The Indian automobile industry says the number of diesel cars is growing in several Western countries, so why are there complaints in India?

Michael Walsh, editor of CarLines and former air pollution control specialist at the US Environmental Protection Agency argues that, driven by concerns regarding global warming, many countries have encouraged the use of light-duty diesel vehicles. Since the diesel engine is more fuel-efficient, several Western companies have promoted diesel cars to lower levels of carbon dioxide (CO 2 ) emissions.

But, of late, governments are beginning to counter industry responses to global warming problems by diesel emission standards because of growing evidence of the health effects of diesel particles. As a result, there are wide differences in the trend in sales of diesel cars from country to country even within Europe.

Meanwhile, new evidence shows that diesel cars may not even help prevent global warming. A study by the Swedish Environmental Protection Agency points out that diesel cars use 20-25 per cent less fuel, but they emit 15 per cent more CO 2 per litre than petrol cars and, as a result, the overall effect on CO 2 emissions is "negligible'.