Published: Thursday 31 January 2008

Emissions puzzle

Is it true that emissions from a four-stroke engine contain finer particulate matter than that from a two-stroke engine?

If so, then don't you think that these particulate matters will be difficult to deal with, once they enter our respiratory system? We know that diesel engines cause more pollution than petrol engines. Then, why are car companies announcing, with much fanfare, the launch of diesel versions of their cars?

C V Krishnamurthy

our response
European studies show that two-stroke engines emit more particulate matters, up to six times higher, and nanoparticles than four-stroke engines.

Moreover, the nature of particulate matters from two-stroke engines is entirely different--they are semi-volatile hydrocarbons and are largely influenced by lubrication. This means, with controlled lubrication one can reduce particulate matter emissions from two-stroke engines.

With the use of advanced technologies such as direct injection technology and catalytic converters, particulate matter emissions from two-stroke engines can also be reduced further.

As far as emissions from diesel and petrol engines are concerned, data from the Pune-based Automotive Research Association of India show that there is an enormous difference between the actual emissions levels of diesel and petrol cars, even if both are of Euro III (Bharat Stage III) standard. Euro III diesel car emits 7.5 times more toxic particulate matters than a petrol car meeting the same emission norms.

The difference is because of the flawed emissions standards that allows diesel cars to emit more NOX and particulate matters compared to petrol cars.

Hiware Bazaar--a model village

This is in response to your editorial 'The laboratory of development' (December 31, 2007). It is heartening to read that the residents of Hiware Bazaar village brought about a remarkable change in their lives by simply noting water availability for a certain period of time and calculating their water requirements for both irrigation and domestic use.

Proper planning of water use done well in advance is their key to success. The village sarpanch , Popat Rao Pawar, has been rightly honoured. But I believe that all residents of Hiware Bazaar deserve to be honoured for abiding by the gram sabha decisions. Such village models should be promoted and replicated across the country.


Down to Earth I firmly believe that Hiware Bazaar village in the drought-prone district of Ahmednagar in Maharashtra can be a model for others. During the 1990s, I presented a paper at a conference in Stockholm, Sweden, to demonstrate the importance of tailoring the economy to suit water resources availability. My paper corroborates your experience at Hiware Bazaar.

Geoffrey J Matthews

Down to Earth I am glad that you visited Hiware Bazaar and wrote an article on its water audit. In May 2007, I accompanied some members of the International Association of Hydrogeologists, who were on a short visit to India, to meet Popat Rao Pawar and get first hand impressions of the miracle achieved by soil and water conservation practices followed over a watershed. They were highly impressed.

However, they asked me a question: "Why don't other villages in the semi-arid region of Maharashtra follow the example of Hiware Bazaar and make the state 'tanker-free' in summers?"

In Maharashtra, there is a strong tanker lobby benefiting from supplying 'tanker water' for drinking in water-scarce villages. If the state government actually wants to take positive steps to mitigate the problem, it should declare that the villages will get water tankers only for four years. Within this period, water-scarce villages must undertake soil and water conservation activities and be self-sufficient at least to meet their drinking water requirements.

Or else, villages like Hiware Bazaar and Ralegan Siddhi will remain stray examples.

Shrikant D LIMAYE

Down to Earth It is unfortunate that the current definition of development in our country is nothing beyond laying new roads and establishing more industries. As a result, our new economic activities are more concentrated in urban India, while development of villages, which constitute 70 per cent of the country, get short shrift.

In such a scenario, the efforts made by villagers in Hiware Bazaar and Ralegan Siddhi are certainly commendable. The methods they have adopted are so simple that any village can follow them easily.

The government should publicize the achievements of these villages so that they can inspire other villages, particularly places like Vidarbha in Maharashtra and Rayalaseema in Andhra Pradesh, which are experiencing increasing incidences of farmers' suicides.

V S Naidu

Down to Earth Models of villages such as Hiware Bazaar and Ralegan Siddhi, as rightly said in your editorial, should be replicated across the country. But this, to a large extent, also depends on the attitude of local people.

Take the examples of Haryana and Punjab--two economically prosperous states. People in these states have ove.

Water rights

This is in response to the cover story 'Ground Swell' (December 31, 2007). The problem is not irrigation vis--vis industry. The problem is about managing the water sector. Both agriculture and industry are important for our economy and we need water for both the sectors. Hence it is up to the sectors to improve their water usage.

I have a few suggestions to make in this connection.

Down to Earth Water entitlement criteria should be fixed for each type of industry. Water allocation should be calculated scientifically and be made public

Down to Earth Industry should carry out its own water audit and try to reduce water consumption through advanced technologies and recycling of water

Down to Earth There should be a substantial increase in water rates for industrial use based on the concept that water is an economic good

Down to Earth Installation of water meters should be made compulsory for all industries

Down to Earth The industry should also be asked to pay for rehabilitation, modernization and renovation of irrigation projects

Down to Earth Farmers should be motivated to gradually shift to diversified crops, especially those that consume less water

Down to Earth Farmers should also learn new paddy cultivation techniques, which require substantially less amount of water than traditional practices. This also applies to other water-intensive crops such as sugarcane and banana

Down to Earth Farmers should switch over to piped distribution of water, instead of open channelsfor water distribution

Pradeep Purandare

Down to Earth On November 6, 2007, 30,000 farmers from Orissa's Sambalpur district gathered to demand water from Hirakud dam. If the ongoing exploitation of water by industries continues, similar agitations will become more frequent and violent.

In the name of special economic zones, the government is blindly providing land, water and electricity to industries. What happened in Sambalpur is just a warning to the government to give a second thought to the real interest of common people.

Guru Prasad Nahak

Who is to blame?

This is in response to the article 'Business in Bali' (December 15, 2007). Though climate change is a worldwide problem, rich countries such as the us, the uk, Australia and China are primarily responsible for the environmental catastrophe. Their actions can rightly be called eco-terrorism. Developing countries such as India, Bangladesh, Nepal, Tibet, Sri Lanka have been victims of their eco-terrorism.

Ranjan Kumar Amritnidhi


Down to Earth The analysis gives a clear insight as to what needs to be done by the rich and the poor countries and the crucial role India can play in reducing greenhouse gas emissions. In Maharashtra's Aurangabad district, we have come up with a forum called Mukta Samvad Manch, where we encourage people to go for reverse integration and go back to bicycles rather than motorbikes. We are in the quest of an alternative to the polluting vehicles and machinery to curb greenhouse gas emissions without disturbing our economic growth.

Sunil Jogdeo

An interest in pests

Your articles 'No pesticides' (May 31, 2006) and 'Don't show me the money' (November 30, 2007) are highly inspiring. I am an entomologist. Currently, my department is working on alternative and cheap methods of pest management. We are also planning to run a research and extension project in some villages of Bundelkhand in Uttar Pradesh, where we can test the methods of agriculture as described by villagers in Punjab and scientists in your articles.

Sarbasis Chakravorty
B N V P G college,
Hamirpur, Uttarpradesh

Utility of nuclear power

I do not agree with the article 'Ticking away' (December 31, 2007). No doubt nuclear power sources have some problems. But this does not mean that we stop using nuclear energy for power generation.

The fear that the radiation from these nuclear plants will harm the neighbourhood is far-fetched. Disposal of spent nuclear fuel does pose a problem but there are ways to store them safely--deep in the used mines in sealed containers. There are several nuclear power stations operating across the world with an enviable safety record.

At present, when we want to combat climate change, there is an urgent need for non-fossil power facilities, and nuclear energy is the only source which is known to be less polluting despite all doomsday predictions.

Thermal power stations are polluting even with the best of technology and controls, and renewable energy sources such as solar, wind, tidal, geo-thermal and biogas have only limited applications.

D B N Murthy

Down to Earth I absolutely agree with the points made in your article. It is sad that those who are advocating the need of nuclear power do not even bother to ponder over the dangerous implications inherent in the deal. It is time that they should rethink over the issue before arrival of nuclear power in the country. Are we ready with the perfect solid waste management schemes to handle the nuclear wastes? How can we be sure that our policy makers are not pushing us towards another Chernobyl accident--the world's worst reactor accident that occurred at Chernobyl, Russia, in 1986.

Arvind K Pandey

More study on acid rains

Your article 'Corrosive showers' (October 15, 2007) is an interesting report on acid rain.

The data from 10 global atmosphere watch network stations provided in the article are very informative.

You have also said that in most parts of India, alkaline dust in the atmosphere neutralizes the acid content in rain. This alkaline dust is a boon for us. However, with increasing emissions of sulphur and nitrogen in the atmosphere, I fear the situation might not be the same any more. It is time that researchers carried out a detailed study of acid rain once again. Highly ecological sensitive areas should be given prime focus in the study.

Also, there is an urgent need to estimate that how much dust contribution is from India and how much is due to the long-distance transportation of dust from neighbouring regions.

Umesh Kulshrestha

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