world after its useful life is over. Experiments in Germany have brought recycling centres in place of the scrapyard. A large proportion of a car is made from metal which can easily be reclaimed, but the remainder - a cocktail of glass, rubber and different plastics - is difficult to recycle.

Manufacturers such as BMW and Volkswagen have reduced the number of different plastics in their cars. Some recycling projects are already in place, but according to a recent study by Coopers & Lybrand, more needs to be done.

Its report says that from the 13 million cars scrapped annually across Europe, about 15.5 million tons of waste is recycled, but a further 4.9 million tons is sent to landfill sites. Rover, which in conjunction with The Bird Group, a reclamation firm, is undertaking a comprehensive study into recycling, wants the Government to establish national recycling centres.

In Germany, draft legislation is under discussion which would make it compulsory for manufacturers to take back their old cars when they are scrapped.

With these and many other projects underway, the car industry is convinced it has its house in order. But while environmental groups might agree that progress has been made, they still see the car as an enemy of the planet.

Lynn Sloman, assistant director of Transport 2000, suggests the real problem is the growth in traffic on our roads. 'According to Government projections, the car population of the UK will grow by 140 per cent between 1988 and 2025. With 39 million cars on the roads of the UK by then, we will need a motorway between London and Edinburgh 275 lanes wide just to park them all.

'Our real complaint is that government policy is directed towards roads and away from improving alternative forms of transport . . . And society needs to change its attitude to the car, to become less dependent on it,' she says.

Neither is cycling the pleasure it once was. A report compiled by Travers Morgan, transport consultants, reveals that the death rate for British cyclists is among the worst in Europe, five times higher than in the Netherlands and 10 times worse than in Denmark.