Aviation And Environment

Like our roads, our skies too are soon going to be congested with flying machines of various types. The number of passengers and freight aircraft flown by now mushrooming private airlines is fast multiplying in the Indian skies

The skies over India will see increased flying activities with the proposed launch of a new economy airline in India by the Tata Sons Limited. In addition, the modernising armed forces acquiring additional fleet of aircraft and helicopters in the coming years, will further reduce the purity of atmosphere above the country. The general public forms its opinion about the adverse impact of air pollution on environment by usually observing petrol and diesel driven vehicles, leaving harmful trails of smoke from their exhaust pipes into the clean air on the roads. But what about a great deal of damage being done to environment by thousands of air turbine fuel (ATF) guzzling aeroplanes flying overhead by releasing hazardous fumes into our biosphere? Ironically, aircraft and ATF purchased at a staggering cost of billions of dollars from a few industrially advanced countries pollute our air while the domestic
airlines earn their profit in the Indian currency.

Like our roads, our skies too are soon going to be congested with flying machines of various types. The number of passengers and freight aircraft flown by now mushrooming private airlines is fast multiplying in the Indian skies. Similarly, the Indian Air Force, presently in aircraft acquisition mode, is likely to increase its flying operations in the coming years. This development is going to be a big contributory factor in destruction of ozone and accumulation of greenhouse gases in upper layers of atmosphere.

It is estimated that on the average, one multi-engine passenger aircraft is being added every fortnight to the fleets of newly sprung up domestic carriers in India, who are engaged in a cut throat competition to fly the remotest corners of the country. Besides growing corporate sector, PSUs and state governments have also started operating own executive jets and helicopters. As a result, the volume of flying over the Indian skies has gone up considerably. Here one must not forget the domain of military aviation-air force, army, navy and the coast guard—where more than 1,000 fighter jets, transport planes and helicopters keep aloft in a routinely scheduled day and night flying. As per the estimates, aircraft movement over Indian airspace is growing at the rate of 15 per cent annually.

The impact of the aviation activity on local air quality, especially in the vicinity of airports is quite injurious to health of inhabitants. A stage has come when an aircraft lands in or takes off Delhi airport every minute and this is the stage when it leaves maximum polluting gases behind in addition to causing noise pollution in extremity. Besides encircling planes from domestic and international airlines over the airport waiting for landing clearance eject hundred of tonnes of foul fumes into the upper layers of atmosphere. Moreover, expansion of commercial flying in India on such a large scale brings in additional risks to air traffic safety endangering not only lives of passengers but also people living in the vicinity of airports. That such a distant probability can take place is corroborated by an unfortunate mid-air collision between two passenger jets over Charkhi Dadri in Haryana nearly a decade ago.

Incidentally, kerosene happens to be the principal component of ATF that is used to provide propulsion for modern commercial as well as military aircraft. Like other fossil fuels, kerosene produces carbon dioxide and water vapour as the products of combustion. As the combustion process can not be said to be entirely efficient, partial oxidation products such as carbon monoxide and oxygenated organic compounds are produced and emitted into the upper layers of the atmosphere. Hence, the extremely harmful environmental impacts arising from pollutants left behind by aircraft engine exhausts should be a great cause of concern for the enlightened citizenry.

The two main emissions produced by airliners and fighter jets are carbon dioxide and water vapour. The combustion engine also emits a combination of nitrogen dioxide and nitric oxide as well as aerosols.

Because planes fly at high altitudes, the effect of these gases and particles are magnified as they are emitted directly into the upper troposphere and lower stratosphere, where they have a direct impact on the atmospheric composition and enhance the concentration of greenhouse gases.

Carbon dioxide is considered to be the most significant greenhouse gas.

Studies have proved that it stays in the atmosphere on an average for 100 years; this means that coming generations will face the harmful effects of carbon dioxide emissions. Currently, it is estimated that 6,000 million tonnes of carbon dioxide are released globally into the atmosphere every year.

Another fall out of increasing flying activity is contrails, which are formed by water vapour and aerosol particles. Contrails, which can often be seen from the ground, are the condensation trail left behind by exhausts of highflying aircraft. The emissions from aircraft form ice clouds, which can trap heat and thus, upset the radioactive balance of the atmosphere.

Satellite images have shown that in areas where there is heavy air traffic, contrails are produced so frequently that they remain in the atmosphere and generate the formation of Cirrus clouds. Both the Cirrus cloud and contrails are contributing factors in climate change. The impact of aerosol and cloud formation could potentially have an impact on climate change leading to natural disasters and adversely affecting human health.

The harmful side effects of increasing flying activity over the Indian skies form the right cause for concern and need to be addressed. The growing menace of climate change and global warming caused by rapidly growing commercial and military flying needs to be tackled on war footing and India must not shy away from seeking international assistance in this regard.

By NK Pant