an affidavit before the high court it cited a study report of indian school of petroleum and energy to highlight how diesel engine technology is improving daybyday it also cited a comparative study on cng versus lowsulfur diesel engines by the mashelker expert committee which said that driving a cng vehicle for one mile emits 20 more greenhouse gases than driving a diesel vehicle for one mile from the perspective of global warming the decision to switch to cng from diesel is a harmful one cng vehicle emit 80 less particulate matter and 35 less hydrocarbons however the output of carbon monoxide is five times greater than diesel the government also said that if cng is used there is a reduction in particulate matter but other pollutants show a considerable increase in fact there is considerable increase in the emission of greenhouse gases in actual driving conditionsgovt survey of old vehiclesa survey report placed before the court in 2015 by the state government was surprising as it gave a clean chit to all vehicles older than 10 years after checking by state authorities because all were found to be in good condition and were conforming to the norms the hc pulled up the government and said that the report was not bankable and ordered the gpcb rto and various other agencies to conduct an extensive survey to find more about the emission levels of diesel vehicles that are 10 15 20 and 25 years oldtimes viewon july 25 2015 to curb air pollution the gujarat high court issued two directions the first to ensure that the gas price in gujarat was in line with the price in delhi the second ordered all vehicles to use natural gas as fuel there was much chestthumping by the state government over the success in the legal battle for the reduction in gas price but the second part of the court order was forgotten the governments insistence on purchasing diesel vehicles now appears in stark contrast to its dogged approach to phase out petrolrun autorickshaws from ahmedabad and to replace them with cngrun autos the move has pushed many auto drivers to suicide even after the hc order it appears there is no effort to phase out old polluting diesel vehicles the authorities must apply the same yardstick to all private players as well as to itself