Clean technology

Several media reports in the past few days have brought the issue of environmental pollution back into sharp focus. One such pertained to the findings by the Centre for Science and Environment (CSE) that the pollution in Delhi is back almost to the level prior to the shift of the entire public transport fleet to compressed natural gas (CNG). The others referred to initiatives taken by the auto industry for testing hydrogen-blended CNG to run vehicles, and by the Maharashtra sugar mills to produce bio-CNG from the biomass produced as a by-product of cane processing. Indeed, while the CSE report reflects the concern over environmental degradation and the consequent global warming, the other two reports are indicative of the response "" however inadequate "" to this dreaded menace.

In fact, the auto industry the world over is under strain to cut down harmful emissions by switching to safer and cheaper alternatives to the existing fuels in view of the burgeoning cost of crude. While plant sources-based biofuels are the front-runners among novel vehicular fuels, hydrogen is increasingly in contention as a non-plant based auto energy source. The plus point for hydrogen is that it produces water vapours, instead of greenhouse gases, as exhaust. Its mileage levels are also nearly twice that of conventional fuels.

However, neither biofuels nor hydrogen can be the panacea that the auto industry is looking for to get rid of its environment-unfriendly tag. This is partly because the energy needed to produce hydrogen comes generally from existing sources and, therefore, harmful emissions will continue to remain an issue. Also, a switch to hydrogen or hydrogen-blended fuels will necessitate creating extensive infrastructure of hydrogen-filling stations. Biofuels, on the other hand, can be dispensed with from the existing infrastructure, but they have various downsides, the most significant being that they require scarce land and water to produce. If agricultural lands are used for producing biofuels, as is virtually happening for making ethanol from food, sugar and oil crops, the consequences will be disastrous.

Already, food prices are soaring and food security is threatened the world over due to diversion of corn, sorghum and oilseeds for biofuel production. Worse, forests are being cleared to give way to oil palm plantations for biofuel in countries such as Malaysia and Indonesia, and for growing sugarcane in Brazil. India is no exception as it is also taking a big gamble in putting millions of hectares under jatropha, for which neither proven cultivation and processing technology, nor evidence of environmental benefits exists. It can, of course, be argued that most of the jatropha plantations are coming up on non-cropped, partially degraded lands and hence they do not displace food or other crops.

But, this indeed may be a myopic view. A recent paper in the journal Science has stated that protecting uncultivated land saves, in 30 years, two to nine times more carbon emissions than what can be saved through the use of biofuel produced from that land. Besides, such tracks serve as vital habitats for animal and plant biodiversity. Since land availability is already under strain in India and elsewhere, the search for alternatives to the present fuels may ultimately have to zero in on clean, though not necessarily green, sources of energy.