The world automobile population is growing unsustainably rapidly with the growth of cities and the urban population at a preceding rate today. Since 1950, the world population has doubled, and the global number of cars has increased by a factor of 10. The global population of automobiles is expected to pass the 1.1 billion mark by 2020. The global automobile population increased by 30 percent per annum while the global human population increases only by three to four percent every year. If cities continue to grow in the typical New World style grid pattern, people will use more private vehicles, especially if there is a greater distance between the residence and the workplaces and shopping centres.
The first petrol powered automobile appeared in 1886 and by 1990 world production of automobiles was only about 20,000 vehicles per year. In 1999, it became 30 million vehicles every year. The number of automobiles (mostly cars) rose from 48 million in 1950 to 500 million in 1990, according to data and statistics. Also, other modes of transport have shown an increase since 1970. Airplanes flew about 7 billion kilometers in 1970, which rose to 12 billion kilometers in 1987. This growth in automobile numbers and distance traveled potentially means high-energy (oil and gas) use and high air pollution.
For developing countries private four-wheeler vehicles (cars) may still be a luxury for a prosperous few, but in developed countries nearly anyone possesses some or the other type of four-wheeler vehicle. There may even be two vehicles per person in the richest of rich countries like the USA and some other prosperous and fruitful nations. Worst (from the pollution point of view) is the boom of the two-wheelers (scooters/bikes) and three wheelers (auto rickshaw) vehicles in Asia and most developing countries of the world as they are more affordable and the cheapest means of individual motorised transport for the expanding working middle class. This is also because they take less road space in the crowded Asian streets. This results in comparatively large emissions about fuel consumption since most motorbikes have two-stroke engines with poor pollution characteristics as they mix lubricants with petrol.
India also experienced an automobile boom since the 1980s with the Japanese Maruti Suzuki taking over from the traditional car manufacturers Fiat and Ambassador, who dominated the industry for over four decades. Now the gates have been opened for major car manufacturers of the world, leading to a virtual explosion of automobile population in a resource starved country like India. India is projected to have 36 times more cars in 2010 than it had in 1990. China is also experiencing an automobile boom. There are about 40 per cent motorbikes in its transport fleet. It is projected to have 91 times more cars in 2010 than it had in 1990.
Environmental Impact of automobile and motorised transport system
Automobiles and motorized transport systems are greedy consumers of land, energy, oxygen and other material resources. On an average, for every 80 kilometers that each automobile travels, it uses up enough oxygen needed for one person for one month. Ther consume land for roads, parking, building railways and harbours. Parking space for about 200 vehicles occupies approximately one acre of land. Ther consume minerals and metals for the manufacture of vehicles and infrastructure development.
The automobiles and motorised transport systems alone consume 30 percent of the world’s energy and give out toxic emissions, which constitute 70 percent of global air pollution. Petrol vehicles pollute more than diesel, and the two and three wheelers are the worst polluters. Diesel vehicles emit lower amounts of carbon monoxide and hydrocarbons than petrol vehicles, but they emit 30-50 times more particulate matter. Aeroplanes and railway locomotives have far lesser emissions than road vehicles. Worldwide, millions of oxides of sulphur, nitrogen, suspended particulate matter and carbon monoxide were released, are released and are continuing to be released into the atmosphere.
Deteriorating Quality of Air in Cities due to Automobiles
In most world cities today, vehicular pollution levels often exceed the recommended World Health Organisation guidelines. Studies carried out near highways have shown increased concentrations of heavy metals cadmium, lead, zinc, nickel and chromium in vegetation and soil.
Photochemical Smog in Cities
Automobiles are the major source of photochemical smog, which plagues most metropolitan cities of the world today. The oxides of nitrogen and the reactive volatile hydrocarbons (VOCs) undergo photochemical reaction to produce more deadly secondary pollutants called ‘tropospheric ozone’ and peri acetyl nitrate (PAN). Ozone is the major component of this photochemical urban smog, which plagues several cities of the world today.
Greenhouse Gases and Global Warming
Automobiles alone emit more than 700 million tonnes of carbon every year in various gaseous forms including the greenhouse gases carbon dioxide and methane. With nitrous oxide, they are responsible for over half the global warming problem.
Health impact on Urban Residents due to Vehicular Pollution
In cities, urban inhabitants inhale vehicular pollutants on an average, which is equivalent to smoking 10 cigarettes a day. Diesel vehicles emit over 100 micro-particles, smaller than one micrometer in diameter, which are easily carried away by air currents and settle in the lower respiratory tracts of human lungs when inhaled. These particulates contain hundreds of organic compounds, several of which are carcinogenic. Researches done at Los Angeles in the USA has indicated that people who live or work 50 metres or less downwind from a major highway or busy intersection could be exposed to up to 30 times higher than normal levels of potentially dangerous air pollutants. In well-settled cities with higher pollution, thousands of people die every year due to vehicular pollution related diseases. Forty-one per cent of babies have been found to have dangerous lead levels in their internal organs, choking their cords and several babies were reported to be born without brains. Imagine the state of economy and development in a nation, where the younger generations are totally deformed, without their nervous bags!